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Leaking tunnel and Jettison of the LM Journal Home Page Day 10: Orbital Science

Apollo 15

Orbital Science and Crew Rest

Corrected Transcript and Commentary Copyright © 1999-2008 by W. David Woods and Frank O'Brien. All rights reserved.
Last updated 2016-06-21

[This is August 3, 1971, the ninth day of the Apollo 15 mission.]
Public Affairs Officer - "This is Apollo Control; 185 hours, 41 minutes Ground Elapsed Time, in the mission of Apollo 15. Command/Service Module Endeavour with all three crewman asleep at this time. Now midway through the 55th lunar revolution with 21 minutes left before Loss Of Signal [LOS] on this revolution. Apollo 15 is now 55.4 nautical miles [102.6 km] above the lunar surface in an orbit measuring 52.2 [nautical miles, 96.7 km] at pericynthion and 66.7 [nautical miles, 123.5 km] at apocynthion. Current velocity 5,369 feet per second [1,636 m/s]. Spacecraft weighs 36,310 pounds [16,470 kilograms]. Earlier in this revolution the Lunar Module Pilot's heart rate was down in the mid 50's, which was a fairly good indication that he was, if not asleep, almost asleep. Cabin is holding at 5.2 pounds per square inch [35.9 kPa]; cabin temperature, 69 degrees [Fahrenheit, 20.5°C]. Some 7 hours and 47 minutes remaining in the crew sleep period. Currently in operation are several of the orbital science experiments in the so-called SIM bay, our Scientific Instrument Module in the Service Module of Apollo 15 spacecraft: VHF bistatic radar experiment and the Gamma-ray experiment and the X-ray. At 185 hours, 43 minutes; this is Apollo Control."

Public Affairs Officer - "This is Apollo Control at 189 hours, 59 minutes Ground Elapsed Time. Just had Loss Of Signal with the Command/Service Module Endeavour on the 57th revolution - nearing the end of the 57th lunar revolution. Current altitude: 52.4 nautical miles [97.0 km]. Endeavour now in a 66.9-nautical mile by 52.3-nautical miles [123.9- by 96.9-km] lunar orbit. Crew is still asleep at this time; some 3 hours, 29 minutes remaining in the scheduled sleep period. During the last front side pass, during revolution 57, the Lunar Module Pilot, the only one of the three instrumented for biomedical telemetry, showed a mean heart rate of about 54 - in the mid range of 50. Cabin pressure was holding slightly over 5 pounds per square feet - per square inch that is [34.5 kPa]. Temperature 67 degrees [Fahrenheit, 19.5°C]. At 190 hours and 1 minute Ground Elapsed Time, this is Apollo Control."

Public Affairs Officer - "This is Apollo Control at 191 hours, 44 minutes. Apollo 15 - Endeavour is nearing the end of the front side pass of the 58th lunar revolution. The crew is still asleep, 1 hour, 45 minutes left in this rest period. We have changed shifts here in the control center. Flight Director Gerry Griffin has relieved Flight Director Gene Kranz. CapCom now is astronaut Joe Allen. ... At 191 hours, 45 minutes; this is Mission Control, Houston."

[The late jettison of the Lunar Module yesterday evening has delayed the crew's planned 9-hour rest period. Mission Control have cut them some slack because, at Al Worden's first call of the day, it is 9½ hours since he last spoke to them. Because of this late start, there are over three pages of Flight Plan activities which must be rescheduled or deleted.]

[Flight Plan pages 3-296, 3-297, 3-298, 3-299, 3-300, 3-301, 3-302, 3-303 and the current page, 3-304.]

192:45:11 Worden: Hello, Houston; Apollo 15.

192:45:16 Allen: Good morning, Alfredo. This is Houston.

192:45:22 Worden: Good morning, Dr. Joe. How are you?

192:45:29 Allen: Couldn't be better, Al. How's it going?

192:45:32 Worden: Just fine, Joe. You all talked out?

192:45:34 Allen: No, sir. Just getting ready to start. And, pleased to have a chance to talk to you.

[Joe Allen was the EVA CapCom for Dave and Jim while they were on the surface and has had little chance to talk to Al over the past four days.]
192:45:39 Worden: Very...

192:45:41 Allen: I've got all kinds of things for you, Al, when you...

192:45:43 Worden: Very good, Joe. Glad to be talking to you.

192:45:45 Allen: Okay. I've got all kinds of things for you, which I can start handing it up to you at your convenience, pretty much. We're going to change the Flight Plan around a little bit - primarily, lifting out things because of our getting a somewhat later start than normal, and a couple of other minor modifications. I also have a lot of news to read to you and some other good things you might be interested in. Over.

192:46:15 Worden: Okay, Joe. Let's - why don't you give me a couple of minutes here to get some pens and the Flight Plan out and - and in about 5 or 10 minutes or so, I'll have the guys put the headsets on and we'll all listen to the news.

192:46:30 Allen: Al, out of curiosity, is everybody awake up there?

192:46:37 Worden: Yeah, man.

192:46:39 Allen: Good morning, Davy...

192:46:40 Worden: Yes, Joe, sure are. We're just in the middle of breakfast.

192:46:45 Scott: Hello, Joe. How are you?

192:46:46 Allen: Well, I'm fine, D.R.; how are you today?

[Allen is using the initials of Dave Scott's forenames, David Randolph. His middle name comes from the fact that he was born on Randolph Air Force Base on 6 June 1932.]
192:46:50 Irwin: Morning, Joe.

192:46:51 Scott: Oh, we're in great shape. Hey, you sure did a fine job for us down there, Joe. Jim and I'd like to really thank you. That was a superfine job of taking care of everything for us.

192:47:01 Allen: I think the superfine job is the two of you; it was just most remarkable. Everybody down here is still floating so high, they're having a hard time getting down to all that data you gave us. And you'll be interested to know that - that we have sitting in front of us, a preliminary report from each EVA of the geology of the area that I would say is more complete than our 90-day preliminary reports which were issued on some of our other landings. It's just most exciting.

192:47:38 Scott: Well, it's because you've got the real professional backroom there. Those - those guys really know how to put - put it together. Especially with the way they were coming up with the new ideas, while we were on the surface. That was really neat.

192:47:52 Allen: And, Dave, I do have to ask you one question. Is there a three-unit segment of deep core stems some place in that Command Module?

192:48:02 Scott: Joe, we wouldn't lose sight of that for all the tea in China. That's number 1 priority.

192:48:09 Allen: Yes sir. [Long pause.]

[The deep core sample was one of the major frustrations for Dave on the surface as it proved very difficult to extract, costing both time and a trip to visit the North Complex at the Hadley landing site. In addition to the problems of trying to pull the core stem out, they found that a vice, mounted on the Rover for the specific task of dismantling the six half-metre sections, was fitted backwards and unable to grip the stem. By other means, Dave got three sections free but they collectively decided to bring the remaining 1½-metre length back to Earth intact. In view of how much Dave has invested in this section he would not let it out of his sight.]
192:48:37 Scott: Oh, as a matter of fact, Joe, we made a good thorough search of the LM before we let it go. We went from top to bottom to make sure we got everything, and I'm sure we got everything we brought up off the surface, and I'm pretty sure we did - did fairly well cleaning up the surface.

192:48:55 Allen: Okay, Dave. Good news; good news. Al, if you're ready, I'll start hitting you with a few things we're interested in knowing from you right away. And then, when we get those, I'll give you the general plan for the day. And I think, in some cases, we'll want to just talk you through some of the changes while you're making your front-side pass. There's no need to feed up all the data in detail to you at the beginning here. My first question: we need from you a configuration of panel 230, particularly - in fact, only really the Mass Spec. switches, could you - call out the settings for the Mass Spec., Experiment switch, Ion Source switch, Multiplier switch and Discriminator switch, please.

[Panel 230 is the control panel for the SIM (Scientific Instrument Module) bay.]
192:49:48 Worden: Okay, Joe, I'm right there. Experiment is up and On. Ion Source is centered. The Discriminator is Low and the Multiplier is Low.

192:50:03 Allen: Okay, thank you. That's - that's what we'd guessed. And, Al, I - I guess the first thing we want - we're going to want you to do today is to start to get ready to go plus-X forward, P20 option 5. We're going to want you to retract the Mass Spec. boom and close the X-ray and Alpha Particle cover.

[Allen is covering some of the tasks which were in the timeline through which they have slept.]

[Overnight, Endeavour has been orbiting the Moon with its main engine facing the direction of flight, the so-called Minus-X Forward SIM Attitude. This attitude not only points the SIM bay at the surface below, it also aims the inlet of the Mass Spectrometer in the direction of flight so as to ram any molecules of the tenuous lunar atmosphere into the sensor. They are finished with this period of operation and want to change to a pointy-end-forward attitude with the SIM bay still looking down. This turnaround maneuver is always preceded by a manual roll of the spacecraft 40° clockwise. If they do not do this, there is a strong possibility that the turnaround will cause the IMU to enter gimbal lock, a condition that would cause it to lose its alignment.]

[Terminating this use of the Mass Spectrometer includes the retraction of its boom, an operation which has been giving some problems on previous attempts.]

192:50:21 Worden: Okay, Joe. We'll do all that. How about putting it on a - on a time basis for me so I can write it in the Flight Plan.

192:50:44 Allen: Okay, real fine. You can start that right now at - just put it in at 192:52, I guess. And also, right after that, list fuel cell purge, H2O dump and LiOH canister change.

[Allen is essentially trying to hustle Al through the most important housekeeping tasks that need to be done to cover the missed period between the planned and actual wakeup times.]

[Worden, from the 1971 Technical Debrief - "You never know what the configuration of the SIM bay is. I think that's particularly true with the three of us in the CM and all of us operating the SIM bay. We never knew if the booms were in or out, whether the experiments were on or off, and just what was going on in the SIM bay. I think that added to some of the confusion."]

[Scott, from the 1971 Technical Debrief - "That's right. And in retrospect, it seems to me the best plan, with three people in the CM running the SIM bay, is to assign one man to do nothing but SIM bay operations. Let him concentrate 100 percent on SIM bay, and the other two people can do the stowage, cleanup, and fix the meals. With three trying to run the SIM bay, I'm sure we all weren't very well coordinated."]

192:51:30 Worden: Okay, Joe. Understand. You want us to go ahead into plus-X P20 SIM bay attitude, and pull in the Mass Spec. and the Gamma-ray booms, and, I guess, turn off the Mass - turn the Mass Spec. to stand by.

192:51:46 Allen: Al, let me hit you with that last statement again. We want you to retract the Mass Spectrometer boom, but not the Gamma-ray, and close the X-ray and Alpha Particle covers. Retract Mass Spec. boom and close two covers. Over.

192:52:09 Worden: Okay, understand. You want us to pull in - to retract the Mass Spec. boom and close the X-ray [and] Alpha covers, then do the fuel cell purge, the water dump and canister change.

192:52:22 Allen: That's affirm.

192:52:28 Worden: Okay, Joe. I'll get that in work.

192:52:36 Allen: And one more item. You can start to charge Bat B at your convenience.

[The CSM's online batteries are regularly recharged during the flight as they help cover extra power demands from the spacecraft's systems. At the end of the mission, they will be used to power the separated Command Module during the re-entry into Earth's atmosphere. This charge was due at 189:00. The replacement of the lithium hydroxide canister was due at 192:00 and requires that canister 16 replace number 13 in the A receptacle, 13 being stowed in compartment A3. The purge and dump were due in an hour.]
192:52:46 Worden: Okay. [Pause.]

192:52:56 Allen: Okay, and looking downstream here, as soon as you get turned around, and these other good things done, we're going to ask you to open the X-ray and Alpha Particle covers. And for rev 60, the [current] agenda calls for an eat period for you. And Gamma-ray, X-ray and Alpha Particle data being taken during that time. Sounds like you've got your eat period pretty well out of the way.

192:53:27 Worden: Yes, that's right, Joe.

[Long comm break.]

[There is an eat period scheduled during rev 60 which lasts from 194:30 to 195:30. Allen seems to be confirming that they have just eaten their breakfast, presumably so that the later meal break can be used for rescheduling missed tasks.]

192:56:34 Worden: Houston, 15.

192:56:37 Allen: Go ahead, Al.

192:56:40 Worden: Okay, Joe. While we're maneuvered here to a plus-X forward, how about reading some news to us?

192:56:45 Allen: Okay. Sure will. Let me - let me begin with just a note on that water dump. It'll take about 15 minutes to run, and they're interested in your dumping it to close to 10 percent onboard reading. Over.

192:57:04 Worden: Roger, understand. Probably the same as we've been doing before. We dump down to 10 percent, but not below 10 percent.

192:57:12 Allen: That's correct. And I've got several things to read to you here. I have the official morning Gold Bugle Zeitung report and - that comes from two rows behind me here. And I've also got a telegram for you, Jim. And I have some history - a little bit of history that's been researched for you by the people at Honeysuckle concerning a small problem with a leak on the Endeavour about 200 years ago. And I'll start with whatever you'd like to hear first.

192:58:07 Worden: Okay, Joe. Go ahead.

192:58:09 Allen: Okay, let me just start with the morning's news. The weather report in Houston-Galveston area calls for showers and thunder showers through Wednesday. Today's temperatures will be in the lower 70s and upper 80s.

192:58:09 Allen: The United States will support Communist China's admission to the United Nations this fall, Secretary of State, William Rogers announced. The U.S. will also fight against expelling the Nationalist Chinese Government on Taiwan. U.S. Steel, the industry pace setter, announced a price hike averaging 8 percent on virtually all its products and several other companies followed suit, as an aftermath of a new 3-year labor contract. Trainmen won pay increases of nearly a dollar and a half an hour, spread over a 42 months, in a nationwide contract settlement, and called off their crippling strike against ten railroads. The union yielded on the railroad's demands for some work-rule changes, yet to be worked out. Among those viewing Apollo 15 activities, Monday, in the MOCR, was artist Robert McCall, designer of the commemorative stamp for Apollo 15. And just an edited note here: He was also making sketches of the scenes down here as he saw them and he would turn them out almost as fast as the photographer would take pictures. That was most interesting. Turning to the sporting news, Don Wilson pitched a two-hitter and Jesus Alou drove home the winning run and then made a game-saving catch as the Houston Astros downed the Chicago Cubs, 2 to 1. And, apparently, rain is slowing up the Oilers' preparations for the Giants. The Oilers/Giant exhibition game is scheduled for Monday night in the Astrodome. And I've got the Monday's baseball scoreboard - which I'll run through quickly for you baseball fans. In the American League: Boston 7, Baltimore 4; New York 7, Cleveland 0; Oakland 2, Kansas City 1; Chicago 7, Minnesota 5; Detroit 11, Washington 7; California 3, Milwaukee 1. Readback.

[Joe's excellent and quick sense of humour turns a list of baseball scores into another reading of Pre-Advisory Data (PAD) which are always read back to Mission Control for verification.]
192:59:38 Allen: Disregard...

192:59:38 Worden: Roger, Joe. Copied all these off.

192:59:38 Allen: Roger. Okay. In the National League: Philadelphia 4, Atlanta 0; Cincinnati 4, New York 2; St. Louis 3, San Diego 1; and Los Angeles 5, San Francisco 4. And Lee Trevino added another thousand bills to his bank roll, Monday, by taking first place with the number ... with a 7-under-par, 65, in the Colombus Invitational Pro-Am. Jack Nicklaus and Arnie Palmer teamed last weekend to close in on Trevino in professional golf's money-winning race, though. Nicklaus and Palmer won twenty thousand dollars each when they won the National Team Championship at - I guess Ligonier, Pennsylvania. Trevino leads for the year with a total of nearly two hundred thousand dollars.

[Flight Plan page 3-305.]
193:01:36 Allen: And, I'll go over now to - Jim, a special telegram for you which reads, essentially: Mother, Dad, and your brother Charles are proud of you. We were thinking of our trip together on top of Mount Whitney and we are with you in spirit on the Moon. Love, Mother, Dad, and your crew. And I might add, that there - An occasional piece of mail for all of you that is starting - is starting to come in to the Manned Spacecraft Center, here. In fact, I think a truck pulled up there yesterday to deliver some of the first.
[Woods, from 1999 correspondence - "Did NASA heap a lot of PR work on you when you returned or did they give you decent grace to debrief, unwind and get your bearings again after the flight?"]

[Scott, from 1999 correspondence - "The former - and I wish we had had the latter. But NASA was a very large organization, and we were essentially 'transferred' to the PR world after the flight; and during those days there was very little sensitivity to the issues you suggest. Actually, it would have been best if we had had a quarantine period of three weeks or so as did previous flights, just to rest up and get ready for the next push (which I requested of Slayton but to no avail). But no complaints really, we did get to go on some fabulous and memorable trips which we would trade for nothing."]

193:02:17 Allen: I'm going to go on, if you're still listening, to read some history that was sent to us by the Honeysuckle people. And the subject is "A Leak on the Endeavour at 62 hundred GET." Following the above incident and the wonder from the Apollo 15 crew whether Captain Cook's Endeavour had ever sprung a leak, the staff at Honeysuckle Creek Tracking Station has searched the records and come up with the following incident, which may be of interest. Information has been extracted from an old newspaper article and an entry in Captain Cook's log book. "It was 11 p.m. on June 11, 1770, a clear moonlit night, when His Majesty's Ship, Endeavour, under the command of Captain James Cook, sailed serenely under fully furled sail within the waters of the Great Barrier Reef off Australia's northeast coast. Then disaster struck. The ship had got upon the edge of a reef of coral rocks which lay to the northwest of having come in places [sic] run the ship 3 or 4 fathoms and in others about as many feet." And I'm quoting James Cook's diary here. "But about a hundred feet from her starboard side, she, laying with her head to the northeast were 7, 8, and 10 fathoms." With a grind and a roar, the Endeavour rose in the bow, and came down hard. Empty water. Casks broke their lashings and lay in a tangle with the rigging on the deck. The captain, clad only in drawers, which I guess is a Constant Wear Garment, rushed on deck. He summoned all hands to the pumps, and ordered all unnecessary stores to be thrown overboard. Such items as iron, and stone ballast from deep in the hole, casks, hoops, stays, oil jars, decayed stores, and then six cannons, which fired 4-pound shot. (Probably one cannon to fire long, one cannon to fire short and two to fire for effect.) These, in fact, are the cannons discovered in 1969, off the coast of northeastern Australia by a team from the Philadelphia Academy of Natural Science. And, after restoration, one each was presented by the Australian - to - by the Australian government to the U.S., British, and to New Zealand. The remaining three cannons are in Australia. The original Endeavour was finally freed from the reef by means of oakum and wool, wrapped in a sail, being sunk under the ship and plugged into the hole in hope that it would be sucked into the leak and would close the leak. The experiment was entirely successful and, I quote again, from Cook's diary, "In about a quarter of an hour to our great surprise, the ship was pumped dry and upon letting the pumps stand, she was found to make very little water." Subsequently, the Endeavour arrived at the Australian mainland, the landing place is now called Cooktown, by the way, and after two months the damage had been repaired and the ship returned to England. And that's the end of your history lesson for today. Over.

193:05:43 Scott: That's quite an analogy, isn't it.

193:05:48 Allen: Quite an analogy, Dave. Certainly is.

[Journal reader, Andrew Field, points out that Captain Cook's Journal is available online from the National Library of Australia. from this resource, we can get exact quotes for the passages given above. For the entry where the ship is grounded, it says "Before 10 oClock we had 20 and 21 fathom and continued in that depth untill a few Minutes before a 11 when we had 17 and before the Man at the lead could heave another cast the Ship Struck and Stuck fast. Emmidiatly upon this we took in all our sails hoisted out the boats and sounded round the Ship, and found that we had got upon the SE edge of a reef of Coral rocks having in some places round the Ship 3 and 4 fathom water and in other places not quite as many feet, and about a Ships length from us on our starboard side / the ship laying with her head to the NE / were 8, 10 and 12 fathom." When the crew try to lighten the load, it says "We not only started water but throw'd over board our guns Iron and stone ballast Casks, Hoops staves oyle Jars, decay'd stores &ca, many of these last articles lay in the way at coming at heavyer. All this time the Ship made little or no water."]
Allen (continued): Back to reality. Al, I have a CSM consumables update for you if your interested in that. And let's see - the other item on my desk - Well, I'll get to it a little later. I'll be standing by for your go-ahead on the CSM consumable update.

193:06:17 Worden: Okay, stand by, Joe. [garble]

[Comm break.]
193:07:36 Worden: Houston, 15. I'm ready to copy the consumables, Joe.

193:07:40 Allen: Okay, Alfredo. GET 191 plus 25; RCS total, 47 [percent]; quad A: 50, [B] 47, [C] 46, [D] 47; H2 tank 1: 56, [2] 53, [3] 42; O2 tank 1: 64, [2] 67, [3] 54.

193:08:19 Worden: Roger, understand, Joe. At 191:25, RCS total, 47; quad A: 50, 47, 46, 47; H2 is 56, 53, 42; O2 is 64, 67, 54.

[Though the major events of the flight have passed, they have barely used half of their critical consumables. This reflects the margins built into the system to cope with credible emergency situations. For example, if there had been an Apollo 13-type abort or the CSM had been called on to rescue the LM from an off-nominal orbit.]
193:08:49 Allen: Copy, Al. And I'll be right back.

193:08:54 Worden: Okay, Joe. [Long pause.]

193:09:37 Allen: Endeavour, this is Houston again.

193:09:42 Worden: Go ahead, Houston.

193:09:44 Allen: Okay, Al. Let me lay some more words on you concerning your Flight Plan, when you're - you're ready to talk about that.

193:09:55 Worden: Roger, Joe. Go ahead.

193:09:58 Allen: Okay. You'll be in the configuration plus-X forward, and will be taking Gamma-ray, X-ray and Alpha Particle data, data during rev 60. We want you to do, at 193 plus 45, a P52 option 3. And we're going to add a Map and Pan Camera pass sometime during rev 60. And I'll be coming at you with the necessary data for that. Also...

[Allen is replacing the P52 guidance platform realignment scheduled for 190:15. This will realign the platform to the orientation of the landing site at the time of lift-off, known as the lift-off REFSMMAT. During the three hours this morning when the crew caught up on their rest, periods of photography by the Mapping and Panoramic Camera were also scheduled which must now be given time later.]
193:10:51 Worden: Roger, Joe; understand.

193:10:53 Allen: Okay, Al. Now I guess a - a word about biomed configuration, today. In order to get some very interesting baseline data, medical data on you, Al - and, Jim, for your EVA coming up later - we're requesting that the two of you give us that biomed data today. I think, Dave, you were scheduled for it, but I guess we'd prefer Jim on the line with Al to get baseline data for later. Now, Al, let - let me run through in just some blocks here, [of] the next revs as we see them, and the approximate activities. And then I'll come up with specific data concerning those revs later on, perhaps actually during the revs. On rev 61, we're going to have the UV...

[The requirement for Jim to wear his biomedical sensors may be linked to heart irregularities spotted by the Flight Surgeon while on the Moon.]
193:12:54 Worden: Roger that.

193:12:54 Allen: Okay. On rev 61 will be UV photography of the lunar mare. We're coming up on, I guess, an hour of light flash experiments, and it's pretty much dealer's choice between Dave and Jim, who - whichever one of you would like to do that. Rev 62 will be a crew exercise period, science photos, and science visuals. And we'll be taking the Mapping Camera and Laser Altimeter data during rev 62. And it will end with terminator photos. On rev 63, more Mapping Camera, Laser Altimeter, and a burst of the Pan Camera. UV photos and terminator photos again. Rev 64 will be eat period, boom photos, LiOH canister change; and that brings us to about 204 hours, and it'll be time to go to bed again. Over.

[This outline roughly follows the Flight Plan anyway.]
193:13:08 Worden: Okay, Joe. Understand in the Flight Plan that the object is going to be to get us back to the printed Flight Plan as much as possible.

193:13:18 Allen: That's exactly right, Al. And you'll be coming on to it kind of as the day progresses. We're just going to pick up a few quick items that we've missed over the past 2 hours and mainly just lift - lift out other sections, as I understand it. But you'll be back on the Flight Plan shortly.

193:13:40 Worden: Okay, Joe. Fine. Thank you.

193:13:41 Allen: Roger. And...

193:13:42 Scott: And, Joe, let me request that Jim be...

193:13:48 Allen: Go ahead, Dave.

193:13:51 Scott: I'd like to say that I'd like to have Jim without his sensors on today. That 3 - 4 days in a row is pretty tough with those things on. I think probably, if we get him tonight, you could probably get your data, don't you think?

193:14:10 Allen: Stand - stand by, Dave, and I'll - let me double check,

193:14:26 Scott: Say, as a matter of fact, Joe, why don't you give Jim and Al both a break today on the sensors, and I'll stick mine on, because I've had them off since we got back yesterday. And then if you want us to have some particular data-gathering periods, why don't we take a look at that starting tonight, huh?

193:14:46 Allen: Okay, Dave. That sounds good.

193:14:51 Scott: Okay. And concerning the light flash things - Jim and I both saw light flashes while we were on the surface, as a matter of fact.

193:15:01 Allen: Okay, copy that, Dave. That's remarkable.

[Long comm break.]
193:20:51 Allen: Good ship Endeavour, this is Houston.

193:20:59 Scott: Go ahead, Houston.

193:21:02 Allen: Roger. On our downlink data, we see indications of High Gain Antenna yaw fluctuations. Wonder if you could glance over at your onboard indication and see if you see it there as well. And, also we're standing by for crew status reports, when you're ready to give it.

193:21:31 Scott: No, we - we see no oscillations up here, Joe.

193:21:34 Allen: Okay, thank you.

[Comm break.]
193:22:38 Allen: Al, this is Houston. With a TEI-62 PAD, when you're ready for that. We also have a question. How did the Mass Spec. boom retraction go? And we've got a switch setting for your Mass Spec. when you're ready.

193:22:58 Worden: Okay. Jim will be ready to copy a TEI PAD here in a minute. And Mass Spec. boom retracted without a hitch this time, Joe. Sorry I didn't get the time on it, but it was very close to the nominal time, and apparently it didn't hang up this time.

193:23:15 Allen: Okay, fine, Al. Thank you. We'd like the - I guess the Mass Spec. placed on Standby, please. And that's the Experiment switch.

193:23:26 Worden: Okay. Mass Spec. on Standby. Yes, that's verified on standby, Joe.

193:23:38 Allen: Thank you. [Pause.]

193:23:47 Irwin: And, Joe, I'm ready to copy that TEI PAD.

193:23:51 Allen: Okay, Jim, good morning. We need Accept, and we're going to uplink a new state vector to you.

[The state vector is a collection of seven values stored within the computer which define the spacecraft's position and velocity along three orthogonal axes at a specified time. The computer uses it to do calculations concerning the spacecraft's motion. After a time, small errors in these calculations build up and at regular intervals, Mission Control compare the spacecraft's state vector with one they calculate themselves based on radar tracking from Earth. If necessary, they can upload a revised state vector to the CSM by having the crew place the Up Telemetry switch from Block to Accept.]
Allen (continued): And here comes the TEI-62 PAD. SPS/G&N; 36310; plus 0.61, plus 0.92; 200:10:34.64; plus 2928.4, plus 0190.3, minus 0043.5; 180, 106, 006. The rest is NA. No comment. Ullage: Four jets, 12 seconds. Over.

[An interpretation of the PAD follows:

Purpose: This PAD details a burn which would, in an abort situation, be made to return Apollo 15 to Earth. It would occur towards the end of the 62nd orbit.

System: The burn would be with the SPS engine under the control of the Guidance & Navigation System.

CSM Weight (Noun 47): 36,310 pounds (16,470 kg).

Pitch and yaw trim (Noun 48): 0.61° and 0.92°. These are the angles for pointing the SPS engine bell to ensure its thrust acts on the spacecraft's centre of gravity.

Time of ignition, Tig (Noun 33): 200 hours, 10 minutes, 34.64 seconds.

Change in velocity (Noun 81), fps (m/s): x, +2,928.4 (+892.6); y, +190.3 (+58.0); z, -43.5 (-13.3). Velocity components are expressed with respect to the local vertical/local horizontal frame of reference.

Spacecraft attitude: Roll, 180°; Pitch, 106°; Yaw, 6°. These attitudes are expressed with respect to the lift-off REFSMMAT.

Other items in the standard form are not applicable (NA) to this burn.

SPS propellants are settled in their tanks by firing the plus-X thrusters on all four quads around the Service Module for 12 seconds.]

193:24:57 Irwin: Okay, Joe. The readback on TEI-62. SPS/G&N; 36310; plus 0.61, plus 0.92; 200:10:34.64; plus 2928.4, plus 0190.3, minus 0043.5; 180, 106, 006; four jets, 12 seconds.

193:25:28 Allen: Okay, Jim. Readback correct. And how are you doing this morning?

193:25:37 Irwin: Fine, Joe. Had a good night's sleep.

193:25:42 Allen: Super. [Pause.]

193:25:49 Worden: Okay, Joe, I've got a clear status report for you.

193:25:52 Allen: Go ahead.

193:25:58 Worden: Okay. Longest 9 hours sleep in one period there, Joe, to begin with. And the PRD's are 25024, 08031 and 23175.

193:26:19 Allen: Okay, Al, copy that. And assume there was no medication.

193:26:26 Scott: That's affirmative.

193:26:28 Allen: Okay, thank you, Dave. [Long pause.]

193:26:43 Allen: Endeavour, you can go back to Block. You have a new state vector and we're standing by to watch your water dump.

193:27:00 Scott: Okay, Joe, crank out the water dump. Want to watch one for a change, huh?

193:27:06 Allen: Roger, lay it on us.

[Long comm break.]
193:32:57 Allen: Hello, Endeavour. This is Houston with a Map Camera photo PAD when you are ready.

193:33:06 Irwin: Stand by one, please, Joe.

193:33:07 Allen: Roger.

[Comm break.]
193:35:44 Worden: Houston, 15. Go ahead with your Mapping and Pan Camera photo patchup.

193:35:49 Allen: Okay, Al. And I - I forgot to tell you when you are dumping water, you can also go ahead with the urine dump if you need to do that. I just forgot to mention that. The Map Camera photo PADs for rev...

193:36:03 Worden: That's okay, we're doing it.

193:36:04 Allen: Yes. For rev 60. T-start, 194:35:05, T-stop, 195:34:50. Image motion setting at T-start: barber pole plus 4; At 195 plus 20 plus 00: barber pole. And a couple of notes on this. Be sure to retract the Gamma-ray boom prior to the start of the camera pass. And be sure to go to 5 degrees deadband in P20 - I'm sorry, Al; that's 5/10ths of a degree deadband in P20 prior to camera pass. And you want to extend the camera and start the Laser Altimeter per the system's checklist, page S/1-38. Over.

193:37:41 Worden: Roger, Joe. Understand. Mapping Camera photo PAD: T-start, 194:35:05; T-stop, 195:34:50. Now for the image motion, you want a T-start barber pole plus 4, and at 195:20:00, you want that increased to barber pole. And notes: Retract the Gamma-ray before taking the pictures; go to half degrees deadband; and extend the Mapping Camera; and start the Laser Altimeter as per system's checklist S/1-38.

[Whereas the science instruments in the SIM bay do not require accurate pointing, the Mapping Camera does. The deadband, the allowable error in the spacecraft's attitude before corrective jet firings are made, must therefore be narrowed from 5° to ½°. The tracking program in the computer, P20, takes care of keeping one side of the spacecraft aimed at the Moon and this is where the new value must be entered.]
193:38:15 Allen: Sounds good, Al. Thank you.
[Comm break.]
193:41:16 Allen: Endeavour, this is Houston with the new O2 heater configuration for you.

193:41:25 Worden: Okay, Houston. Go ahead.

193:41:27 Allen: Roger, Al. We want O2 Heater in tank 3 to Auto and tanks 1 and 2, Off. Over.

193:41:40 Worden: Understand, Joe. You want O2 Heater in tank 3, Auto, and the other two, Off.

[The heaters within the cryogenic storage tanks can be controlled automatically to keep tank pressures within limits. Pressure switches route power to energise motor-driven switches which, in turn, route current to the heaters when required. During periods of low power consumption, heat leakage from the tank's ambient environment can be enough to keep the tank pressurised and its contents flowing properly to the fuel cells and ECS (Environmental Control System). Otherwise, the heaters will come on to restore feed pressure.]

[This request from Allen is instead of a couple of lines in the Flight Plan which call for the exact opposite. (Tanks 1 & 2 to Auto, tank 3 to Off.)]

193:41:46 Allen: That's right, Al. And we want you to proceed with your O2 fuel cell purge listed at 193 plus 58 in the Flight Plan.

193:41:59 Worden: Roger, Joe. We'll get that in work here now.

[Comm break.]
193:44:38 Allen: Al, this is Houston. You can terminate the dump now. And turn the Alpha Particle experiment Off, please. [Long pause.]

193:45:30 Allen: Endeavour, Houston. Requesting Auto in the High Gain [Antenna]. And, troops, you may have to delay the P52 we've called out to you and coming up shortly until about 194 plus 20, to make sure most of the water is out of the way. Over.

193:45:56 Worden: Roger, Joe. I'll just go take a look here and see - If I can pick up the star okay, I'll go ahead and do the P52.

[To accomplish a realignment of the guidance platform, Al has to sight through the spacecraft's optics at two stars. Experience on previous flights has shown that soon after a water or urine dump, it can be difficult to distinguish the stars among the cloud of tiny ice crystals reflecting the sunlight. However, as they have just passed into lunar night a few minutes ago, this will not present a problem and Al can proceed with the task.]
193:46:02 Allen: Okay, Al. And you got the call about the Alpha Particle counter, I hope.

193:46:11 Worden: Right. Roger. We got it turned off.

193:46:14 Allen: Thank you, sir.

[Long comm break.]
193:51:12 Worden (onboard): Houston, 15.

193:51:13 Worden: Houston, 15.

193:51:15 Allen: Go ahead.

193:51:19 Worden: Okay, Joe. I got the gyro torquing angles up, and I'll torque them out in a minute.

193:51:26 Allen: Standing by.

[Comm break.]
193:53:17 Irwin (onboard): I'll get out of your way, Al, so you can get down in here.

193:53:33 Worden (onboard): Okay.

[Al calls up three angles on the DSKY (Display and Keyboard) to allow Mission Control to make a note of them. They are the angles by which the three gimbals supporting the guidance platform must be rotated to restore perfect alignment.]
193:53:39 Allen: Al, we - we've noted the termination of your fuel cell 3 purge. At your convenience, open the X-ray and the Alpha Particle experiment covers, please, and turn the Alpha Particle back on. Over.

193:53:54 Worden: Okay, Joe. We'll be about another 2 or 3 minutes finishing up all the dumps, and then we'll do that.

193:54:00 Allen: Okay. Fine. We do want you to wait until all the dumps are completed, and then open the doors and turn Alpha Particle on at your convenience, really.

193:54:11 Worden: Roger.

[Comm break.]
193:54:17 Scott (onboard): ... this morning.

193:54:19 Irwin (onboard): Yes, Myrtle. I didn't use - I didn't - hadn't used Myrtle this morning. I didn't use Myrtle this morning.

193:54:25 Scott (onboard): I think that checklist is ... 5 minutes and then closed.

193:54:29 Irwin (onboard): Yes, it does.

193:54:30 Scott (onboard): Yes, that's ... Yes. Yes. ...

193:54:36 Irwin (onboard): Yes. Yes. I didn't use that this morning.

193:54:40 Scott (onboard): ... Al. ...

193:54:50 Irwin (onboard): That's true.

193:54:51 Scott (onboard): ...

193:54:56 Irwin (onboard): Yes. You were smart.

193:55:20 Allen: Good ship Endeavour, this is Houston. We'll see you on the other side.

193:55:26 Worden: Okay, Joe.

[Very long comm break.]
193:55:43 Irwin (onboard): Okay, we got...

193:55:44 Scott (onboard): We stow this in that Jura [?] bag down there? When I took that ..., Al? Okay. Public Affairs Officer - "This is Apollo Control at 193 hours, 56 minutes. We've had Loss Of Signal on this revolution. Endeavour and its crew performing orbital science throughout the day. We passed up an update to the Flight Plan for today. Crew [were] reporting 9 hours of sleep last night and no medication. ... We'll reacquire Endeavour again at 194 hours, 41 minutes, about 30 seconds on its 60th revolution. At 193 hours, 57 minutes; this is Mission Control, Houston."

[Flight Plan page 3-306.]
193:56:28 Irwin (onboard): How about this? Go Manual and Wide. Right, Al? That what you say? Then - then go to Reacq? Just leave it in Manual and Wide until we come around, right?

193:56:41 Worden (onboard): What?

193:56:42 Irwin (onboard): Manual and Wide. How about the Squelch Enable?

193:56:56 Irwin (onboard): I have the Squelch Enable on.

193:59:17 Irwin (onboard): I'll get it. This is...

194:00:04 Worden (onboard): Okay.

194:00:20 Irwin (onboard): Okay, all ... be done behind here.

194:01:02 Scott (onboard): You want to - I don't care. Where is the best place for you to be?

194:01:08 Worden (onboard): Here ...

194:01:09 Scott (onboard): Okay. I'll just stay here in the center.

194:01:20 Worden (onboard): ...

194:01:22 Scott (onboard): I know. You ... put mine on.

194:01:25 Worden (onboard): ... launch.

194:01:27 Irwin (onboard): We might have them sorted out by then.

194:01:36 Scott (onboard): Old Al, he's a gentleman ...

194:01:40 Irwin (onboard): No, don't bruise him.

194:01:53 Irwin (onboard): Yes?

194:02:43 Scott (onboard): ... read that ... now?

194:03:05 Scott (onboard): ... Magic Marker ... Besides, these used to be the guys ... all versions ... all the cross-subjects of the Command Module. Although ... all the stuff ...

194:03:43 Scott (onboard): ... a lot of garbage. ...

194:03:55 Scott (onboard): ..., Jim .... all garbage ...

194:04:08 Irwin (onboard): Yes. ... put the garbage in here all ...

194:04:46 Scott (onboard): I don't...

194:04:49 Irwin (onboard): We do? Shoot, I - I feel great today.

194:04:56 Scott (onboard): ... gone from one ... to the two.

194:04:59 Irwin (onboard): What do I have to do?

194:05:01 Scott (onboard): Photograph that ...

194:05:02 Irwin (onboard): Oh, yes.

194:05:12 Irwin (onboard): I should have brought that LEC hook back. It sure was handy in the LM. Trying to grab stuff with the EV gloves was like work.

194:05:37 Scott (onboard): ... 5 minutes ... did you get them - did you get them back ...

194:05:49 Irwin (onboard): You know, Dave, we had probably - we had the worst condition possible for getting up and down that front ladders. That's the problem...

194:05:55 Scott (onboard): ...

194:05:56 Irwin (onboard): For getting up and down that front ladders. The gear hadn't stroked at all. And it was, you know, practically off the surface. If I didn't have anything, if I could give a good leap, I could make it to the first rung. Most times, while carrying something, I ended pulling myself up with my arms to get to the first rung.

194:06:15 Worden (onboard): ... the gear didn't stroke ...

194:06:16 Irwin (onboard): Didn't stroke at all. In fact, the front pad wasn't even on the surface. No, the pad was loose...

194:06:24 Worden (onboard): Yes.

194:06:25 Irwin (onboard): ...free to rotate, so it wasn't even - it wasn't making a firm contact at all with the surface.

194:06:36 Scott (onboard): ... sticking to the bottom, to me. I'll tell you, Jim, it sure is a lot easier than that damn ...

194:06:45 Irwin (onboard): Oh, yes, particularly, you know, if there is a little time. I - I could transfer the bags up and just leave them on the porch, wait for you to get up there, and you pass them, then I could grab them with that LEC hook.

194:06:55 Scott (onboard): ... in three times to try it. ... once to transfer the LEC ...

194:07:02 Irwin (onboard): Yes.

194:07:48 Worden (onboard): Try your scissors. You ... Your scissors are over there, on your left of your - O2 Flow, Hi. Help me dump it.

194:08:07 Scott (onboard): Oh, shit! ... ketchup ...

194:08:13 Irwin (onboard): Here's some, Dave. Right here.

194:08:15 Scott (onboard): Okay. Now ...

194:08:36 Irwin (onboard): Want some more?

194:08:39 Scott (onboard): ...

194:09:20 Scott (onboard): ...

194:09:42 Irwin (onboard): Cabin pressure's are ...

194:09:44 Scott (onboard): Cabin pressure's are what?

194:09:45 Irwin (onboard): Split at 5.

194:09:51 Scott (onboard): What? This vent is open ...

194:10:05 Scott (onboard): Myrtle was ... and the ... valve was just open ... back up.

194:10:50 Irwin (onboard): ... your burn's out if you leave your flow valve in normal? ...

194:11:15 Scott (onboard): Jim, I think this little valve in your Jiminy [?] bag is all clogged up. That's your problem. Because I just tried that, and it works fine - transferred to a new Jiminy [?] bag. ... valve.

194:11:26 Irwin (onboard): Yes, I think my valve is probably a little clogged.

194:11:28 Scott (onboard): Well, you got to keep it clean.

194:11:29 Irwin (onboard): Yes.

194:11:59 Scott (onboard): ...

194:12:02 Irwin (onboard): ... I don't think any ... in there.

194:12:58 Irwin (onboard): Anyone for chewing gum this morning?

194:13:53 Irwin (onboard): Want some chewing gum, Dave?

194:13:55 Scott (onboard): What?

194:13:56 Irwin (onboard): Want any chewing gum?

194:13:57 Scott (onboard): ...

194:14:37 Irwin (onboard): Do you have all the parts there, Al?

194:14:38 Worden (onboard): They're in here if you need them. ...

194:14:47 Irwin (onboard): Good.

194:14:56 Irwin (onboard): They go on here ... Take a whole piece.

194:15:24 Irwin (onboard): ...

194:15:39 Irwin (onboard): ... stuff like that.

194:15:53 Irwin (onboard): ...

194:16:16 Irwin (onboard): Watch it. This washer over here slipped.

194:16:33 Irwin (onboard): If you had a screwdriver, I think we could push the washer on this side down a little bit, Al. This washer here's slipped up.

[Endeavour's 60th orbit of the Moon begins at about 194:18 GET.]
194:18:37 Irwin (onboard): Okay. I've got it through now.

194:18:40 Worden (onboard): You've got it a little apart.

194:18:44 Irwin (onboard): ...

194:18:46 Worden (onboard): Where is the other part? I got it through the washers. Go ahead. ... be tighter than that.

194:18:56 Irwin (onboard): Man!

194:19:10 Irwin (onboard): I don't see it. Okay. Tightened it up to some extent ... this screwdriver. Why don't we try them out.

194:19:42 Irwin (onboard): Tool E fit in this socket over here? It's too big?

194:20:05 Irwin (onboard): Yes?

194:20:06 Scott (onboard): ...

194:20:10 Irwin (onboard): Okay, I think we got it. O2 Flow, Hi again.

194:20:33 Irwin (onboard): I think you almost got it. You want me to try it ...

194:20:50 Worden (onboard): Better put some chewing gum on it; maybe some tape. That's what we need. Put some tape around it. That will keep it from backing off.

194:21:06 Irwin (onboard): Guess we ought to check those screens on the - on the hoses, too; they're probably - should be changed this morning.

194:21:23 Scott (onboard): ... get the vacuum cleaner, pull all the filters out, and we'll ...

194:21:38 Irwin (onboard): Okay.

194:21:39 Scott (onboard): ...Get the vacuum cleaner ... off, lay down every bag and ... everything before we leave. ... shoes ... stow away ... In the mean time, I'll go around and ... get it ... all the little bags we have and ... all the goodies from the LM, put them in that one camera bag ... bag, end ... And ... check. It would be nice to log all ... before we start taking...

194:22:26 Irwin (onboard): Yes.

194:22:27 Scott (onboard): ...Exactly what we're...

194:22:30 Irwin (onboard): Yes, okay. Okay, Dave. If you hand me the tape. I think this is about as tight as we'll get this.

194:22:42 Scott (onboard): I can't hear you.

194:22:43 Irwin (onboard): Little pieces of tape.

194:22:44 Scott (onboard): Tape?

194:22:45 Irwin (onboard): Yes.

194:22:59 Scott (onboard): How big?

194:23:01 Irwin (onboard): Oh, probably - 6 inches worth. Yes.

194:23:13 Irwin (onboard): Yes.

194:23:27 Irwin (onboard): Dave Scott taught me. Tape everything. Yes, I don't know what we would have done if we hadn't had the tape along. I might have been without comm on the surface.

194:23:53 Worden (onboard): Okay, I think your seat's fixed.

194:25:17 Irwin (onboard): You know what we can also do, Dave, is wet wipe the MAGs. Might be even better then - wet wipe them - get a towel - damp towel here - Just wipe them off.

194:25:27 Scott (onboard): Mags?

194:25:28 Irwin (onboard): Yes, rather than vacuuming.

194:25:29 Irwin (onboard): No vacuum ... wet wipe ... towel ...

194:25:36 Irwin (onboard): Procedure says to unstow them, vacuum, and then wet wipe. Yes.

194:25:41 Scott (onboard): ...

194:25:47 Irwin (onboard): Yes, I was just going ... LM Timeline.

194:26:01 Scott (onboard): I think I would follow the ...

194:26:06 Irwin (onboard): Yes.

194:26:07 Scott (onboard): You know why I vacuum ...

194:26:11 Irwin (onboard): Okay.

194:26:12 Scott (onboard): ...

194:26:16 Worden (onboard): Can't we use this little square?

194:26:17 Irwin (onboard): Yes. Yes.

194:26:18 Scott (onboard): Make sure you ...

194:26:20 Worden (onboard): Use those little square Jobbies, you mean - we have around. Yes.

194:26:24 Scott (onboard): And I think vacuuming would be easier to get in the cracks. And I certainly think that dirt will - dirt can get in the cracks ... Maybe wipe the surface clean. ... Okay. ...

194:27:31 Worden (onboard): Yes. Okay.

194:27:33 Scott (onboard): ...

194:27:52 Irwin (onboard): You don't have another bag we can put this - this trash in?

194:28:02 Scott (onboard): ...

194:28:04 Irwin (onboard): I was wondering if we had another big feed bag that was just about empty - the food locker, we could put this in there. Better than making two transfers.

194:28:39 Scott (onboard): ...

194:29:08 Irwin (onboard): ... CG

194:29:10 Scott (onboard): ...

194:29:21 Irwin (onboard): Well, where's the Jett bag? Let's put it in the Jett bag.

194:29:24 Scott (onboard): We can't use the Jett bag. If we do that you've got to get the ...

194:29:32 Irwin (onboard): Okay, okay.

194:29:34 Scott (onboard): Get your own C ...

194:29:35 Irwin (onboard): Okay.

194:29:58 Irwin (onboard): We don't put up with it.

194:30:17 Irwin (onboard): Do you want to take this down with you? Just transfer all the stuff up - out of that bag and into this one here, Al.

194:30:22 Worden (onboard): Yes.

194:30:28 Scott (onboard): ... We got Jett bag in 3 - 310B ... Turn around and look ...

194:30:46 Worden (onboard): ...

194:31:12 Scott (onboard): No, that's ... canister.

194:31:25 Scott (onboard): Hey, I got a mapping camera pad ...

194:31:31 Irwin (onboard): Yes.

194:31:33 Scott (onboard): ...?

194:31:35 Irwin (onboard): Which one do you want to get in? This one? Okay.

194:31:51 Irwin (onboard): I'll Just unplug here.

194:33:35 Worden (onboard): ...

194:33:37 Scott (onboard): What?

194:33:38 Worden (onboard): I got the LM Timeline ...

194:33:56 Irwin (onboard): Yes, I have.

194:33:57 Scott (onboard): ...

194:34:09 Scott (onboard): Yes.

194:34:10 Irwin (onboard): ... cooled things off, too, huh? Beat his ass, too.

194:34:15 Scott (onboard): No, I ...

194:34:18 Irwin (onboard): Oh, I don't know.

194:34:20 Scott (onboard): No, I ... something.

[Six minutes before AOS (Acquisition Of Signal), Endeavour passes across the terminator and into lunar day. In preparation for this, Al has extended the Mapping Camera out on its track ready to begin a period of mapping photography which will continue until they reach the opposite terminator.]

[This period of mapping photography was essentially postponed from this morning as the crew were allowed an extended rest. At this time, the deadband is changed from 5° to ½°.]

194:37:21 Scott (onboard): Daylight. Oh, okay. Sure will. ...

194:37:35 Worden (onboard): ...

194:38:41 Scott (onboard): You know, I figure we got almost exactly a 100 hours. As a matter of fact, this ent - this orbit entry, or - entry interface, is at - 291:30 - huh - 294:43. It is now 194 and some.

194:39:25 Irwin (onboard): Not as bad as ...

Public Affairs Officer - "This is Apollo Control at 194 hours, 40 minutes. We're less than a minute away from Acquisition Of Signal on Endeavour's 60th lunar revolution. We'll stand by for air/ground during this pass."

194:43:09 Allen: Hello, Endeavour. This is Houston. [No answer.]

194:44:24 Allen: Hello, Endeavour. This is Houston.

194:44:32 Worden: Hello, Houston; Endeavour. Loud and clear.

194:44:35 Allen: Roger, Al. I wanted to tell you that, except for a couple of minor changes, you'll shortly be back on the nominal Flight Plan. I do have a Pan Camera photo PAD to be copied into your Flight Plan at 195 plus 00 when you're ready.

194:44:55 Worden: Okay, Joe. Go ahead.

194:44:58 Allen: All righty. At 195 plus 00, Pan Camera Mode, Standby; Power, On; Stereo, Exposure, Normal. At 195:04:13, Pan Camera Mode, Operate. At 195:14:30, Pan Camera Mode, Standby. Pan Camera Mode, Mono, at 195 18 23; Pan Cam Self Test to Self Test. The talkback should be barber pole for 30 seconds and then gray. And after the talkback is gray, Pan Camera Self Test to Heater. At about 195 plus 21, Pan Camera Power, Off, on a cue from MSFN. At - at 195 plus 34 plus 50, Laser Altimeter, Off; Retract Map Camera; and Close Map Camera Cover, per steps 7 and 8, page S/1-39 in your checklist. Over.

194:47:38 Worden: Okay, Houston; understand. And I'll go through the whole thing here for you. At 195, Pan Camera Mode, Standby; Power, On; Stereo and Exposure, Normal. At 195:04:13, Mode to Operate. At 195:14:30, Mode, Standby, and Stereo to Mono. At 195:18:23, Self Test to Self Test, and barber pole for 30 seconds and then Self Test to Heaters. At 195:21:00, Pan Camera Power to Off on your cue. At 195:34:50, Laser Altimeter, Off; Retract the Mapping Camera, and close the covers per steps in checklist S/1-39.

194:48:39 Allen: Okay, Al. Right on. And could you verify for us, please, that the Alpha Particle Spectrometer has been turned on and that the X-ray and Alpha Particle covers are open. Over.

194:48:55 Worden: Okay, Joe. The covers are open. X-ray is On, and Alpha Particle coming On now.

194:49:02 Allen: Okay, thank you. And, Endeavour; we need Narrow Beam on the High Gain [Antenna], please.

194:49:16 Worden: Got it. [Pause.]

194:49:27 Allen: Okay, Al. Thank you.

194:49:33 Worden: Roger, Joe.

[Comm break.]
194:51:22 Worden: Houston, 15.

194:51:24 Allen: Go ahead, Al.

194:51:29 Worden: Joe, looking ahead a little bit in the Flight Plan, I see we've got gegenschein coming up on this rev. And I guess my question is do you want me to change the film in the - in the camera now? In other words, have we missed any picture taking with the - the - the Nikon that maybe we want to pick up with that mag before I offload that mag?

[Al is referring to the second, ultimately unsuccessful attempt to photograph the gegenschein, a patch of light believed to be caused by the scattering of sunlight off particles that have collected at one of the Lagrangian points. To do this, he uses the Nikon 35-mm camera with a f/1.2 55-mm lens and 6,000 ASA film.]
194:51:55 Allen: Al, I'll have an answer for you in just a minute on that. In the meantime, could you reverify that the covers on the X-ray and Alpha Particle are open, and we're getting some problems on that, and I guess the best thing to do would be - to just go to your checklist, page 1-33, and do that Cover, Open, couple of steps - which is listed "Number 1, Cover, Open"...

194:52:22 Worden: Okay, now, Joe. You're right. I don't know - I don't know where we got - got our wires crossed, but the covers were closed and they're now open.

194:52:31 Allen: Okay, no problem. Good. [Long pause.]

194:53:33 Allen: Al, on your question on the gegenschein experiment, we want you to go ahead and change the mag to Victor, just per the Flight Plan.

194:53:44 Worden: Okay, Joe. Thank you.

[Long comm break.]
194:57:42 Allen: Hello, Al. This is Houston.

194:57:51 Worden: Hello, Houston. This is Al.

194:57:54 Allen: Roger, babe. Requesting you - give us a Gainstep on the Gamma experiment up three clicks, please. And we're also wondering what mag you've taken off the Nikon to put mag Victor on. There's some confusion in our minds. I guess we thought Victor was already on there. Over.

194:58:18 Worden: Negative. Mag U was on there before, Joe, and I had just taken it off.

194:58:23 Allen: Okay, thank you, Al. That helps us. And once again, the Gainstep on the Gamma, up three clicks. And we're showing that now.

194:58:33 Worden: You've already got it.

194:58:34 Allen: Thank you.

[Long comm break.]

[Flight Plan page 3-307.]

195:02:11 Allen: Endeavour, this is Houston. Requesting Auto on the High Gain, please.

195:02:11 Worden: Auto it is. [Long pause.]

195:02:59 Allen: Endeavour...

195:04:00 Allen: Mark. 15 seconds to Pan Camera, Off - On, Pan Camera, On. Sorry.

195:04:06 Worden: Roger. Roger. Got you, Joe.

195:04:14 Allen: Pan Camera, On.

195:04:20 Worden: It's On.

[Long comm break.]
Public Affairs Officer - "This is Apollo Control at 195 hours, 6 minutes. Endeavour's present orbit: 67 by 51.9 nautical miles [124.1 by 96.1 kilometres]. The orbital period: 1 hour, 58 minutes, 38 seconds; and we're showing a weight of 36,310 pounds [16,470 kg]. Present altitude for Endeavour is 65.6 nautical miles [121.5 km], velocity 5,315 feet per second [1,565 m/s]."
[Readers should note that NASA habitually use the term "weight" although it was and is generally recognised to be erroneous in this context. The correct term is "mass". Mass refers to the quantity of matter within a particular body, be it atom, spacecraft or galaxy. Place a mass within a gravity field and it will experience a force pulling it towards the source of the field. On Earth, though many of our scales are calibrated in kilograms, the standard unit of mass, in truth they depend on measuring the force acting on the body. This force is what we know as weight and it will vary from place to place. In the free-fall condition that the spacecraft is in, it has no weight. It is weightless. However, it still has mass.]
195:14:04 Allen: Pan Camera to Standby in 30 seconds.

195:14:11 Worden: Roger, Joe. Thank you. [Long pause.]

195:14:31 Allen: Pan Camera to Standby.

195:14:38 Worden: Pan to Mono.

195:14:42 Allen: We copy, and thank you, Al. And I've got a UV photo PAD, a big one liner, when you're ready to copy that.

195:15:01 Worden: Okay, Joe. Go ahead.

195:15:02 Allen: Roger. This is for your PAD located at 196 plus 50. And it is T-start, 196:56:19.

195:15:21 Worden: Understand, Joe. UV photo PAD. T-start, 196:56:19.

195:15:28 Allen: Right on, Al. Thank you. [Long pause.]

195:16:01 Allen: Endeavour. 30 seconds to Self Test.

195:16:13 Worden: Roger.

195:16:27 Allen: Al, I gave a bad call. I was 30 seconds premature on that. Stand by.

195:16:35 Worden: Okay. Looks like you'll get two Self Tests, Joe.

195:17:06 Allen: Al, that's no problem. We'll take both of them, and I'll cue you for the next.

195:17:14 Worden: Okay. I'll give you a whole series of them if you want them.

195:17:27 Allen: Negative, Al.

195:17:54 Allen: 30 seconds to Self Test.

195:18:00 Worden: Roger. [Long pause.]

195:18:22 Allen: Mark. Self Test.

195:18:29 Worden: Roger.

[Comm break.]
195:20:00 Worden: Houston, 15. Pan Camera is in Heater Mode now.

195:20:04 Allen: Thank you, Al. [Long pause.]

195:20:19 Allen: Okay, Al, and on the Map Camera, Image Motion to barber pole, please.

195:20:28 Worden: Roger.

[Long comm break.]
Public Affairs Officer - "This is Apollo Control at 195 hours, 28 minutes. The flight controllers who are monitoring the data from the SIM bay, report that it looks good, and the status check indicates that all systems on Endeavour are normal. All temperatures [are] within limits. Displays and controls, instrumentation, power distribution and sequencing communications, guidance and control, crew systems, propulsion and power, all parameters normal. We have 25½ minutes remaining in this front side 60th revolution."

195:29:28 Allen: Hello, Endeavour, this is Houston.

195:29:35 Worden: Houston, Endeavour. Go ahead.

195:29:41 Allen: Roger, Al. I've got what they tell me is the last change to your Flight Plan to put you back on the nominal.

195:29:52 Worden: Okay, Joe; stand by just one.

195:29:54 Allen: Okay. No hurry.

[Comm break.]

[Al should begin getting ready for the gegenschein photography about now. The Nikon camera is installed in window 4, the right rendezvous window, and will therefore be looking along the spacecraft's longitudinal axis.]

195:31:00 Worden: Okay; Houston; 15. Go ahead with the Flight Plan update. [Pause.]

195:31:14 Allen: Okay, Al. The first change is at 195 plus 36 in your Flight Plan. And it is "Gamma-ray Boom, Deploy, talkback barber pole for about 2 minutes and 40 seconds, then gray, and then to Off. Center position." Over.

195:31:54 Worden: Roger, Joe. Understand. At 195:36:00, "Gamma-ray Beam - Boom, Deploy, talkback barber pole about 2 minutes, 40 seconds, then gray, and switch Off."

195:32:07 Allen: Okay, Al. That's good, and the next two items are deletes over at 196 plus 31. And that is, delete...

195:32:22 Worden: Okay, go ahead.

195:32:23 Allen: ...delete "Map Camera/Laser Experiment Covers," et cetera, and delete "Map Cam Track," et cetera, and at 196 plus 37, delete "Laser Altimeter, On." Over.

195:32:51 Worden: Roger; understand. At 196:30, delete the 2 lines dealing with the Mapping Camera, and at 196:37 delete the Laser Altimeter function.

195:33:12 Allen: Okay, Al, and you're now back on your Flight Plan except for the additional couple of Pan Camera bursts and a Map Camera pass, that you already have copied down. And while I've got you on the line here, I'd like for you to think back yesterday, and I've got a question to ask concerning your suit integrity check. We're trying to go through this and reconstruct exactly what had happened. And I guess what we need is a - a comment about your third suit integrity check. And, that one was the one you did just after the first LM jett had been scrubbed and you went around the back side and did a suit integrity check, and we're wondering if you can recall any of the details of that check for us? Over.

[Before jettisoning the Lunar Module yesterday, the crew had problems getting a good pressure integrity check on their suits and on the forward hatch.]
195:34:03 Scott: Okay, understand you're concerned about the second suit integrity check we did. The third one was okay. The suits were - held integrity fine, and we had an O2 flow of about .6 to .7. So, I guess you're talking about the second one, huh?

195:34:27 Gordon: Dave, we're talking about the one you did before the last one, whatever number you call that.

195:34:36 Scott: Yes, Dick, that - that was the one we recycled quickly onboard up here, and it was because we had one of the gloves that wasn't fastened on exactly right.

195:34:52 Allen: Roger, Al. Map Camera and Laser, Off, please.

195:35:02 Worden: Okay, Map Camera and Laser, Off. And, did you understand the comment on the suit integrity check?

195:35:10 Allen: Fine, Al. Thank you. That helps us a lot.

195:35:16 Worden: Okay.

[Long comm break.]
Public Affairs Officer - "This is Apollo Control at 195 hours, 36 minutes. That last bit of information was for the Environmental Control Systems officer [EECOM] on shift now, who wanted to reconstruct the events of the suit integrity checks yesterday. The - a bad glove on that bad glove connector prevented a good check on the one they were discussing. They, since that time, did get a good suit integrity check."

195:39:21 Allen: Pan Camera Power, Off, when convenient, please.

195:39:21 Worden: Okay, it's Off.

195:39:33 Allen: Roger.

[Very long comm break.]
195:51:15 Irwin (onboard): Roger.

195:51:16 Scott (onboard): Roger. Let's go back to P00.

195:51:19 Irwin (onboard): Mine, too. Is mine in work?

195:51:22 Scott (onboard): No (laughter). I got mine.

195:51:26 Irwin (onboard): Yes.

195:51:27 Worden (onboard): ... went that-a-way, huh? Okay. I got tape motion going, so I guess we might as well...

195:51:42 Irwin (onboard): We don't need those guys.

195:51:50 Scott (onboard): Oh - beautiful. Fine.

195:51:58 Worden (onboard): ... your private beverage.

195:52:03 Allen: Endeavour, this is Houston. You are coming up on LOS in about 2 minutes, and everything's looking just as slick as glass.

195:52:13 Worden: Okay, Joe; and, we're just sitting here in [the deep space] attitude, all set to dim the lights and do the gegenschein [photography].

195:52:21 Allen: Okay, Al; sounds like fun. Enjoy the back side, and see you in a few minutes. And if there's anything you need from us down here, just give a call.

195:52:30 Worden (onboard): (Laughter.)

195:52:35 Worden: Certainly, Joe.

195:52:36 Worden (onboard): (Laughter.)

195:52:38 Allen: Knew you would.

[Very long comm break.]
195:52:38 Scott (onboard): "Anything you need, give us a call."

195:52:42 Worden (onboard): (Laughter) Just like we're assigned right behind...

195:53:02 Worden (onboard): Better check our camera time here.

195:53:08 Scott (onboard): 153 even is where the Flight Plan calls us.

195:53:50 Worden (onboard): Go ahead.

195:53:52 Scott (onboard): Okay, in one minute, Al.

195:53:55 Worden (onboard): Yes. What frame time?

195:53:57 Irwin (onboard): One frame, the whole minute.

195:54:01 Worden (onboard): Yes.

Public Affairs Officer - "This is Apollo Control at 195 hours, 54 minutes. We've had Loss Of Signal on Endeavour. The photography of the lunar surface and orbital science being conducted throughout this revolution. Data from the science experiments coming in good. We'll acquire Endeavour on it's 61st revolution, at 196 hours, 39 minutes, 20 seconds. At 195 hours, 55 minutes; this is Mission Control, Houston."

[Endeavour has been maneuvered out of the orb-rate explanation attitude that had the SIM bay continually facing the Moon, to the Deep Space Measurement attitude which is defined with respect to the stars. The spacecraft's motions are given time to damp and Endeavour is allowed to pass into LOS where it is shielded by the Moon's mass from the light of both the Earth and the Sun. The Deep Space Measurement photographs provide a pair of control frames against which the gegenschein frames can be compared. With a 1-minute and a 3-minute exposure done, Endeavour is reoriented to face the Moulton, or L2 Lagrangian point.]

[Flight Plan page 3-308.]

[Once the camera is facing the Moulton point, another two frames are taken with 1-minute and 3-minute exposures. Unfortunately, pre-mission calculations of the attitude they should orient the spacecraft to were incorrect and the photography is unsuccessful. This period of photography should be complete by the time Endeavour commences its 61st revolution at about 196:15 GET.]

195:54:04 Scott (onboard): Ten seconds.

195:54:05 Worden (onboard): One in each hand. ... look all right? Okay?

195:54:19 Scott (onboard): Looks like we're 1 minute and 18 seconds down in the Flight Plan.

195:54:23 Worden (onboard): Bravo. I want to go get a star mark.

195:54:27 Scott (onboard): Okay.

195:54:31 Worden (onboard): Hey. Got coffee?

195:54:36 Irwin (onboard): Yes.

195:54:38 Worden (onboard): Yes ....

195:54:40 Scott (onboard): Okay, Jim, if you'll give us Free.

195:54:53 Worden (onboard): And turn the lights off down there.

195:55:19 Scott (onboard): Can't get used to it. We're getting free light out there.

195:56:04 Worden (onboard): Yes, that's some stuff, ain't it?

195:56:06 Scott (onboard): That's really bright.

195:56:22 Worden (onboard): Now we're trying the gegenschein, the midway point, and the Moulton point. But we got to do an attitude maneuver here in just a minute. In fact, in 3 minutes from now, to be precise, since we're getting a 3-minute exposure.

195:56:52 Worden (onboard): Yes, we're all right for that.

195:57:03 Worden (onboard): Here.

195:57:05 Scott (onboard): That's - that's in some bunch of ... anyway.

195:57:17 Scott (onboard): Well, you see the gegenschein?

195:57:21 Worden (onboard): Well, it should be straight ahead of us, Dave.

195:57:30 Scott (onboard): ...

195:57:36 Worden (onboard): No.

195:57:54 Scott (onboard): Well, I'm not sure. I think we ought to get ... I - I - Why don't you look - I think it would be...

195:58:00 Worden (onboard): No. If there is such a thing, there's a - there's a very definite branch off from the Milky Way. Floating almost to big B. Well, it's not long.

195:58:19 Scott (onboard): No - no, the big hairy one.

195:58:28 Worden (onboard): Yes, that's right. No, it's - it's a localized area, you know. But it would probably be in the shape of an oval. Well, anyway, that's the only thing - that's the only thing that came close to that, was that thing that looked like a branch off the Milky Way. Double or nothing.

195:59:34 Worden (onboard): Okay, turn the lights up there, Jim.

195:59:54 Worden (onboard): No. Okay, go to CMC, Auto. Okay, now we want to maneuver to another point there: Midpoint attitude, Flight Plan.

196:00:05 Irwin (onboard): Midpoint. I understand.

196:00:09 Worden (onboard): Okay, plus .6900.

196:00:14 Irwin (onboard): Let's see.

196:00:17 Worden (onboard): 51007 And minus 021.

196:00:35 Worden (onboard): No, 261.

196:00:46 Scott (onboard): Yes. Okay.

196:00:48 Irwin (onboard): ...

196:00:54 Worden (onboard): It's - it's in the ...

196:00:56 Irwin (onboard): Oh, Jesus!

196:00:58 Worden (onboard): ...

196:01:10 Irwin (onboard): Shouldn't laugh at me.

196:01:18 Worden (onboard): Give him my regards.

196:01:21 Scott (onboard): Now break down a little bit. Look, he'll stay crazy if you're acting crazy. Look, Al, he doesn't understand.

196:01:29 Worden (onboard): We're down in the time line. Getting slightly green, Jimmy, my boy?

196:01:34 Irwin (onboard): No.

196:02:00 Scott (onboard): I got to get it into Auto.

196:02:08 Worden (onboard): ... getting ...?

196:02:12 Irwin (onboard): Christ!

196:02:17 Worden (onboard): Yes, I know.

196:03:08 Scott (onboard): Now let the rate damp there for a second; hope it improves.

196:03:48 Scott (onboard): Okay, you're not losing face.

196:03:52 Worden (onboard): Yes. Right. Okay.

196:04:19 Worden (onboard): As I was saying...

196:04:22 Irwin (onboard): Ah, go to hell, MDC.

196:04:24 Worden (onboard): What's that time on the other one? Time on the DSKY?

196:04:45 Irwin (onboard): ...

196:05:37 Worden (onboard): Mm-hmm. Yes, I used them, too.

196:05:51 Worden (onboard): What elevation? Yes.

196:06:32 Worden (onboard): Yes, there's quite a few stars out there, aren't there?

196:06:35 Irwin (onboard): Christ! ... given you?

196:06:38 Worden (onboard): A little darker now. Let's see. There's my star right up over there. Yes, that's...

196:06:49 Irwin (onboard): ...

196:07:02 Scott (onboard): ...

196:07:38 Scott (onboard): Damn! You always seem to take it bad when you do an alinement.

196:07:45 Worden (onboard): Well, you can't be all crude and all. But that little - that - that little - that thing there is something. Might be another planet.

196:07:54 Scott (onboard): Why don't you ...?

196:07:56 Worden (onboard): Yes. Yes.

196:08:18 Scott (onboard): ...

196:08:28 Worden (onboard): Yes.

196:08:47 Irwin (onboard): ...

196:08:54 Worden (onboard): Yes, trying to move ... We've got another 5 minutes to go. Anyway, we've used...

196:09:02 Scott (onboard): Okay. Okay, Jim, lights up.

196:09:14 Worden (onboard): And we got a P20 coming then.

196:09:19 Scott (onboard): Yes, CMC, Auto. And this time we want maneuver to -

196:09:38 Worden (onboard): Yes. We have ...

196:09:46 Scott (onboard): We haven't ...

196:09:54 Irwin (onboard): ...

196:09:57 Worden (onboard): Well, got the housekeeping done.

196:10:02 Scott (onboard): We're not going to have a ...

196:10:09 Irwin (onboard): That's a shame. ...

196:10:25 Worden (onboard): I can't find...

196:10:26 Scott (onboard): Turn the lights down and look for a few minutes, if you want.

196:10:29 Worden (onboard): We don't have to stop for another 10 minutes yet.

196:10:33 Scott (onboard): So you can go to Attitude Hold there, Jim.

196:10:36 Worden (onboard): Or go to CMC, Auto.

196:10:48 Worden (onboard): Got it. Turn it down. Turn that damn thing down.

196:11:37 Worden (onboard): ...

196:11:39 Irwin (onboard): I want to look for a few minutes.

196:11:56 Irwin (onboard): God damn. Is it in there?

196:11:59 Worden (onboard): You can see something bright down in there.

196:12:27 Irwin (onboard): Al, could you move it?

196:12:29 Worden (onboard): No, it's ...

196:12:50 Worden (onboard): Yes.

196:12:59 Scott (onboard): ...

196:13:05 Irwin (onboard): No, can't see. I just can't see. ... lights wouldn't come down. It's a function of lighting.

196:13:22 Worden (onboard): No .... got ... something else.

196:13:26 Irwin (onboard): No, I really can't see anything, Dave. ...

196:13:28 Worden (onboard): Oh, shit. You're too easily impressed.

196:13:33 Irwin (onboard): No one thinks like me.

196:13:35 Worden (onboard): Yes. As a matter of fact, that's what I keep saying.

196:13:44 Irwin (onboard): Freak you.

196:13:45 Worden (onboard): That's not nice.

196:13:48 Scott (onboard): See if I can see that.

196:14 01 Scott (onboard): Oh, let me see. That's - that's too hard to see.

196:14:09 Worden (onboard): Okay.

196:14:15 Irwin (onboard): ...

196:14:17 Scott (onboard): They're not - they're not as bright as I thought they' d be, either.

196:14:20 Worden (onboard): They're not?

196:14:21 Irwin (onboard): Is that right?

196:14:22 Scott (onboard): Yes. They're not - they're not much brighter than they are on Earth. Okay, lights up. Camera's off?

196:14:42 Worden (onboard): No, the guy wants that - business here. Yes.

[With the gegenschein photography out of the way, Al return the spacecraft to the SIM bay attitude that has the pointy end of the CSM facing forward. This returns the science instruments to an appropriate attitude for sensing the lunar surface.]
196:15:50 Worden (onboard): Okay, Dave, will you put these back in B-2 for me, please?

196:16:30 Scott (onboard): Jim? Is that breaker off?

196:16:59 Scott (onboard): Yes, might as well call.

196:17:01 Worden (onboard): All right. I want to move these before I - ... Ow!

196:17:09 Scott (onboard): All right.

196:17:11 Worden (onboard): Too early.

196:17:28 Irwin (onboard): ...

196:17:45 Worden (onboard): ...

196:20:33 Worden (onboard): Yes.

196:20:45 Worden (onboard): Huh? Yes. Yes, I'm a person. Right here, Jim.

196:20:51 Scott (onboard): ...

196:20:52 Worden (onboard): Well, put the TV back in...

196:20:56 Scott (onboard): If you will, snap that one.

196:20:58 Worden (onboard): It kind of gets in the way of everything else. Let me stick it down here for now.

196:21:08 Irwin (onboard): Sure is fun with lots of people.

196:21:12 Worden (onboard): Stow them.

196:21:54 Scott (onboard): Put that one down here with mine.

196:22:11 Scott (onboard): What's that, Jim?

196:22:13 Irwin (onboard): Nol

196:22:14 Worden (onboard): Good. Very good.

196:22:17 Scott (onboard): Okay?

196:22:18 Worden (onboard): Yes. You got to - yes. We've already signed those, haven't we? We haven't signed these? It really doesn't make much difference, does it?

196:22:26 Scott (onboard): No.

196:22:27 Worden (onboard): We don't really have to sign them now I guess. We can do that anytime.

196:23:10 Worden (onboard): Yes, those - those covers would have been infinitely more valuable, I think.

196:23:17 Scott (onboard): Oh, well.

196:23:21 Worden (onboard): Maybe, Dave, it's Just as well we didn't.

196:23:27 Irwin (onboard): Okay.

196:23:30 Worden (onboard): Bastard.

196:23:35 Scott (onboard): ...

196:24:49 Scott (onboard): I've got one. Come down.

196:24:51 Worden (onboard): God damn. Is it - is it in there?

196:24:56 Scott (onboard): Oh, I've only been changing the' film; one in the LM and one in there. Come on down.

196:25:02 Worden (onboard): I'm going to have to go all the way back to the Moon to come on some of that.

196:25:06 Scott (onboard): (Laughter)

196:26:13 Scott (onboard): ...

196:26:21 Worden (onboard): Yes, very good .... that move.

196:26:30 Scott (onboard): ...?

196:26:31 Worden (onboard): Yes.

196:26:32 Scott (onboard): What? No more film.

196:26:36 Worden (onboard): What?

196:26:37 Scott (onboard): ... I need more film ... camera ...

196:26:39 Worden (onboard): Can you change it?

196:26:42 Scott (onboard): ...

196:26:45 Worden (onboard): Yes, but you know the way he is.

196:26:49 Irwin (onboard): Feel around here.

196:26:50 Worden (onboard): Yes, sir.

196:26:57 Scott (onboard): ...

196:27:04 Worden (onboard): Oh, no. But I don't think you are ....

196:27:10 Irwin (onboard): That's the reason. Yes, yes, yes.

196:27:20 Scott (onboard): ...

196:27:22 Worden (onboard): That doesn't take very long.

196:27:26 Irwin (onboard): Where you going?

196:27:30 Worden (onboard): This guy's got more pens somewhere, because I need one to keep track of the Flight Plan, too.

196:27:35 Irwin (onboard): Here's one.

196:27:54 Scott (onboard): ...,Al.

196:27:55 Worden (onboard): I got one.

196:28:25 Worden (onboard): Excuse me, Jim.

196:28:28 Irwin (onboard): Excuse me.

196:29:33 Irwin (onboard): Sure can.

196:29:57 Scott (onboard): ...

196:29:59 Worden (onboard): Yes. I got one. Yes.

196:30:01 Irwin (onboard): ... solution in color ...

196:30:19 Irwin (onboard): You got a mag that hasn't been used at all?

196:30:32 Scott (onboard): ...

196:30:37 Worden (onboard): Huh? Just as - it may be just as well. Tell me we don't have any.

196:30:43 Scott (onboard): We don't - we don't have any of that left.

196:32:10 Worden (onboard): Hey, gang, they don't have another eat period for 6 hours.

196:32:12 Scott (onboard): What?

196:32:13 Worden (onboard): There's not another eat period in the Flight Plan for 6 hours.

196:32:16 Scott (onboard): Six more hours? Jesus Christ!

196:32:21 Worden (onboard): That's right. And that's just before our sleepy time.

196:32:28 Scott (onboard): Six hours to bed.

196:32:43 Scott (onboard): Yes. I don't think we need the contingency anymore. We don't need that one. Or these. Or these.

196:33:21 Scott (onboard): Can I get that map you got over there?

196:33:24 Worden (onboard): Okay. Yes, got...

196:33:29 Scott (onboard): Two of them here. Have three.

196:33:41 Worden (onboard): Okay, David.

196:33:42 Scott (onboard): Most of these don't.

196:33:45 Worden (onboard): Yes. Got two fresh maps here. One's labeled CMP and the other is labeled nothing.

196:34:36 Worden (onboard): Well, we missed some spectacular terminator photos. Damn. You know, I was wondering. You want to get the terminator photos if still possible. That would have really been spectacular.

196:34:54 Scott (onboard): ...

196:34:55 Worden (onboard): Well, yes. The terminator's on the Flight Plan.

196:35:00 Scott (onboard): Yes.

196:35:56 Worden (onboard): Well, if we've got the film, by golly, I'd like to take a lot of terminator photos.

196:36:09 Scott (onboard): Yes.

196:36:10 Worden (onboard): No, that'd really be neat; take a bunch of terminators. And the setting should be the same regardless of where the terminator went.

196:36:18 Scott (onboard): ...

196:36:21 Worden (onboard): Yes.

196:36:22 Scott (onboard): ...

196:36:23 Worden (onboard): Boy. That one's - Look at that.

196:36:29 Scott (onboard): ...

196:36:44 Worden (onboard): Do you know how to change the settings from 250 to 500?

196:36:49 Scott (onboard): ...

196:36:57 Worden (onboard): No, I mean - I mean what the comparable settings are. Like f/5, 1/50th and all that.

196:37:04 Scott (onboard): ...

196:37:05 Worden (onboard): Yes.

196:37:07 Scott (onboard): ...

196:37:09 Worden (onboard): Terminator photos for the 250, they call out f/5.6 and 1/125th. And that's for the very-high-speed black and white. Yes. You don't have any left though, do you? No. Yes.

196:37:31 Scott (onboard): ...

196:37:35 Worden (onboard): No. No, that's not fast enough. That's all right. Listen, I got lots of brand R left. Use it.

196:37:59 Scott (onboard): ... something.

196:38:02 Worden (onboard): Yes.

196:38:16 Worden (onboard): Yes. It sure would be nice to get a - some pictures down into the bottom of ... bottom. ...

Public Affairs Officer - "This is Apollo Control at 196 hours, 39 minutes. Apollo 15 will be within range of Earth tracking stations in about 15 to 20 seconds. We'll stand by for first conversations."

196:40:25 Worden (onboard): Oh, deary.

196:40:34 Scott (onboard): The old Earth is real impressing down there. ... get some.

196:41:16 Scott (onboard): ...

196:41:19 Worden (onboard): Oh, boy! God, I guess. That thing was huge.

196:41:25 Irwin (onboard): ...

196:41:27 Worden (onboard): Never did, huh?

196:41:41 Scott (onboard): ... Never mind.

196:42:34 Worden: Houston, 15.

196:42:56 Allen: Endeavour, Houston.

196:43:01 Worden: Hello, Houston. Endeavour here.

196:43:05 Allen: Roger, Al. Copy. And I've got a TEI-64 PAD when you're ready.

196:43:19 Worden: Okay, just a minute. [Long pause.]

196:43:39 Worden: Okay, go ahead with the PAD.

196:43:41 Allen: Roger, Alfredo. SPS/G&N for a TEI-64; 36310; plus 0.61, plus 0.92; 204:08:11.62, plus 3011.0, minus 0019.6, plus 0048.8; 180, 102, 002. All the rest NA. Ullage: 4 jet, 12 second. Over.

[An interpretation of the PAD follows:

Purpose: This is another abort PAD for an early return to Earth, with an ignition time right at the end of the 64th orbit around the Moon. Systems: The burn would use the SPS engine under the control of the Guidance & Navigation System.

CSM Weight (Noun 47): 36,310 pounds (16,470 kg).

Pitch and yaw trim (Noun 48): 0.61° and 0.92°.

Time of ignition, Tig (Noun 33): 204 hours, 8 minutes, 11.62 seconds.

Change in velocity (Noun 81), fps (m/s): x, +3,011.0 (+917.8); y, -19.6 (-6.0); z, +48.8 (+14.9). These velocity components are expressed with respect to the local vertical/local horizontal frame of reference.

Spacecraft attitude: Roll, 180°; Pitch, 102°; Yaw, 2°. The spacecraft attitude for the burn is expressed relative to the lift-off REFSMMAT.

SPS propellants are settled in their tanks by firing the plus-X thrusters on all four quads around the Service Module for 12 seconds.]

196:44:41 Worden: Roger, Joe. Understand TEI-64, SPS/G&N; 36310; plus 0.61, plus 0.92; 204:08:11.62; plus 3011.0, minus 0019.6, plus 0048.8; 180, 102, 002. The rest is NA. Four jet, 12 seconds.

196:45:11 Allen: Readback's correct, Al. Thank you.

[Very long comm break.]

[In the meantime, Al should be configuring the Hasselblad EL camera to take a series of images of the lunar maria in ultraviolet light. However, according to the Apollo 15 Index of 70-mm Photographs, no UV photos are taken until the next planned opportunity at 201 hours GET. Yet, the same index ascribes a large amount of photography to this orbit, using the 500-mm lens onto black and white film, and the 250-mm lens onto colour film.]

[The first sequence of photographs on the black and white magazine, mag QQ, are five images taken under high sun conditions of two linear features which run southeast to northwest across the northeastern side of Mare Tranquillitatis. AS15-81-10869 is the first of three images which show Rima Cauchy, a 210-km long rille similar in cross-section to Rima Hadley. The final pair from this area, of which AS15-81-10873 is the best, show the end of Rupes Cauchy, a fault type scarp which runs parallel to and about 50 km south of Rima Cauchy. This fault is about 120 km long and becomes a rille before terminating in the two craters shown in the photograph. The rille and scarp are named after a 12.4-km crater, Cauchy which lies between them, itself named after a French mathematician, Augustin L. Cauchy, 1789-1857.]

[AS15-81-10874 to 10883 are a sequence of ten shots looking at features around the southwestern rim of Mare Serenitatis, just northwest of the crater Sulpicius Gallus. AS15-81-10874 and 10879 are of a bright, diminutive unnamed crater with a classic ray pattern which lies beside the Montes Haemus range. AS15-81-10876, 10881 and AS15-81-10883 are of nearby crater which has a less well-developed ray system though a tongue of dark material is splayed out to one side. This is in an area that, like the valleys at Taurus-Littrow, is noted for the presence of dark mantling. Two touching rilles from the Rimae Sulpicius system are well shown in AS15-81-10877 and AS15-81-10882]

[AS15-81-10884 and 10888 look down into the 10.6-km crater Aratus, a simple bowl-shaped crater with a flat floor and slumped walls. The sequence of photos between and after these two show the landing site, then follow Rima Hadley upstream to its source. AS15-81-10885 and AS15-81-10892 show the plain of Palus Putredinus on either side of Rima Hadley. 10893 to 10897 show the course of the rille to Bela, an arcuate cleft that appears to be the source of the flowing lavas which cut the rille. The ejecta blanket of crater Hadley C, seen in AS15-81-10894, interrupts the path of Hadley Rille by its more recent formation. AS15-81-10899 shows part of the 10-km long Bela with Rima Hadley flowing from it at the top right of the image. To show the full extent of Rima Hadley, from Bela to the landing site, seven of these images have been composited, though readers should note that this is a large image exceeding 1,500 by 1,600 pixels.]

[As Endeavour sweeps out over mare Imbrium, two images, AS15-81-10904 and AS15-81-10905, are taken of one of the most prominent sections of Rimae Archimedes, 100 km southeast of the great crater itself.]

Public Affairs Officer - "This is Apollo Control at 196 hours, 55 minutes. In addition to the Scientific Instrument Module experiments being performed on this pass, the crew will perform the light flash experiment again, and we'll be taking some science visuals. These are observations of selected points on the Moon, visual observations of topographic features. In effect, orbital geology by observation. And the backup crew commander astronaut Dick Gordon has joined Joe Allen at the CapCom console."

196:58:46 Allen: Endeavour, Houston.

196:58:52 Worden: Hello, Houston; Endeavour. Go ahead.

196:58:54 Allen: Al, could you give us the Mass Spec. Discriminator switch to Low, please.

196:59:03 Worden: Mass Spec. Discriminator to Low.

196:59:05 Allen: Okay, thank you. And did you get a volunteer for [the] eye flash experiment?

196:59:15 Worden: Yes, I think we have a volunteer for you.

196:59:21 Allen: Okay.

196:59:22 Irwin: Your volunteer is checking in here, Joe.

[On three occasions throughout the flight, time is set aside for the analysis of flashes seen within the eye by many lunar travellers. See the journal covering the first light flash experiment in section 7 of the Apollo 15 Flight Journal - Day 3: Flashing Lights; and again starting at 264:26:15 GET for the third light flash experiment in section 23, Science and a Press Conference for accounts of the other two experimental periods. The flashes are believed to be caused by high energy cosmic rays passing through the spacecraft and impinging on the eyeball.]
196:59:24 Allen: Okay, Jim. A quick word on it. Everything per the Flight Plan. We are going to ask you to go ahead and give us your description real-time on the downlink and your choice if you want to push-to-talk or go on to VOX. And then, when you go around the corner you can put it on the DSE like you did before, in High Bit Rate.
[On the first occasion, the crew had wanted to use the voice track of the DSE (Data Storage Equipment) to verbally record the characteristics of each flash, giving only a verbal mark on the air/ground comm. As the transcript of this is not in the record, their idea may not have worked although the air/ground information was recovered.]
Allen (continued): And Al, we got a one-time-special good deal for you in the meantime. We're coming up - you're going to be flying over the LM impact point shortly, where your trusty Falcon augered into the Moon, and we're going to ask for a short Pan Camera burst there. We'll come up with that photo PAD to you in a minute. In the meantime, at your convenience, could you go to Free, load Noun 79 to .5 deadband and - then go back, please.
[Program 20 is controlling the attitude of the spacecraft at the moment with a 5° deadband. Whenever they wish to narrow the deadband, they place the computer mode switch to Free whereby it is no longer driving the RCS, then they enter the figure for the revised size of the deadband before returning the spacecraft's attitude to computer control. This procedure may be to force the computer routines to start from scratch. A deadband of 0.5° is used whenever the SIM bay cameras are operating to ensure accurate pointing.]

[Flight Plan page 3-309.]

197:00:22 Worden: Okay, we'll do that, Joe. Stand by. That ought to be good.

197:00:40 Allen: And, Endeavour, you will be interested to know that the impact of Falcon was picked up on three beautiful seismometers on the Moon - a really remarkable record.

197:00:53 Worden: Which ones were they, Joe?

197:00:55 Allen: Apparently, they were the ones from Apollo 12, Apollo 14, and Apollo 15. We haven't had reports from other seismometers yet.

197:01:09 Worden: That's very interesting.

[Of course, there are only three working seismometers on the Moon at this time and well Al knows it.]
197:01:14 Worden: Tell us, Joe, did they get the LM impact close to where they wanted it?

197:01:23 Allen: Roger. It went in to within about a degree and in fact, as you know, it doesn't - the exact point isn't all that important. It - it went in just about where we wanted it, though.

197:01:45 Allen: And Al, as soon as you have Noun 79 and you give us Accept, we'll give you state vector. Over.

197:01:57 Worden: Okay, Joe. You have it.

197:01:58 Allen: Roger. We see it. Thank you.

197:02:04 Irwin: Okay, Joe, I'm ready to start the - experiment.

197:02:09 Allen: Okay, Jim, we're copying.

197:02:15 Irwin: Okay. [Long pause.]

197:03:01 Allen: Endeavour, Auto on High Gain, please.

197:03:08 Irwin: Roger. Auto.

[Comm break.]
197:04:48 Allen: Al, this is Houston. You can go back into Block. We still need a half a degree deadband. And you can delete two lines in your Flight Plan, one at 197:04 and one at 197:09, both the "Pan Camera" lines there, delete them. Over.

197:05:12 Worden: Roger, Joe. Understand. Delete the "Pan Camera" lines at 197:04 and 197:09.

197:05:19 Allen: Roger. You can Block the computer but we need a half a degree deadband.

197:05:29 Worden: Roger, Joe. I've loaded it a couple of times. Let me check it again. [Long pause.]

197:06:08 Worden: Okay, Joe. I've got half a degree and - guess I'm having a hard time counting today.

197:06:13 Allen: Thank you, Al. I'm not doing any better.

197:06:18 Worden: Roger.

[Comm break.]

[What Al is actually entering are five digits into the second register of Noun 79. This early computer software is written without routines to handle the decimal point. Therefore, the computer assumes that values are properly scaled before they are entered. The value Al is entering always represents the deadband in hundredths of a degree and he does not enter a decimal point. The difference between entering a 5° and a 0.5° figure is 00500 versus 00050 and it is likely Al simply placed the "5" in the wrong place.]

197:08:27 Irwin: Joe, are you still there?

197:08:31 Allen: Go ahead.

197:08:36 Irwin: As long I'm lying here waiting for a flash, I might comment that Dave and I both observed the flashes while we were - on the surface. While we were in the bunks down there, we observed the flashes with the - oh, about the same frequency as we observed in orbit. One night there was about a 5-, 10-minute period there where I was awake, and I ran a little experiment by just turning over in the bunk. It seemed like the frequency was much less when I was lying on my stomach as opposed to lying on my back. It's just a note of interest.

197:09:18 Allen: Okay, Jim. That's a most interesting comment. And as you know, with about 10 minutes to go during the experiment today, we'll ask for you to turn over and be oriented with your face away from the Moon, and we might very well get the same sort of information this time.

[If the Moon acts as a shield, it would be expected that the radiation causing the flashes would preferentially arrive from one side of the spacecraft when in close lunar orbit. By placing the eyes between the head and the Moon, the head would also act like a shield and further reduce the number of flashes seen. If so, then the frequency of flashes would be expected to increase when Jim turns to face away from the Moon.]
Allen (continued): Al, I've got a photo PAD for you to copy when you're ready. And then, Jim, you can just go ahead and switch to VOX mode, if you don't want to push your push-to-talk [switch] while you transmit to us. Your choice on that, though.
[In VOX mode, a voice-operated switch automatically transmits when Jim talks.]
197:09:55 Irwin: Okay, no problem.

197:09:57 Worden: Okay, Joe. Go with the PAD.

197:10:00 Allen: Roger. Pan Camera PAD at 197 plus 16 plus 22. And you're to go to Operate per step 5 in your checklist, page S/1-38. And at 197 plus 18 plus 22, the Pan Camera to Standby. And at 197 plus 40, you can delete the P52 scheduled then. Over.

197:10:53 Worden: Roger, Joe. Understand. You want the Pan Camera to - to Operate at 197:16:22 as per the system's checklist 1-38 and to Standby at 197:18:22. And delete the P52 at 197:44 - or - 40.

197:11:13 Allen: Right on, Al. Thank you. And, Jim, we're standing by to copy your comments.

197:11:23 Irwin: Roger, Joe.

197:12:01 Allen: And, Jim, this is Houston. We'd like for you to transmit your description as well as the mark call, please.

197:12:04 Irwin: Understand. [Long pause.]

197:12:39 Irwin: Mark. And it was at the left eye; 8 o'clock, and it was a streak, and it seemed to be moving from 8 o'clock to maybe the 1 o'clock position, about - it covered about 20 degrees of arc out to a position - periphery at 8 o'clock into midway on our sphere of reference. An intensity of three. And...

197:13:13 Irwin: Mark. I just had a flash at 1 o'clock, moving to the center - the center of - moving toward the 12 o'clock position. It was intensity 3 and that last one was the right eye.

197:16:13 Irwin: Mark. A flash at the 12 o'clock, intensity 4.

197:16:25 Irwin: That was right down the plus-X axis, Joe. [Pause.]

[Endeavour is approaching the site where Falcon finally impacted and the Panoramic Camera is taking two minutes worth of pictures.]
197:16:42 Allen: Roger, Jim. Copy. [Long pause.]

197:17:07 Irwin: Mark. A flash at the 8 o'clock, left eye, periphery, intensity 2. [Long pause.]

197:17:38 Allen: Al, Pan Camera Stereo switch to Stereo, please.

197:17:46 Worden: Okay, Stereo it is. [Long pause.]

197:18:28 Worden: And Pan Camera to Standby.

197:18:37 Allen: Okay, Al. Thank you. That might be a super picture.

197:18:28 Worden: Sure hope so, Joe.

[Long comm break.]
Public Affairs Officer - "Jim Irwin is facing the lunar surface during the first part of this experiment."

197:24:11 Allen: Jim, this is Houston. How are the eye flashes coming?

197:24:17 Irwin: Still waiting, Joe.

197:24:20 Allen: Okay.

[Comm break.]
197:26:54 Irwin: Mark. A first ray of flash, 10 o'clock, left eye, about three quarters of the way out to the periphery, intensity 5.

197:27:17 Irwin: Mark. A streak, at 1 o'clock, moving from the bottom to the top of the - our sphere. Moving - moving definitely vertically up, beginning at 1 o'clock, about three quarters of the way up - intensity 2. [Long pause.]

197:29:58 Allen: Jim, this is Houston. And we're still listening to you. In the meantime, I've got a Map Camera PAD to give to Al when he's ready. Over.

197:30:10 Irwin: Okay, he'll be with you shortly.

197:30:13 Worden: Yeah. Hold on, Joe. We're going over the Harbinger Mountains and right over the Aristarchus Plateau right now. And Dave and I are looking like mad and taking pictures.

[They have good reason to be concentrating on this region as it is one of the most spectacular on the Moon and one to which they will return later in the mission. Aristarchus itself is perhaps the brightest large crater on the near side and is visible with the naked eye, even in the gloom of Earthshine. It was formed about half a billion years ago on a large plateau that is the source of a great many sinuous rilles, large and small. These were cut by flowing lava in much the same way as Hadley Rille was formed, when they fed the expanse of Oceanus Procellarum surrounding the plateau. Often these rilles begin in crater-like bowl-shaped depressions, including the largest, Vallis Schröteri or Schröter's Valley. The landscape around Aristarchus is probably more than six times older than the crater itself.]

[The sequence of photographs that Dave and Al are taking begins with AS15-96-13042. It and AS15-96-13043 are of Rimae Prinz, two rilles just east of the westernmost outcrop of Montes Harbinger. One of these rilles is bisected by an extraordinary depression somewhat like an elongated stadium. This may be a pre-existing crater chain which was flooded by the lavas delivered by the rille. AS15-96-13044 and 13045 show the north rim of the flooded crater Prinz, named after Wilhelm Prinz, 1857-1910, a German selenographer. A small crater just behind that rim, Vera, is the source of another sinuous rille which runs west then north from Prinz. Vera is an example of the many small craters on the Moon that have been assigned arbitrary male or female forenames rather than the more usual name of a deceased scientist. AS15-96-13046 to 13049 have been composited to show the continuation of the rille from Vera until it fades out past the small crater Krieger C. A wider context of these features is given in one of the frames from the Mapping Camera, AS15-2606M]

[AS15-96-13050 is an oblique image of Aristarchus looking roughly north. Note the texture of the surrounding ejecta blanket and how it covers the southern basalt plain in the foreground indicating that the crater is younger than the mare. The terracing or slumping of the wall of this spectacular 40-km diameter, 3-km-deep feature is also well shown. The crater's name comes from the Greek astronomer, Aristarchus of Samos, c. 310-230 B.C.E., who is notable for professing that the Earth rotates on its axis and that it revolves around the Sun.]

[Northwest of Aristarchus, the mighty Vallis Schröteri meanders towards Oceanus Procellarum. The lighting is still too oblique to show much detail although its entire length is photographed in AS15-96-13051 to 13062. The first of this sequence, 13051, shows the source of the rille, the "Cobra's Head", and AS15-96-13052 betrays the existence of an inner rille which loops along the floor of the main feature. A frame from the Mapping Camera, AS15-2610M, shows the rille's course and the crew will photograph it later in the mission once the Sun has risen higher.]

[Scott, from the 1971 Technical Debrief - "I thought the view was spectacular. Every time we came around the corner and had another chance to look at the surface, I saw something entirely new and different."]

[Worden, from the 1971 Technical Debrief - "It was interesting too, from my standpoint. I'd been there for quite a while just looking at the surface go by while you were on the surface. I did the plane change [burn] at 6 hours before rendezvous, and I never had a chance to look at the ground track from the time I did the plane change until after we all got together in the Command Module. It was completely new terrain to me, too (because of the Moon's rotation moving their ground track). We were all sitting there looking at something very new."]

[Scott from the 1971 Technical Debrief - "The terminator is the most interesting part, by far. You can see so much. It is just spectacular. I saw something at Hadley as we went over that was surprising. It's a continuation of the rille into the mountains. As you looked out, it was quite obvious that Hadley Rille was much longer than we had thought before the flight, from the Orbiter photos and the maps. It goes right into the mountains."]

197:30:23 Allen: Fine, Alfredo. When you get back to me, I'll give you this other PAD. It's got to be within the next 15 minutes though.

197:30:34 Worden: Okay, Joe. No problem, we're about done.

[Comm break.]
197:32:16 Irwin: Mark. Flash at, seems like it was in both eyes, at about the 7 o'clock position, one quarter of the way out the periphery, intensity 5. [Long pause.]

197:33:23 Worden: Houston, 15. Ready to copy the PAD.

197:33:30 Allen: Roger, Al. At 198 plus 25, go to narrow deadband in P20; Verb 22, Noun 79, plus 000.50. Open Cover and Extend Map Camera, per steps 3 and 4 in your checklist. 198 plus 31, Map Camera Image Motion, On. 198 plus 32 plus 10, Map Camera, On; Image Motion, increase, barber pole plus 4 steps; Laser Altimeter, On. 199 plus 19, Image Motion, increase, talkback barber pole. 199 plus 31 plus 56, Map Camera, Off; Laser Altimeter, Off; wait 30 seconds then Map Camera, On - That - that should read, Map Camera, On, to Standby; and then Retract and Close Cover, per steps 7 and 8 in the checklist. And that brings you to 199 plus 31 in your Flight Plan and you can delete the three lines at that point, "Map Camera Image Motion, On; Map Camera, On; Map Camera Image Motion, increase." Over.

197:36:00 Worden: Roger, Houston. Copy. At 198:15, go narrow deadband at P20. Open Mapping Camera Covers and Extend the Mapping Camera. At 198:31 plus 00, Mapping Camera, On. - Oh, I'm sorry, Image Motion, On. And 198 plus 32 plus 10, Mapping Camera, On; Image Motion to barber pole plus 4; and Laser Altimeter, ON. At 199:19:00, Image Motion to barber pole. At 199:31:56, Mapping Camera, Off; Laser, Off; wait 30 seconds, Mapping Camera to Standby - No, that's Retract and Close Covers.

197:36:55 Allen: That's correct, Al; and you can delete those three lines at 199 plus 30. And - there's a note that goes with this. This particular pass will be taken with the Gamma[-ray] experiment and the Mass Spec. experiment booms extended. So don't worry about the fact they're out. One number you gave to me, the first one, should be 198 plus 25, go to narrow deadband. Over.

197:37:28 Worden: Roger. 198:25. That's what I had written. [I] read it wrong.

197:37:32 Allen: Okay, thank you.

197:37:37 Irwin: Okay, Joe. During that conversation, I saw two - both at 8 o'clock. First one was three-quarters of the way out, intensity 2. The last one was at intensity 3, about halfway out, appeared to be at left eye.

197:37:54 Allen: Thank you, Jim; copied.

[Long comm break.]
197:44:15 Irwin: Mark. Flash at center, plus-X, intensity 2.
[Comm break.]
197:46:33 Irwin: Mark. Flash, left eye, 9 o'clock, on the periphery, intensity 5.

197:46:44 Allen: Roger. [Long pause.]

197:47:23 Scott (onboard): Well, we ought to be able to tell in an hour.

197:47:24 Irwin (onboard): Okay.

197:47:30 Scott (onboard): The what? Oh, yes. Okay?

197:47:30 Irwin: Joe, how is the time going on my one hour?

197:47:33 Allen: Okay, Jim. My sand dial shows about 15 minutes remaining. You'll be going around the corner LOS shortly. We don't have any more instructions for you on the experiment or in fact on anything else going on. We would like your present - a description of your present position in the spacecraft. And, we'd like for you to remain in that position for the rest of the 15 minutes in the experiment. Over.

197:47:55 Irwin (onboard): ...

197:47:57 Scott (onboard): We are, Jim. I got it hot for you. Don't worry, pal, we won't forget you.

197:48:05 Irwin (onboard): I'll bet you ...

197:48:04 Irwin: Okay, understand you don't want me to turn over.

197:48:09 Scott (onboard): No. I think he's right here.

Irwin (continued): I'm in the left couch and, of course, facing the plus - plus-X, and just when we started that conversation, I had a flash at 11 o'clock on the periphery, intensity 4, and then just the - at the end of your conversation, I had a streak moving from the 3 o'clock to the 9 o'clock, right to left. Right through the plus-X position.

[The Flight Plan instructions called for Jim to sit facing the Moon. He seems to have misinterpreted this as he is in the left couch and is facing towards the apex of the spacecraft, looking along its X-axis. In the current attitude, with the SIM bay facing the surface, this axis and the apex are pointing in the direction of travel, at right angles to the Moon's surface.]
197:48:15 Scott (onboard): Neuter? Okay, that spaghetti is mine. Hamburger wet pack. Pea soup, ham and salad, applesauce, cheese crackers. Brack!

197:48:32 Scott (onboard): Blach! Does it look like it, Jim?

197:48:34 Irwin (onboard): Yes.

197:48:36 Scott (onboard): You say it looks like it, Jim?

197:48:39 Irwin (onboard): No.

197:48:42 Allen: Okay, Jim, copied that and that's correct. Just - just stay in your present position, and we'll see you on the other side.

197:48:45 Worden (onboard): You got eyes, they're almost 20 - 20, so - (laughter) Okay, it's a...

197:48:52 Irwin: Okay.

[Very long comm break.]
197:48:53 Scott (onboard): I think it's time to raid you. I want to make sure they get it all down - down on the - on the file there.

197:50:26 Scott (onboard): Very good.

197:50:28 Irwin (onboard): What?

197:50:30 Scott (onboard): That one's for you. Here. Have at it. ... turn around ...

197:50:53 Worden (onboard): ... here.

Public Affairs Officer - "This is Apollo Control; 197 hours, 52 minutes. We've had Loss Of Signal on revolution number 61. Throughout this pass, the orbital science experiments have been conducted. Al Worden did Panoramic Camera photography of the Lunar Module impact point and Jim Irwin has been conducting the light flash experiment throughout most of the front side pass and will continue it as the spacecraft goes around behind the Moon. Our unofficial count of the flashes he marked while we were in contact comes to an even dozen. At 197 hours, 53 minutes; this is Mission Control, Houston."

[Flight Plan page 3-310.]
197:52:04 Scott (onboard): ...

197:52:09 Irwin (onboard): Well, I think I'd - stick it under the couch there. That's where I kept it before. But, of course - Huh?

197:52:17 Scott (onboard): ...

197:52:19 Worden (onboard): (Laughter)

197:52:21 Scott (onboard): ...

197:52:22 Irwin (onboard): May be, David. The empty ones, you mean. Oh, that's what you're talking about. Empty one. Yes. Yes. A-2.

197:52:37 Scott (onboard): Okay, Jimmy, you got 8 minutes to go.

197:52:59 Irwin (onboard): ...

197:53:01 Scott (onboard): Hey, listen. You - you - you're bugging me a little bit. If you're going - if you're going to exercise, you ought to at least have the decency to put your biomed on (laughter). There's no sense wasting all that on us. Let the doc see it.

197:53:23 Scott (onboard): Ooh, applesauce. Their applesauce is good stuff.

197:54:05 Irwin (onboard): You have Cannon towels, no doubt.

197:54:06 Worden (onboard): Yes.

197:54:07 Scott (onboard): I think I've been holding this many of them before.

197:55:31 Scott (onboard): Oh, yes. Yes, we were in darkness about the time ... We'll be on the dark side for about 20 minutes now.

197:58:06 Scott (onboard): Two minutes to go, Jim.

198:00:42 Worden (onboard): Hey, Jim.

198:00:46 Scott (onboard): Okay, Jim.

198:01:24 Worden (onboard): ... regular ... heartbeat.

198:01:34 Scott (onboard): Huh? Yes. After - after a while it gets to be working, moving your legs around again, you know?

198:01:45 Irwin (onboard): ...

198:01:53 Scott (onboard): ... boy, oh boy.

198:02:38 Scott (onboard): How do you mean?

198:02:48 Worden (onboard): No?

198:02:53 Scott (onboard): Oh, my eyes - my eyes were playing funny tricks on me for a while. ...?

198:02:58 Worden (onboard): So am I. Yes.

198:03:01 Scott (onboard): I'll think I'll see a - yes. Yes.

198:03:09 Irwin (onboard): Oh, yes, I seem to be getting them.

198:03:17 Scott (onboard): Well, that's like a ...

198:03:19 Irwin (onboard): Too early.

198:03:22 Scott (onboard): No. My brain is seeing them when you're not.

198:03:35 Worden (onboard): Hey, Dave, you any good at putting hot water in?

198:03:38 Scott (onboard): Oh, God, yes. Let's - Okay.

198:03:42 Worden (onboard): How about doing some pea soup for me when you get around to it?

198:03:45 Scott (onboard): Huh? Where's your spoon, Jimmy?

198:03:56 Worden (onboard): Is it in here?

198:04:12 Worden (onboard): ... Jimmy's spoon.

198:04:19 Irwin (onboard): It's in the - oh, okay. ...

198:04:32 Worden (onboard): You mean like these?

198:04:45 Worden (onboard): What spoon?

198:04:49 Scott (onboard): How many?

198:04:59 Worden (onboard): Oh! Gee, what'd I do? Try to get rid of them?

198:05:46 Scott (onboard): What?

198:05:55 Irwin (onboard): You're getting ... for a ...

198:05:57 Worden (onboard): Yes.

198:06:02 Scott (onboard): ...

198:06:35 Scott (onboard): ... (Clears throat)

198:06:46 Worden (onboard): Yes.

198:06:50 Irwin (onboard): ...

198:06:53 Worden (onboard): Watch it. He'll be bitching about that.

198:07:42 Irwin (onboard): ...

198:07:45 Worden (onboard): Yes.

198:07:50 Irwin (onboard): Give it to Al.

198:07:57 Worden (onboard): Give me the little white tool.

198:08:17 Worden (onboard): Thank you, Dave.

198:09:15 Worden (onboard): ... got in the way here.

198:09:18 Irwin (onboard): ...

198:09:21 Worden (onboard): Yes. It really is. Yes. I wish you guys would go somewhere.

198:09:45 Irwin (onboard): ...

198:09:47 Worden (onboard): Because he doesn't want the gray to show.

198:09:50 Irwin (onboard): ...

198:09:51 Worden (onboard): (Laughter) He'd be perfectly happy if we had pens instead of erasers.

198:10:15 Worden (onboard): (Laughter)

198:10:49 Irwin (onboard): ...

198:11:22 Scott (onboard): Hey, how about exporting it?

198:11:34 Scott (onboard): ... Yes ....

198:12:20 Worden (onboard): ...

198:12:43 Scott (onboard): You guys ...?

198:13:15 Irwin (onboard): ...

[At about 198:15 GET, Endeavour begins its 62nd orbit of the Moon. Soon after, Al reduces the deadband to ½° and begins the period of Mapping Camera photography just read up which begins as the spacecraft crosses the terminator into lunar day.]

[For half an hour, the crew have an exercise period then they continue with some handheld photography of features on the far side, though rather than following the targets suggested in the Flight Plan now, they elect to spread their picture-taking over this and the next orbit.]

[They have two Hasselblad cameras in use, one with black and white film and the long, 500-mm telephoto lens; the other has magazine O with colour film (Ektachrome) and a 250-mm medium telephoto lens. During a sequence of 19 images taken with the latter combination just before AOS, AS15-97-13175 to 13193, they photograph target number 10 as given in the Flight Plan, the ancient 130-km crater Sklodowska. Leading up to this are five images looking towards their northern horizon and across the crater Kondratyuk. With two smaller, but not insubstantial craters on either side of its floor, Kondratyuk straddles across the centre of AS15-97-13177. Before reaching their target, they take an excellent image of an unnamed crater in AS15-97-13180 sited southwest of crater Kovalsky.]

[The next 13 images, AS15-97-13181 to 13193 scan up to and across Sklodowska travelling in a SE-NW direction. Not far away from this feature is the slightly larger crater, Curie, which gives a hint of where the former got its name, for Sklodowska is the maiden name of Marie Curie, 1867-1934, the Polish physicist and chemist who twice won the Nobel prize, first in physics along with her husband Pierre for whom the other crater is named, and then in chemistry. The southeast rim of the crater is seen in AS15-97-13183 including a smaller bowl-shaped that punctures its wall, while AS15-97-13184 brings the double central peak into view. The far, northwest rim is shown in AS15-97-13187. Note the small crater just beyond the rim and the heavily slumped wall where the crater formed. Both these features are well displayed in AS15-97-13188 and it is easy to imagine that the slump could have been caused by the shock of the small crater's impact though this is unlikely judging by the aged appearance of the slump.]

198:20:30 Scott (onboard): ...

198:20:35 Worden (onboard): ..., Dave.

198:20:37 Scott (onboard): Where? I don't see ... Huh?

198:20:44 Worden (onboard): Right there.

198:20:46 Scott (onboard): ...

198:21:07 Scott (onboard): Yes. I can see ...

198:21:10 Worden (onboard): (Laughter)

198:33:34 Scott (onboard): Don't forget, we got...

198:33:37 Worden (onboard): Yes.

198:35:50 Irwin (onboard): What a sport.

198:36:06 Irwin (onboard): What a sport!

198:36:08 Worden (onboard): ...

198:36:09 Irwin (onboard): You are.

198:36:11 Worden (onboard): (Laughter) Yes. Yes.

198:36:29 Irwin (onboard): Enough!

198:36:32 Worden (onboard): Yes.

198:36:33 Scott (onboard): Enough's enough. ...

198:36:39 Irwin (onboard): Yes.

198:36:41 Scott (onboard): ...

Public Affairs Officer - "This is Apollo Control at 198 hours, 37 minutes. We should be acquiring Endeavour shortly on its 62nd revolution of the Moon. We'll stand by live during this pass."

198:41:15 Allen: Hello, Endeavour. This is Houston requesting Reacq and Narrow. [Long pause.]

198:41:50 Allen: Okay, Al, thank you very much. Some time during this pass, we are going to be requesting an ISA [Interim Stowage Assembly] weight which you have in your Lunar Surface Checklist, page 3-2. And we'll have a Map Camera and a Pan Camera PAD to send up to you.

[The ISA was used for stowage in the LM during Dave and Jim's stay on the surface and to carry items from the LM to the CSM.]
198:42:23 Worden: Okay, Joe. That all sounds very good. [Long pause.]

198:42:53 Allen: Endeavour, this is Houston. We're showing your Mapping Camera not on at this time and are requesting it on. It may be just to reverify from your 198 plus 32 plus 10 on the Flight Plan. Over.

198:43:15 Worden: Roger, Joe.

[Very long comm break.]

[The photography continues in black and white using magazine QQ and the 500-mm telephoto lens of an unusual, small crater west of the much larger limb crater la Perouse. Two shots are taken, AS15-81-10906 and 10907. This tiny crater is like so many of the other small, flat-bottomed, bowl-shaped craters on the Moon, except for a remarkable slump on one side.]

Public Affairs Officer - "This is Apollo Control at 198 hours, 52 minutes. ... We'll continue to stand by live in this pass. The crew [are] busy with orbital science. We're showing cabin temperature in Endeavour 75 degrees Fahrenheit [23.9°C], cabin pressure of 4.8 pounds per square inch [33.1 kPa]."
[Orbital photography returns to the colour camera with 15 frames across northeastern Mare Tranquillitatis of visual target 4, the 12.4-km crater Cauchy and its rilles and scarps. These were also imaged on the previous orbit.]

[The first is AS15-97-13194 which looks NW across the mare towards the target. Cauchy is in the foreground and Rima Cauchy can be seen north of the crater meandering under an almost overhead Sun. AS15-97-13195 is similar but aimed slightly further south to take in Rupes Cauchy, a scarp which becomes a rille at its far end. Cauchy is at the top edge of the frame. It is the major subject of AS15-97-13198 which shows its flat floor and smooth walls. Some slight banding is visible around the top of the crater walls which reflects the layered structure of the mare basalt. The northwestern end of the rille is shown in AS15-97-13199.]

[AS15-97-13200 to 13208 track along Rupes Cauchy. Four of these frames have been composited to show the length covered by these shots. Two small sections of rille are at the left end of the composite.]

[As Endeavour approaches the boundary between Mare Tranquillitatis and Mare Serenitatis, three photographs are taken of Jansen and its environs. Jansen is a flooded crater, 23 kilometres in diameter named after Zacharias Janszoon, 1580-1638, who was a Dutch pioneer of the telescope. The crater is well shown in AS15-97-13210. The slopes show up light coloured in the high sunlight, as do the slopes of Jansen Y, the bright crater inside Jansen. 13211 and 13212 look to the north at Rima Jansen, a sinuous rille. Jansen L is cut off at the corner of 13212.]

[Flight Plan page 3-311.]

Public Affairs Officer - "This is Apollo Control at 199 hours. The Flight Dynamics staff have computed the final update on the LM impact point. The coordinates are 26.362 degrees north latitude, and .253 degrees east longitude. The final aim point was 26.2 degrees north and 1.1 degrees east. The impact point represents about a 13 [nautical] mile [24.1 km] down track miss from the aim point. Impact time, final update on that was 181 hours, 29 minutes, 36.24 seconds."
[Right on the boundary between the two great mare are craters Dawes and Plinius. Whoever is concentrating on the photography in the spacecraft returns to using the camera with black and white film and the 500-mm lens.]

[AS15-81-10908 and AS15-81-10909 are a spectacular pair looking into the 18-km Dawes lit by a high Sun. Compare this with an earlier frame from the Panoramic Camera, AS15-9562P.]

[The next six images are all of details within Plinius, a classic centre-peak crater, 43 kilometres in diameter. This crater was named after Pliny the Elder, 23-79 AD, whose full name was Gaius Plinius Secundus. Pliny is credited with writing an encyclopedia on natural history which held sway until the middle ages. With the 500-mm lens, the extent of Plinius cannot be captured in one shot. AS15-81-10910 and AS15-81-10913 show the north and south rims respectively. AS15-81-10914 looks down upon the central peak, though this is only distinguishable by the lighter albedo of the slopes.]

199:08:46 Allen: Endeavour, this is Houston. We copy the Gamma-ray Gainstep, Shield, On. And Al, we have photo PAD to you when you're ready to copy. Over.

199:09:00 Worden: Okay, Joe. Go ahead.

199:09:03 Allen: Okay. In your Flight Plan, at 199:20, you can strike PCM Cable, unless your relativistic speed has managed to lengthen that cable, I guess. At 199:25, you can strike the 3 lines "CMC Mode, Verb 22, and CMC Mode." And, then I have a PAD for you at 200 plus 20, when you're ready.

[On the second day of the flight, the crew had discovered that a PCM cable was missing with only short ones available. The purpose of the cable was to encode the firing of the camera shutter into the spacecraft telemetry.]
199:09:50 Worden: Roger. Go ahead with the PAD at 200:20.

199:09:54 Allen: Okay, Al. At this time, it's camera configuration for terminator photos that we missed a little earlier. And the lines should read "CM4/EL/250/VHBW, IVL, f/5.6 at 1/125th, infinity, six frames, Mag Romeo." Over.

199:10:48 Worden: Roger, Joe. Understand. Terminator photo PAD at 200 plus 20 is CM4/EL/250/VHBW, and that's with the intervalometer, IVL, at f/5.6, 1/125th, infinity, six frames and Mag R.

[The photography will be through the right hand rendezvous window using the electric Hasselblad camera fitted with a 250-mm lens. The very high speed black and white film is contained in magazine R. The intent is to photograph the terminator with very low-angle lighting to pick out very subtle details in the shape, or topography, of the landscape.]

[As Joe Allen and Al continue with future plans, the photography is continuing with 4 images taken of Bela, the arcuate feature which is the source of Rima Hadley. Two of these, AS15-81-10918 and 10919 have been composited and show it well though the Sun is high and the features are becoming less distinct.]

199:11:13 Allen: Readback's correct, Al. And, the next entry is at - 200 plus 25, which is open the Map Camera covers and extend the camera per page S/1-39. And, at that time, Map Camera, Image Motion to On. And then, coming up to the time 200 plus 27 plus 56, EL On; and 200 plus 29 plus 36. EL Off. At the time 200 plus 30 plus 36, Map Camera, On; Image Motion, Increase; talkback to barber pole, plus 4 steps; Laser Altimeter to On; Pan Camera Mode to Standby, Power, On; Stereo, Exposure, normal. Over.

199:13:06 Worden: Roger, Joe. At 200 plus 25 open Mapping Camera covers and extend the Mapping Camera. Turn the Image Motion, On, at 275 - 200:27:56, EL On, and at 29:36, EL Off. At 30:36 Mapping Camera, On; Image Motion to barber pole, plus four; and Laser, On. And then Pan Camera, Standby, Power, On; Stereo, Exposure, normal.

199:13:41 Allen: That's correct, Al. And continuing on through a few more steps here, and I'll read them all, and then stand by for your readback. 200 plus 33 plus 29, Pan Camera, Mode to Operate. 200 plus 49 plus 32, Pan Camera to Mono. 200 plus 54 plus 27, Pan Camera, Stereo. 200 plus 59 plus 22, Pan Camera, Mode, Standby; Pan Camera, Power to Off on MSFN cue. And, moving right along, 201 plus 17 plus 00, Pan Camera, Image Motion, Increase. I'm sorry, Al. That was misread. That should be Map Camera, Image Motion to Increase; talkback barber pole. 201 plus 28 plus 21, EL On. 201 plus 30 plus 01, EL Off. 201 plus 30 plus 21, Map Camera, off; Laser Altimeter, Off. And the final one, 201 plus 32 plus 00, retract camera and close covers per the page in your checklist. Over.

199:16:27 Worden: Roger, Joe. Understand at 201:17:00, Mapping Camera, Image Motion, Increase to barber pole; at 201:28:21, EL On; at 201:30:01, EL Off; 201:32:00, Off. No, back to 30:01, after EL Off, read Map Camera, Off; Laser, Off. And, at 201:32:00, Retract and close the Mapping Camera covers.

199:17:08 Allen: Okay, Al. And read back to me 4 more lines, beginning with 200 plus 33 plus 29. You didn't go back quite far enough, and that - that one should read Pan Camera, Mode to Operate.

199:17:24 Worden: Oh, okay.

199:17:25 Allen: And I'm standing by.

199:17:26 Worden: Roger. At - at 33 - at 200:33:29, Pan Camera to Operate. At 49:32, Pan Camera to Mono. At 54:27, Pan to Stereo. And, at 59:22 Pan to Standby; Power, Off, on MSFN cue.

199:18:00 Allen: Okay, Al. Sounds real good. But double check for me one line, which I may have goofed. It's the 201 plus 30 plus 21, Map Camera, Off; Laser Altimeter, Off.

199:18:20 Worden: Roger, Joe. Understand. At 201:30:21, that's 20 seconds after EL Off, we get the Mapping Camera, Off and the Laser, Off.

199:18:33 Allen: Yes sir, that's affirmative. And, I guess - we're still waiting for an ISA weight. Other than that, we're doing real fine.

199:18:47 Worden: Okay, Joe. [Long pause.]

199:19:10 Worden: Houston, 15.

199:19:11 Allen: Go. Go ahead, Al. And, we're waiting for a Image Motion talkback to barber pole.

199:19:28 Worden: Okay. Dave's going to get the ISA weight out for you and call you.

199:19:33 Allen: Okay. If he's able to weigh it right there, I'd like to know how he's going to do it. I assume he's got it written down, though.

[Of course Dave cannot "weigh" the ISA in the spacecraft as he is in a weightless environment. On the Earth, or as they do on the Moon, the force acting upon an object due to the gravity field it is in can be measured by having it act on a calibrated spring. This gives the weight for the object in that particular gravity field.]

[Though they are near the Moon, they are in freefall around it and the force of gravity is exactly counterbalanced by the centrifugal force of their path. This makes them weightless. How might the mass of an object be determined in this environment? One way would be to use the object's inertia. Set the object in motion in the spacecraft at a known speed and measure the force it applies when it is brought to a halt. Similar to this would be to spin it around on the end of a string or pole at a known rotational rate and measure the force on the string. The distance from the centre of rotation to the object's centre of mass would also have to be known.]

199:19:43 Worden: He's got it written down. He just has to get it out.
[Long comm break.]
199:22:47 Irwin: Houston. This is 15.

199:22:50 Allen: Go ahead, 15.

199:22:56 Irwin: Yes, Joe. I have weight information on the ISA. The ISA total was 64 pounds, which includes bags 4 and 6, and 8 pounds return items. And the ISA, by itself, without anything loaded in it, was 8 pounds. Over.

199:23:19 Allen: Okay, Jim, copied that. Sounds like there might be a stone or two in there.

199:23:29 Irwin: Yeah. Bags 4 and 6, for sure.

199:23:38 Allen: Thank you, Jim.

[Long comm break.]

[Joe Allen is replaced at the CapCom console by Robert Parker.]

199:28:47 Parker: Apollo 15. We'd like Gamma-ray Shield, On, please.

199:28:58 Scott: Roger, Dr. Parker. Shield, On. [Long pause.]

199:29:48 Parker: And, 15. Time to start the terminator [photography] now.

199:29:54 Scott: Roger.

[Comm break.]

[Endeavour is about to cross the terminator and the current period of Mapping Camera photography will soon stop. Before it does, a sequence of photographs are taken with the Hasselblad on high speed film of the northwest corner of the Aristarchus Plateau. The sequence extends from AS15-98-13327 to 13335.]

[Of note among these is AS15-98-13329 which shows the old, heavily cratered surface of the plateau along the bottom of the shot. Bottom left is Raman, an 11-km crater at the western apex of the plateau named for the Indian physicist Chandrasekhara V. Raman, 1888-1970. Running along the upper third of the picture is the Montes Agricola mountain chain which extends for about 160 kilometres parallel to the northwestern edge of the plateau and about 40 km offshore. Note the apparent shoreline around the mountain spur on the right. This feature will be seen clearer on the next orbit when it is recognisable as a rille which temporarily runs along the base of the hill. Georgius Agricola, 1494-1555, was a German naturalist and physician.]

[Seen here in a scan presented by Kipp Teague, AS15-98-13331 reaches the terminator itself. The southwestern end of Montes Agricola is along the lower third and a part of a wrinkle ridge system, Dorsa Burnet, runs north-south to its left. The ridge is named after an English naturalist, Thomas Burnet, 1635-1715. Looking at images like this, it is easy to imagine how pre-space-age illustrators of the lunar surface came away with the notion that lunar hills were extremely jagged. The terminator has always been attractive to telescopic observers of the Moon and this is where vertical scale is exaggerated. The penultimate image in this sequence, AS15-98-13334, shows the sunlight catching the raised rims of the craters and the peaks of the wrinkle ridges.]

199:32:00 Parker: Mapping Camera, Standby, please.

199:32:13 Scott: Roger. Standby. [Long pause.]

199:32:49 Parker: Laser Altimeter, Off, please.

[Comm break.]
199:34:27 Parker: Apollo 15, Houston. If you have a chance, we'd like to talk to Dave and Jim about this LCG connector problem some time.
[Parker is referring back to problems the crew had in obtaining a good pressure integrity check yesterday at 177:56:39 prior to jettison of the LM.]
199:34:37 Scott: Okay, stand by.

199:34:41 Parker: And Auto on High Gain [Antenna], please.

199:34:46 Scott: Auto. [Long pause.]

199:35:02 Scott: Houston, 15. Go.

199:35:09 Parker: 15. Two questions we'd like to ask. First one's specific, and that is, if you noticed anything about the connector between the LCG and the suit when you took it out in order to put the plugs in yesterday afternoon. Was it already out? Was it loose? Was it not lock - locked? Or what? And secondly, a general question building up from this. Can you tell us anything - any insights you acquired in taking the suits off and looking at the connector or just, in general, about what this problem may have been caused by?

199:35:51 Scott: Well, I guess - I guess our first indication was lack of a good integrity check. As a matter of fact, we couldn't get much more than about a pound in the suit. And the first - In thinking it over, we - we thought the only thing it could be would be those connectors, because that was the on - only semi-open port, even though it shouldn't - shouldn't be leaking. And, everybody checked their helmet and gloves and they appeared to be locked, so we broke open the helmet and gloves and Jim reached in through my zipper and pulled out the LCG connector and stuck in the plug. And then we rezipped, or I did. Jim rezipped me. And we tried another integrity check, and it worked okay. I guess beyond that - I don't have any explanation for it, other than the only possibility is that the LCG connector was leaking, or that somebody's glove or helmet was leaking, because the suits have been, as you know, very tight all the way through.

199:36:55 Parker: Roger. Did Jim notice when you - when Jim took out your connector there, to put the plug in, did he notice it as being loose, unattached, or not lock-locked? Did he have any - could he tell any of that just reaching in with his fingers?

199:37:15 Irwin: Bob, this is Jim. The lock-lock was engaged on that water connector on Dave's suit.

199:37:22 Parker: Okay, copy. And do we understand that Dave's suit was the only one that did not pass the integrity check that first time around?

199:37:32 Irwin: No. You can't isolate it. The whole suit circuit is the integrity check. It's spacecraft plus three suits. So, there's no way to tell.

199:37:40 Parker: Roger. But on - what I mean is that you did not put - did you put plugs in Jim's suit, too, or just in Dave's suit?

199:37:50 Irwin: No, only - only in one suit. But we did go through the operation of taking off helmets and gloves, which also may have been the problem.

199:37:57 Parker: Roger. Copy that.

199:38:02 Irwin: In - in other words, there may have - even though we checked the lock-locks on the helmets and gloves, why, somebody could have had a cocked one and - and missed it. These - es - especially the - the surface equipment was - had an - an awful lot of lunar dust on it, and it was sort of hard to work. We're - we're going to get them cleaned up before the EVA, but after three runs down there, why, the connectors were getting pretty tough to work, even though we did lubricate them.

199:38:31 Parker: Roger. Copy. I don't think we have anything else, Dave. We noticed you did seem to have some trouble getting a suit integrity check the second time around, also. Is that right?

199:38:48 Scott: Yes. There was a glove that wasn't locked.

199:38:51 Parker: Okay, guess that was on the loop. Thanks.

199:39:09 Scott: I think the suit circuit's tight. I think that just might have just been one of those things, because the last one we ran was real good. It - the flow dropped down to like 6 or 7 tenths, I guess, and it would have stayed there all day long. I think we've got a good suit loop, but - I'm not worried about that at all. Just a matter of getting all the connectors cleaned up so they all work well. And ensuring that everybody gets a good lock-lock.

199:39:35 Parker: Roger, Dave. We agree too. I - it seems to us that that sounds like it was just one of those situations we run a suit integrity check for.

199:39:45 Scott: Roger. That's exactly right.

[Very long comm break.]
Public Affairs Officer - "This is Apollo Control. The suit integrity check, being discussed with Dave Scott, was the one that was performed last night prior to jettisoning of the Lunar Module. This check is a routine check of the suit loop, generally performed by pumping the suit up to about 9 pounds per square inch of pressure or perhaps a little bit more and then monitoring the decay rate and also the oxygen flow rates to the suits. On, I believe it was about 2 occasions, Scott reported, and we were able to monitor on the ground, a high flow rate, indicating that a good pressure integrity was not being maintained. After making some adjustments to the suits and particularly after inserting some auxiliary plugs in the fittings which normally, while the suits are being worn in the Lunar Module or on the lunar surface, would have water hose connections to the back packs, but which are connected to nothing when used in the Command Module. The plugs were inserted inside the suits and subsequent pressure integrity check showed the suits to be good. Throughout the day, we've been working on the problem here on the ground to attempt to understand what had happened and the conversation with Scott was to attempt to gain some additional information. As you heard, both the ground analysis and Dave Scott's analysis is that we do have, at the present, time a good suit circuit - good suit integrity checks, and that the suits and suit circuits are maintaining pressure as they should. And the implications from the conversations is, a most likely suspect, some dirt in some of the fittings. In Mission Control at the present time, we are completing a shift handover, Flight Director Glynn Lunney and his team of Flight Controllers will be replacing Gerry Griffin and his team. The spacecraft communicator on this shift is Astronaut Bob Parker."

199:49:49 Parker: And, 15; Houston. You are Go for LOS.

199:49:57 Scott: Thank you very much, Houston.

[Very long comm break.]
Public Affairs Officer - "We have about 30 seconds now until loss of radio contact with Endeavour. Spacecraft completing its 62nd revolution of the Moon and we'll be reacquiring in a little over 45 minutes. ... At 199 hours, 51 minutes; this is Apollo Control."

[Flight Plan page 3-312.]

[The 63rd orbit of Apollo 15 commences at about 200:12 GET. This far-side pass is a quiet one for the crew. The spacecraft is flying pointy-end first in what is called the "+X Forward SIM Attitude" which has the SIM bay facing the Moon. All the major instruments are operating, Gamma-ray, X-ray, Alpha Particle and Mass Spectrometers. Note that in this attitude, the inlet to the Mass Spectrometer is not facing the direction of travel so native atoms from the lunar atmosphere are not being selectively sampled.]

[Once again, as they reach the terminator, the Mapping Camera will be brought into use to photograph the daylit side. In preparation for this, both of the experiment booms are retracted and while the Gamma-ray instrument is kept powered, the Mass Spectrometer is switched off. The Panoramic Camera is also brought into play three minutes before AOS for nearly half an hour, taking 224 frames in all, most of them in stereo. Handheld photography during the coming revolution will be even more intensive than the last.]

Public Affairs Officer - "This is Apollo Control at 200 hours, 35 minutes. And we're about 1 minute away from regaining radio contact with [the] Apollo 15 spacecraft, now in it's 63rd revolution of the Moon. While the spacecraft has been behind the Moon, Flight Director Glynn Lunney has completed a status review with the flight controllers. Everything appears to be progressing smoothly at this point. And the Flight Activity Officer [FAO] reports that we should be pretty much back on the normal Flight Plan by the scheduled time for the crew to begin their rest period tonight, which would be at 203 hours, 40 minutes, or a little over 3 hours from now. And leading up to that time, we'll primarily be completing a configuration of experiments in the SIM bay, getting the spacecraft squared away and ready for the sleep period. We should have acquisition - we do have Acquisition Of Signal now. We'll stand by for a call to the crew."
[As seen from Earth, the Moon is approaching full. Most of their far-side passes are in darkness while most of their near-side passes are in sunlight. According to the Apollo 15 Index of 70-mm Photographs, the crew use four different camera magazines during the coming near-side pass, taking 124 photographs on black and white, very high speed black and white, colour and ultraviolet sensitive film.]

[The photography begins with images of a small crater right on the rim of the 77-km crater Gibbs at the Moon's eastern limb. AS15-90-12267 and 12268 are taken with the relatively wide-angle 60-mm lens while AS15-81-10920 uses the 500-mm to show it's detail. The eastern rim of Gibbs runs from top-left to bottom-centre. Unlike most small, fresh craters, this one displays dark ejecta excavated from the larger crater's rim.]

[An unusual crater with a one-sided slump, first discussed after 198:43:15, is revisited in AS15-81-10922, while 10923 spots another small crater within the floor of the larger 78-km la Perouse.]

[When the 500-mm lens is trained towards the horizon, the result is, in the opinion of this author (Woods) a quite breathtaking portrayal of the Moon's forbidding, desolate beauty as depicted in AS15-81-10924. The picture looks NNW past Maclaurin, the east rim of which is visible in the foreground. Colin Maclaurin was a professor of mathematics in Aberdeen and Edinburgh in Scotland, and lived 1698-1746. The dark, simple crater just below and right of centre is unnamed. Along the bottom-centre is the eastern rim of Mare Spumans (The Foaming Sea) and right of centre, we can see across a light-coloured crater which is Pomortsev, formerly Dubiago P, which has been named after Mikhail Pomortsev, 1851-1916, a pioneer of rocket propulsion from Russia.]

200:46:14 Parker: Endeavour, this is Houston. Over.

200:46:21 Worden: Hello, Houston; this is Endeavour.

200:46:24 Parker: Roger. We got the usual Flight Plan updates, if you'll get a Flight Plan out and copy them in, please.

200:46:37 Worden: Okay; stand by one.

200:46:39 Parker: Okay; and if someone could give us High Gain Antenna to Auto, we'd appreciate it.

200:46:59 Worden: Go ahead with the update.

200:47:00 Parker: Okay. First one is the UV photo plan - PAD at 201:05 in the Flight Plan. The T-start will be 201:11:19. Over.

200:47:17 Worden: Understand. UV T-start 201:11:19.

200:47:22 Parker: Roger. Next, at 201:20, we will delete "PCM cable."

200:47:35 Worden: Okay; got that.

200:47:37 Parker: Roger. At 202:30, it's Discriminator, Low, in that line on the Mass Spec.

200:47:52 Worden: Okay. Discriminator, Low, at 202:30.

200:47:56 Parker: Roger. At 203:21, we will delete "Laser Altimeter, Off."

200:48:11 Worden: Understand. Delete "Laser Altimeter, Off" at 203:21, and let's hold up on the rest for now.

200:48:47 Parker: And 15, 30 seconds to Pan Camera, Mono.

200:49:05 Scott: Hey, go with the rest of the updates, Bob.

200:49:08 Parker: Okay. At 203:23, we'll delete the "Mapping Camera Track, Retract, talkback barber pole, 4 minutes, gray then Off, center;" that whole line.

200:49:37 Scott: Okay; that's deleted. Next.

200:49:44 Parker: And we want Pan Camera, Mono, please.

200:49:55 Scott: It's there.

200:49:57 Parker: Roger; sorry.

[According to the Flight Plan, the time when the Panoramic Camera is switched to Mono is also when they should be taking Hasselblad photos of a point on Mare Fecunditatis where the Soviet probe, Luna 16, landed in September 1970. This spacecraft is notable for having been the first successful sample return mission mounted by the Soviets bringing back 0.1 kg of dust in a 35-cm core. A high quality suite of photographs, both by the Mapping Camera and the onboard cameras, will help in determining the context of the returned samples. The crew do eventually photograph this site extensively during rev 69.]

[Just now, they are taking ultraviolet photographs of the landscape north of one of the most prominent craters on the eastern side of the Moon's disc, Langrenus, a classic 132-km feature with heavily terraced walls and a dominant central peak. Michel Florent van Langren, c. 1600-1675, was a Belgian who produced one of the earliest maps of the Moon with named features, yet the only name which has survived from that map is for the great crater which he named after himself. This UV photography may be a replacement for the photography missed at 196:56:19, though that was intended to look at a mare area whereas these photographs are of the Langrenus ejecta blanket.]

[In this sequence, ranging from AS15-99-13457 to 13466, ten shots are taken, two each through UV filters 4, 1, 2 and 3 with a final pair taken through filter 4. Though these are intended to be analysed from the point of view of their filter characteristics, the two most interesting from a visual standpoint are from filter 4. AS15-99-13458 shows the north rim of Langrenus with the 13-km Acosta just beyond. Acosta, formerly Langrenus C gets its name from Cristobal Acosta, 1515-1580, a physician from Portugal. Along the top left, the rim of Atwood is just visible. The 29-km Atwood, named for a British mathematician and physicist, 1745-1807, is one of a triplet of craters, better seen in AS15-99-13465 which have recently been renamed from their previous alphabetic designations with respect to Langrenus. Atwood was formerly Langrenus K while in the centre of 13465 is Naonobu, formerly Langrenus B, a 35-km crater which, like Atwood, is heavily degraded and which was named after Ajima Naonobu, 1732-1798, a mathematician from Japan. The largest of this trio is the 43-km Bilharz which is partially cut off on the left of 13465. It was named after a German physician, 1825-1862.]

[Three images are presented here from the current Panoramic Camera sequence taken as the spacecraft coasts over Sinus Successus and Mare Fecunditatis (with thanks to journal contributor Robin Wheeler who scanned and donated them). Frame AS15-0112P consists of a sweep that runs from Sinus Successus to the centre of Mare Fecunditatis in the region of Lindbergh (1902-1974), a 13-km crater named after Charles A. Lindbergh, an American pilot who achieved fame by being the first person to fly solo across the Atlantic Ocean. The small crater at the top of the image is Webb U. The Soviet probe Luna 16 may reside somewhere in this image.]

[In frame 0117P, the crater at the centre is Taruntius P and Taruntius N peeks out of the top right of the image. The featureless expanse of Mare Fecunditatis continues to be the subject of 0123P which is centred just east of Taruntius H.]

200:49:59 Parker: Okay; 203:27, we'll delete "Mapping Camera/Laser Experiment, Covers, Closed, talkback barber pole, grey then Off, center;" et cetera. That whole line there. 203:27.

200:50:18 Scott: Okay. Next?

200:50:20 Parker: Okay; now we have here a little test. The guys down here would like to run with the Laser [Altimeter] to see if we can zap it a little bit and rejuvenate it, perhaps. The first step is back on 201:30. We will delete the "Laser Altimeter, Off" and "Mapping Cover/Laser Altimeter Cover, Close." At 201 plus 30. Over.

200:51:00 Scott: Are you making an update to the update?

200:51:03 Parker: Stand by here. Stand by a minute.

200:51:09 Scott: Okay; I didn't exactly find that one.

200:51:12 Parker: Yes, stand by. I got to check with OSO.

[Comm break.]
200:52:29 Parker: Okay, 15. We got a clarification on that. The "Laser Altimeter, Off" is at 201:30. The "Mapping Camera/Laser Altimeter Cover, Close" is called out at 201:32. And we want to delete both of those.

200:52:48 Scott: Stand by, Bob. We're taking pictures. We'll come back to you.

200:52:50 Parker: Yes, give me a call. [Long pause.]

200:53:45 Parker: And 30 seconds to Pan Camera, Stereo.

[Comm break.]

[Still using magazine QQ and the 500-mm lens, the crew take AS15-81-10927 which looks across Sinus Concordiae on the eastern shore of Mare Tranquillitatis. The foreground hills include the extremely degraded crater da Vinci. For such a great figure of science and art as Leonardo da Vinci, 1452-1519, it is perhaps surprising that such an inconspicuous crater should bear his name. With regard to lunar science, history credits him with being the first person to explain the mechanism behind the phenomenon of Earthshine. Beyond Sinus Concordiae in the distance can be seen the light-coloured walls of Proclus D.]

[Proclus itself is the subject of AS15-81-10928 and AS15-81-10929. This interesting crater was the subject of study by Al Worden during his solo mission at 128:07:19 and 143:52:09. The crater's distinctive ray excluded zone can be seen at the lower left. A high resolution version of the image, scanned for the journal by Kipp Teague, is included.]

200:55:33 Worden: Okay, Houston; 15. Go ahead with some updates, if you've got them.

200:55:43 Parker: Okay, Al. Did you copy? What we're doing is we're changing that update, deleting the Laser Altimeter, Off at 201:30. And then, we're also deleting at 201:32, the callout to "Close the Mapping Camera/Laser Altimeter Cover." Over.

200:56:10 Worden: Okay; I understand. At 201:30, you want the Laser Altimeter left On, and the Mapping Camera left out and the Covers, Open.

200:56:20 Parker: That's affirmative. Okay; now after the Mapping...

200:56:24 Worden: Is that what you want?

200:56:25 Parker: That's affirmative. And now, after the Mapping Camera is Off at 201:30, we want to cycle the Laser switch Off for 1 second, then On for 15 seconds, Off for 1 second, On for 15 seconds, et cetera, for 20 cycles. And after 20 cycles, we will leave the Laser Altimeter, On, for MSFN analysis. Over.

200:57:08 Worden: Okay; understand. You want at 201:30 - you want to cycle the Laser Altimeter, Off for 1 second and On 15 seconds, for 20 seconds [correcting himself] for 20 cycles, and then leave it turned on.

200:57:23 Parker: That's Roger. And we'll get back to you at that point.

200:57:30 Worden: Okay. [Pause.]

200:57:38 Parker: And that's all we have for right now, Al.

200:57:45 Worden: Roger.

[Comm break.]

[The Laser Altimeter has been failing and as a last ditch effort, they are hoping that by cycling its power switch, they might bring it back to life.]

200:58:56 Parker: And, Al, 30 seconds to Pan Camera, Standby, Power, Off.
[Comm break.]

[The next subject for the crew's Hasselblads is the Cauchy region of Mare Tranquillitatis which was extensively photographed on the previous two orbits using different film/lens combinations. The pair of linear features, Rima Cauchy and Rupes Cauchy, are the main interest of all this photography. AS15-81-10930 to 10933 look along these features from a distance. Cauchy crater is well shown in AS15-81-10938 with the high Sun bringing out the slopes of the walls. AS15-81-10939 to 10944 continue the coverage of the rille and scarp with 10941 showing the small crater Cauchy B next to Rupes Cauchy and 10944 showing the two depressions at the end of the scarp.]

[Perhaps with a thought to Al's earlier observations of the Taurus/Littrow area, and the suggestion of cinder cones, the large lens is swung round to look north up the eastern rim of the Serenitatis basin in AS15-81-10945. At the bottom of the image, just right of centre, is the dark valley floor where Gene Cernan and Jack Schmitt will explore seventeen months hence. The bright slope to the left of the valley floor is the North Massif. The South Massif, the other well-known landmark from that site is off the bottom of the frame.]

[Other notable frames from this period of photography include AS15-81-10950 which is of Jansen K, and AS15-81-10952 which shows the northern half of Jansen itself.]

[Flight Plan page 3-313.]

201:01:08 Parker: And, 15, we verify the Pan Camera lens is stowed. When convenient, we'd like Battery B Charge - Battery Bravo Charge terminated.

201:01:21 Worden: Understand, B terminated.

[Long comm break.]

[As Endeavour passes just south of Mare Serenitatis, the 500-mm lens looks at part of the Rimae Plinius system in AS15-81-10953. These rilles are part of the arcuate rille systems that surround most of the major maria and which are believed to be caused by the weight of the mare sinking and stretching the land around its periphery. Menelaus A is a small crater within the Montes Haemus range. Three photographs are taken of which AS15-81-10955 gives the best view. Notice the two bright streaks running down the crater wall.]

201:06:16 Parker: And, Endeavour; Houston. One more request, please.

201:06:20 Scott: Go ahead, Bob.

201:06:21 Parker: Roger. Since we don't have the PCM cable, we'd like to - for these UV photos - to have you give us a mark each time you press the shutter button, please, on the air-to-ground.

201:06:36 Scott: Okay; if you'd like. [Long pause.]

[Mission Control have misunderstood the situation regarding the PCM cable. When the problem first arose, they found that the cables they had would not reach from a camera eyepiece of the sextant where they had a camera attached, to one of the wall outlets. Mission Control have come to believe that no cables are available but the truth is that there are, they are only long enough for using with the cameras looking out of the main windows.]

[On the southwestern shore of Mare Serenitatis is Sulpicius Gallus and a system of arcuate rilles. These rilles and other small features are photographed on magazine R in frames AS15-81-10957 to 10968. The high sun angle washes out a lot of the detail in these images but representative among them are AS15-81-10961, a part of the rille system; 10965 and 10968 which show two of the fresher and brighter ray craters in the area.]

201:07:29 Worden: Houston, 15.

201:07:30 Parker: Go ahead. Go ahead, 15.

201:07:42 Worden: Okay, Bob. Would you like me to hook up the PCM cable to it?

201:07:48 Parker: Well, the word that I was given down here was that you couldn't reach with the PCM cable.

201:07:55 Worden: No, we're taking - we're taking the pictures out of window 5, and that's where the scientific instrument outlet is.

201:08:03 Parker: Stand by. [Pause.] 15, if you can do that, that's fine.

201:08:14 Worden: Okay; I'll tell you what, Bob. I'll go ahead and hook up the PCM cable, and - and you tell me if you're getting a signal down there after I start taking pictures.

201:08:23 Parker: Okay. [Pause.]

201:08:31 Worden: And the word you got on it was - was correct. It looks like window 5 is about the only window that can be used for the PCM cable.

201:08:38 Parker: Roger.

[Comm break.]
Public Affairs Officer - "The ultraviolet photography, which the crew is preparing to perform in about 2 minutes, is done with the Hasselblad electric camera, mounted on a special window bracket. The purpose of the experiment is to obtain ultraviolet photographs of the Earth and the Moon, and these will be used in a study of planetary atmospheres. They will also be used for investigation of short wavelength radiation from the lunar surface."

201:10:21 Parker: And, Endeavour, we won't be able to see that PCM real time, but we'll just assume that it's coming down if you've got the PCM cable hooked up.

201:10:30 Worden: Okay, Bob. I got it hooked up. [Long pause.]

201:11:07 Parker: 30 seconds to UV photos.

201:11:13 Scott: Okay; thank you.

[Long comm break.]

[The second period of UV photography on this orbit is centred around the crater Conon, situated just beyond the Apennine Front. This photography is intended to cover an area of terra, or lunar highland as opposed to the earlier sequence which was to photograph mare. The pattern follows this previous example at Langrenus except that only one of the first pair of images is taken, making nine in all. This is AS15-99-13467 and is probably the most visually appealing image showing the 22-km crater Conon.]

[Returning to magazine QQ, 6 photographs are taken of Beer and Feuilée, a pair of craters, 10.2 and 9.5 km in diameter respectively, situated between Archimedes and Timocharis on the eastern side of Mare Imbrium. The 6 images can be divided into two sequences that scan across the pair, one of which has been composited from AS15-81-10972 to 10974. Of particular interest in this picture is the crater chain leading up to the southern rim of Beer. Over the history of studying the Moon, it has been difficult to pin down an explanation for these chains, which are scattered across the lunar surface. They place order and straight lines into a landscape which is otherwise characterised by the disorder and randomness of impact from extralunar sources. Until 1994, crater chains were explained as volcanic vents along a fault or collapsed portions of lava tubes. Some of the more irregular chains were found to be from impacting ejecta thrown out by very large primary impacts far away. Then the discovery of comet Shoemaker-Levy 9 and its subsequent astounding impact into Jupiter in July of 1994, gave another theory, that of gravitationally disrupted bodies which are pulled by tidal forces into strings of impactors which form lines as they strike. What formed the chain next to Beer is unknown to this author (Woods).]

201:18:11 Worden: Houston, 15.

201:18:12 Parker: Go ahead, 15.

201:18:16 Worden: Okay, Bob. When we took the - the shade out of window 5, window 5 still appears very clean.

[Window 5 is different to the others in that its panes are made from quartz to allow UV radiation to pass through.]

[A single photograph, AS15-81-10975, is taken of a small, triple-peaked hill situated between the major Imbrium craters Timocharis and Lambert.]

201:18:21 Parker: Copy. [Long pause.]

201:19:16 Parker: And, Endeavour, two questions if you've got a chance, between now and terminator photo.

201:19:24 Worden: Say again on the terminator photos, Bob.

201:19:28 Parker: Roger. Do you have time for a couple of questions, between now and the start of the terminator photos.

201:19:34 Worden: Yes, sure. Go ahead.

201:19:36 Parker: Roger. First, any comments on the Mass Spec. boom retraction, you did a half hour ago.

201:19:45 Worden: No, no comments on it. And - I guess we're back to the position we were in before, that the thing is sort of half barber pole. And when I go back out with it - fiddle with it a little bit, the barber pole goes full up and then comes down about halfway again.

201:20:16 Parker: Okay; we copy.

201:20:18 Worden: And that's where it stands right now.

201:20:20 Parker: Okay. Second question...

201:20:22 Worden: I played with it for a while, and then got busy in other things. But I'll continue - I'll continue working on it.

201:20:30 Parker: Copy, Al. Second question, do you want me to continue giving the - you these real time marks on air - air-to-ground, just before and after various camera passes?

201:20:49 Worden: Yes, I like the reminder, Bob.

201:20:52 Parker: Okay; 30 seconds...

201:20:53 Worden: Don't expect an answer, I'll probably be busy doing it.

201:20:56 Parker: Hopefully. 30 seconds a good time?

201:21:00 Worden: Roger. [Long pause.]

201:21:42 Worden: And, Houston; 15.

201:21:44 Parker: Go ahead. [Pause.] 15, go ahead.

201:21:54 Worden: Okay; for your info, the Mass Spec. took about - oh, maybe 7 or 8 cycles this time, before it came all the way in. And the same operation as before.

201:22:07 Parker: Roger; copy. It took you 7 or 8 cycles to get it all the way in.

[Long comm break.]
Public Affairs Officer - "Al Worden's last comments referred to the Mass Spectrometer boom. He reported that it required about seven or eight cycles to get the - of the switch to get the boom to retract fully from it's extended position. That boom extends out about 24 feet [7.3 metres] from the Service Module. And we have previously noticed some problems in retracting the boom. It appears that these problems, usually a slow or balky retract, occur when the retraction is attempted in darkness leading to the suspicion that perhaps a cable is stiffening up and causing the thing to be balky to retract. We don't appear to have the problem when it is retracted in full sunlight. This last retraction attempt was done at sunrise, which would go along with the theory at that point would still be cold, would not have had a chance to warm up from direct exposure to the Sun. The instrument itself is continuing to function very well - the mass spectrometer - and we're getting very good data from it; the problem being in the boom mechanism that extends and retracts it. And, insofar as possible, we will attempt to do the retraction while the boom is in sunlight."
[Shadows are lengthening as Endeavour coasts across Mare Imbrium while the crew take 11 photographs of features on its western side. AS15-81-10976 looks slightly west of north towards Sinus Iridum (Bay of Rainbows). To give context to this frame, I have marked out its approximate field of view on IV-134M, an image from the Lunar Orbiter IV probe which photographed much of the Moon in 1967. On 10976, the large, dark crater left of centre is Helicon (25 km, 1.9 km), with Helicon B (5.6 km wide, 1.1 km deep) being the bright crater in the foreground. In the distance is Promontorium Laplace, the northeastern cusp of Sinus Iridum, a strikingly beautiful bay on Mare Imbrium's northwestern shore. The full scale of this semicircular formation, formed out of a 260-km crater, can be appreciated in the Lunar Orbiter IV photograph. Its formation went something like this. 3.84 aeons (billion years) ago, a large object struck the Moon to form the Imbrium basin, a huge depression, 1,250 kilometres across, with multiple rings. The Apennine range where Dave and Jim landed is part of the rim of this great basin. Sometime during the next half billion years another object crashed down on this rim, opposite the Apennines, where we now see Sinus Iridum. About 3.3 aeons ago, vast quantities of lava began welling up through fissures in the heavily faulted crust, filling the Imbrium basin to form the mare surface we see today, breaching one side of the Iridum crater and inundating it. Lava probably issued from within the Iridum wall also, leaving Sinus Iridum as a giant bay facing out to the expanse of Mare Imbrium. Now when we look at the surface of the mare and its bay, we see the scattered result of impact over the last 3 or so aeons, minor when compared to the cataclysmic pounding suffered by the Moon in the aeon before.]

[Chuck Wood, Lunar expert and editor of Lunar Photo of the Day - "We see the Moon from such as vast distance that our views mostly have overhead perspectives (except along the limb). Often I have wondered what a particular feature look like on the ground. The Apollo images from the lunar surface provide that view for six spots, but some of the astronauts' low oblique images give a near ground perspective for more areas. And these images are often little known. This is the case for this low perspective looking across northern Mare Imbrium to the edge of the Sinus Iridum crater, which is called Promontory Laplace. This 2.6-km high headland is a fascinating lunar landform that I have observed many times, but until I stumbled across [AS15-81-10976] had no idea what it looked like in profile. This view is essentially a cross-section through an impact crater rim. The right side slopes gently (about 8 degrees) down to the surrounding terrain, whereas the inner crater rim (left side) is much steeper - about 25 degrees. The outer rim slope is due to the feathering out of the rim uplift and ejecta, and the steep inner slope results from terrace-forming collapses.]

[Further on, the crew take AS15-81-10978 of a hill 40 km WNW of Mons La Hire, 10980 of a crater cluster 50 km further northwest again, and 10983 of an unusual key-shaped crater about 70 km southwest of Delisle. While flying past Delisle, 10981 and 10982 take in the Y-shaped Rima Delisle which runs away from the northeast side of the 25-km crater. On the opposite side of Delisle is a narrow hill, Mons Delisle, which is covered in photos 10984 to 10986. The context of these two features with their associated crater is seen in AS15-88-11977, taken with the wide-angle lens on colour magazine TT.]

[The photographs taken subsequently on magazine TT are a spectacular collection of the Aristarchus Plateau. AS15-88-11978 looks south across the Harbinger mountains to the flooded crater Prinz. The rilles to the left of Prinz were discussed two orbits ago. The north half of the plateau and the terminator beyond are beautifully shown in 11979 with the northern meanderings of Vallis Schröteri peeking out past the edge of the Command Module window. The 7-km crater in the foreground is Toscanelli, named after a 15th century Italian physician and map-maker. The tendency for sinuous rilles to appear from craters in this region is also visible here. The mountain chain, Montes Agricola, runs in an arc up to the line of the terminator. It was also photographed one orbit ago. Named after a Danish astronomer, the 10-km Nielsen is north of this range.]

[Taken from Kipp Teague's Apollo Image Gallery, AS15-88-11980 is a wonderful, breath-taking image looking southwest towards the relatively young Aristarchus, the older, flooded Herodotus and the complex system of rilles and ridges surrounding them. Though the impact that formed Aristarchus occurred when life was only beginning to be established on the landmasses of the Earth, the blasting of ejecta across the mare surface is very apparent in this photograph, almost as if the event occurred in recent times. Below Aristarchus, a rille has been partially filled in by the blanket of material sweeping out from the impact. Look to the lower left and you can see the roughly V-shaped clusters of secondary craters which point to their origin as impacts from strings of rock debris thrown out with that blanket. Most of the other major features far predate Aristarchus, having origins that are linked to the outpouring of the mare lavas over 3 aeons ago.]

[Despite the profound antiquity of the features seen in this photograph, this region has been of intense interest to those who study the Moon, be they called astronomers, selenographers or lunar geologists, because of persistent tales of red spots and gaseous clouds seen through Earthbound telescopes by even well-respected observers. Leading from Heredotus on the right is the so-called Cobra's Head, the start of Vallis Schröteri. These features and Aristarchus itself have all been the site of these TLPs (Transient Lunar Phenomena).]

[Montes Agricola and the edge of the Aristarchus Plateau are beautifully captured in AS15-88-11982, while 11984 shows the immense topographical detail of the wrinkle ridges on Oceanus Procellarum on either side of the mountain chain. In 11983, the northern tip of Montes Agricola points to Nielsen. An unnamed wrinkle ridge weaves across Oceanus Procellarum towards Mons Rumker right on the terminator. The two light marks between Nielsen and Mons Rumker are reflections of cabin lights in the CM window.]

[Also marked in the Apollo 15 Index of 70-mm Photographs as having been taken during this revolution are another 7 photographs taken on magazine PP using a wide-angle lens. AS15-90-12269 looks southwest towards the Aristarchus Plateau with the western edge of Prinz visible on the left. A double crater dominates the centre with Krieger being the larger, 22-km flooded ring with the more recent 10-km Van Biesbroeck obscuring its southern rim. Johann Krieger, 1865-1902, a German, combined the new craft of photography and the ancient art of drawing when making lunar illustrations. George Van Biesbroeck, 1880-1974, was an American astronomer born in Belgium. To the right of the photograph is Wollaston. This simple crater, 10.2 km in diameter, gets its name from an English scientist, William Hyde Wollaston, 1766-1828. This group of craters is photographed again as Endeavour made its closest approach in AS15-90-12272 and 12273. 12271 looks across the northern half of the Aristarchus Plateau. Vallis Schröteri can be seen on the left, Montes Agricola on the right and the large crater in the foreground is Toscanelli. The final pair of this sequence, 12274 and 12275 look down upon the northern end of the Montes Agricola chain.]

201:27:50 Parker: 30 seconds [to] the terminator photo start.
[Comm break.]

[The crew return to using magazine R for the terminator photography, taking a total of 21 frames. The point of this imaging is to use very high speed black and white film to capture subtle details of topography in the low-angle sunlight. With this illumination, raised crater rims, which are in reality gentle artifacts of crater formation, become exaggerated to give the appearance of being great walls around deep, black pits so beloved of scenery designers in early science fiction illustrators.]

[AS15-98-13345 shows three rille features west of Vallis Schröteri which are so typical of the volcanic features of this area. On the right, the area which is more deeply cratered is the edge of the Aristarchus Plateau. In four images taken right at the terminator of which 13348 is a good example, the apparently smooth mare surface seems to be heavily peppered with great pits. It should be remembered, however, that the rough relief is illusory, brought about by the extremely low Sun. The area in view is north of the crater Schiaparelli. This 24-km crater is spectacularly caught on the terminator in 13351 with its rims just catching the early morning Sun. 13354, 55 and 56 have been composited to show the view looking north along the terminator and the wrinkle ridges, punctuated by simple, more recent craters. The crater at the extreme left is Naumann, named after a German geologist Karl Friedrich Naumann, 1797-1873.]

[The area shown in AS15-98-13357, 13358 and 13359 is an otherwise unremarkable expanse of Oceanus Procellarum transformed by the lighting angle into a riot of detail. Virtually invisible at all other times is the ghost crater seen in a composite of 13360 and 61. Nearby wrinkle ridges seem to be transformed into mountain ranges near the tiny fresh crater, Seleucus E northeast of Seleucus. The ghost crater around Seleucus E is a tell-tale of a crater that lies submerged beneath the basalt that once flowed as lava over its rim. Seleucus itself is a 43-km crater that sits isolated at the eastern edge of Oceanus Procellarum. Although beyond the theoretical terminator, its eastern rim rises high enough to catch the Sun. It is captured in AS15-98-13362 and 13363. The crater is named after a Babylonian astronomer who lived circa 150 B.C.E. Though he predates Copernicus by over 1,600 years, he was a supporter of the heliocentric, or sun-centred theory of the solar system.]

201:30:03 Parker: Terminator photo stop.

201:30:13 Worden: Roger, Bob.

201:30:21 Parker: Mapping Camera, Off.

[Comm break.]
Public Affairs Officer - "This is Apollo Control. The crew has now completed the photography of the terminator using the electric Hasselblad camera and also the Mapping Camera in the Scientific Instrument Module bay. We're standing by now for them to begin a procedure which we hope will possibly solve the problem with the Laser Altimeter. About 35 or 40 minutes ago, we asked the crew to..."

201:32:47 Parker: And, Endeavour; Houston. Be advised, we like an accurate 15 seconds, On; 1 second, Off. No more than 16 or 17 seconds, On.

201:32:59 Worden: Roger; understand.

[Long comm break.]
Public Affairs Officer - "What Al Worden is doing is cycling the switch on the Laser on and then off. And it'll do this 20 times. The hope is that in cycling the switch it will cause a particular circuit in the laser altimeter to fail. This circuit is used to discharge high voltage from some of the components and in discharging the voltage, it's thought that perhaps we're introducing some noise into the altimeter which is in turn causing the intermittent flow of data from that particular instrument."
[The spacecraft is rotated 180° from a pointy-end-forward attitude to one with the SPS engine facing the direction of travel. The SIM bay continues to face the surface before and after the maneuver.]
Public Affairs Officer - "Al Worden has completed cycling the switch on the Laser Altimeter; and the Orbital Science Officer reports, from the telemetry, it appears that the procedure did no good, that the Laser Altimeter is still not functioning properly."

201:38:43 Parker: And, 15. Roger; thank you. Unfortunately, like everything else, the Laser didn't do much good. We'd like now, Mapping Camera to Standby; Laser Altimeter, Off. Then we'll do the Retract and Door Close. Over.

201:39:03 Worden: Okay, Bob. We'll go Mapping Camera, Off and Laser, Off.

201:39:07 Parker: We need Mapping Camera, Standby, please.

201:39:15 Worden: Roger; Standby, and Image Motion, Off, and Laser Altimeter, Off. And retracting the - retracting the camera now.

201:39:30 Parker: Copy.

[Long comm break.]
201:46:10 Scott (onboard): Boy, that's ...

201:46:13 Worden (onboard): We didn't put it in my safe place.

201:46:18 Scott (onboard): Are you at P51?

201:46:20 Worden (onboard): I'm not there yet. See, I cleaned that thing religiously, all - every night?

201:46:28 Irwin (onboard): No...

201:46:29 Scott (onboard): But we didn't...

201:46:30 Irwin (onboard): ...

201:46:31 Worden (onboard): But - but we didn't get it last night, I don't think.

201:46:32 Scott (onboard): No, it's all that crap we brought in here.

201:46:34 Irwin (onboard): Yes. Yes. Yes. Feel the difference already in air that's blowing out of the hose. It really does make a difference. Yes.

201:46:47 Scott (onboard): I thought it was practically suffocating.

201:46:51 Worden (onboard): Probably that, and the combination of going in dark.

201:46:58 Scott (onboard): Oh, gosh. They're sitting there in their own comfortable console.

201:47:02 Irwin (onboard): ...

201:47:03 Scott (onboard): ...

201:47:04 Worden (onboard): Yes, that's right.

201:47:05 Parker: And, Endeavour; Houston. Over.

201:47:11 Worden: Go ahead.

201:47:12 Parker: Roger, Al. If you could get us a film budget status on the backside to give us when you come around, we'd appreciate it. And except for that, you're Go for LOS.

201:47:24 Worden: All righty. Thank you, sir. And we'll see if we can conjure one up for you.

201:47:29 Parker: Good enough.

[Very long comm break.]
Public Affairs Officer - "This is Apollo Control. We're now about 1 minute, 15 seconds from losing radio contact with Endeavour. On the next revolution, the crew will be eating and then we plan to put them to bed. And we've had Loss Of Signal now. We'll hear from the crew again in about 45 minutes. At that time, they'll be at the beginning of their 64th revolution of the Moon. At the present time, the spacecraft is in an orbit 66.8 by 51.8 nautical miles [123.7 by 95.9 km]. At 201 hours, 49 minutes; this is Apollo Control."

[Soon after LOS, Al carries out another realignment of the guidance platform in which it is realigned to the lift-off REFSMMAT. Afterwards, the experiment booms are deployed and the DAC (Data Acquisition Camera, a 16-mm movie camera) prepared in a special bracket to look out window 5, via a mirror, at the Mass Spectrometer's boom and the Moon below for an entire daylight pass (1 hour and 15 minutes). The camera will run at one frame per second starting just before they reach the terminator at about 15 minutes before AOS.]

[Flight Plan page 3-314.]

201:50:50 Worden (onboard): ...? Yes, I need to get him a status of the command module. Joe - we'll give it to him when we come around next time.

201:51:38 Scott (onboard): That's the stuff ...

201:52:35 Worden (onboard): You tell me when - You tell me when ... that flight data ...

201:54:28 Worden (onboard): What's you doing? What's you doing? Throwing away dirty stuff? ...

201:54:40 Irwin (onboard): ...

201:54:44 Worden (onboard): ...You didn't put on clean tonight, did you?

201:54:46 Irwin (onboard): ...

201:54:47 Worden (onboard): Oh. Your last one? Guess you got stuck with it, Jim. ...

201:55:26 Worden (onboard): (Laughter) I've got a little job for you to do, Jim. Assemble camera, lens, mirror, and magazine on special window-5 bracket; rotate the lens 180, so we can take pictures of the mass spec. You do that in - about 15, 20 minutes. Well, we use the - we use the 16 millimeter. And the bracket's down in A-8. You know, that big bracket down there. You do that while I'm...

201:56:09 Irwin (onboard): I don't see it.

201:56:10 Worden (onboard): ...while I'm doing a P52. Oops! Excuse me, Dave. ...

201:56:18 Scott (onboard): ...

201:56:21 Worden (onboard): Yes, I know. God dang, it's not very crowded down here!

201:56:39 Scott (onboard): Hey, you got to this ...

201:56:40 Worden (onboard): Okay. We'll - we'll get it. I'll get it. Keep going. I'll get it.

201:56:44 Scott (onboard): ...

201:56:47 Worden (onboard): I used to do it by myself. No big deal.

201:57:08 Worden (onboard): Okay, as long as you're in the couch, how about putting me in Free? Mode to Free.

201:57:14 Scott (onboard): Okay.

201:57:36 Worden (onboard): Star 1.

201:58:56 Worden (onboard): Star 40.

201:58:57 Irwin (onboard): Where?

201:58:59 Worden (onboard): Out there.

201:59:47 Scott (onboard): Wooo!

201:59:52 Worden (onboard): ...

202:00:04 Irwin (onboard): ...

202:00:06 Worden (onboard): Huh?

202:00:07 Irwin (onboard): ...

202:00:09 Worden (onboard): Let's see. ... 202:00:30.

202:00:43 Worden (onboard): Jim wants to know if his camera ... on the mass spec stuff.

202:00:59 Worden (onboard): Jim, you want to get the - the mass spec boom and gamma ray boom on their way out now? Might as well go ahead and do that.

202:01:08 Irwin (onboard): Mass Spec Boom, Deploy. ... find it?

202:01:11 Worden (onboard): No, just get it out.

202:01:13 Irwin (onboard): Do you want to...

202:01:14 Worden (onboard): We got time for it.

202:01:15 Irwin (onboard): ...

202:01:16 Worden (onboard): Yes. Okay, mass spec boom photography, 16 millimeter - Mag L. What mag's on there? E is on there now?

202:01:37 Irwin (onboard): ...

202:01:57 Worden (onboard): Here, you've got to put this UV thing in the window, too.

202:02:02 Irwin (onboard): I'll have to go back.

202:02:36 Irwin (onboard): Okay. I took all this - extra film and ...

202:02:38 Scott (onboard): ... You got plenty of places in here, right?

202:02:43 Worden (onboard): Yes.

202:02:47 Scott (onboard): ... remember ...

202:02:52 Worden (onboard): Okay.

202:02:53 Scott (onboard): You'll never get it all used up if you ...

202:02:55 Worden (onboard): That's right. We'll never have time to use it all.

202:03:04 Scott (onboard): ...

202:03:20 Worden (onboard): Yes. Is there any further use for the vacuum cleaner and all this...

202:03:25 Irwin (onboard): ...

202:03:26 Worden (onboard): ...stuff hanging around here?

202:03:28 Irwin (onboard): ... Put the bag and brush in ...

202:03:39 Worden (onboard): Okay.

202:03:47 Irwin (onboard): ...

202:03:48 Worden (onboard): Yes.

202:03:53 Scott (onboard): ...

202:04:13 Scott (onboard): You've got to use it for ...

202:05:07 Scott (onboard): What have you got in there now?

202:05:11 Worden (onboard): Where did you...

202:05:12 Scott (onboard): ...

202:05:13 Worden (onboard): ...where'd you leave the filter and all that stuff?

202:05:16 Irwin (onboard): ...

202:05:17 Worden (onboard): Okay. Might as well leave it all there, huh?

202:06:19 Worden (onboard): I think before activities get too far away, I will take a crap.

202:06:24 Scott (onboard): Is that so?

202:06:25 Worden (onboard): Yes. Jim, will you unplug me, please? You guys got the comm.

202:06:29 Irwin (onboard): ...?

202:06:30 Worden (onboard): Yes.

[The 64th orbit of Endeavour begins at about 202:10 with AOS at 202:33, almost a quarter of an hour into their meal period.]
Public Affairs Officer - "This is Apollo Control; and we'll be back in radio contact with Endeavour in about one minute. The spacecraft is now on its 64th revolution of the Moon and the orbit at the present time is 66.8 by 51.8 nautical miles [123.7 by 95.9 km]. On this pass, the principal activity will be to get everything set for the crew to begin their rest period. They have an eat period scheduled and we'll be getting the regular pre-sleep status report from them. We do have an update on the numbers for the total sample collected on the lunar surface. The gross weight of the samples - the weight of the rocks and soil plus the containers - is 226 pounds [102.5 kilogram] and our best estimate at the present time as to the net weight of the samples alone is 175 to 180 pounds [79 to 82 kilograms]. And as we have Acquisition Of Signal now on the spacecraft."
[After AOS but before the first communication from the ground, the 60-mm wide-angle lens and mag PP with black and white film are used to take AS15-90-12276 which shows the southwestern half of Sklodowska, a 130-km crater they photographed in detail two orbits ago. To the left of the image and overlying an older crater is the 53-km Schorr which lies right across the 90°East meridian.]
202:40:00 Parker: And, Endeavour; Houston. Over.

202:40:10 Scott: Houston, Endeavour, go.

202:40:11 Parker: Roger, if you - Roger, if you guys give us an Accept, we'll send you up a state vector and time uplink.

202:40:24 Scott: Roger, you've got it.

[The computer has been placed in a mode that allows it to accept data from Earth.]
202:40:25 Parker: Copy. And if you fellows will give me a call in the middle of your eating there, when you got time, we'll do some talking at you.

202:40:41 Scott: Okay, give us about five minutes here.

202:40:44 Parker: Okay.

[Comm break.]

[Their meal break has another half hour to run.]

202:43:17 Parker: And 15, its your computer. Over.
[With the uplinking of the state vector complete, the Up Telemetry switch can be returned to Block, i.e. it blocks incoming data.]
202:43:23 Scott: Roger. [Long pause.]

202:43:49 Scott: Houston, Endeavour. We're ready to chitty-chat, if you like.

202:43:53 Parker: Okay. While you guys are eating your supper there, it might be a good time to get a report on your food so far. How's it been going?

202:44:03 Scott: Oh, I think we have consumed every meal as planned and we've made a pretty good cut into the pantry.

202:44:11 Parker: You've made a pretty good cut into the pantry, you say?

202:44:17 Scott: Roger. That extra little box over there with extra little goodies.

202:44:21 Parker: Okay, and can you guys give us any estimates on the water that you and Jim consumed on the surface, say in the LM and on the EVA, and any differences between this and what Al's been consuming?

202:44:39 Scott: Not without sitting down and doing some thinking about it. We'll be glad to do that, if you like.

202:44:45 Parker: Roger. If that's not too much trouble, I guess we could start out by some estimate as to how much you guys were drinking in the LM on the EVA. Was the drink bag adequate, or what?

202:44:59 Scott: Oh, I think that is probably a good discussion for the debriefing after the flight.

[They do discuss it during the debriefing. Jim's inability to drink properly from his drink bag made his EVAs all the harder, especially during the first moonwalk.]

[Irwin:, from the 1971 Technical Debrief - "I might make one comment, Dave. You know, coming back to the LM in preparation for the ALSEP, I felt that I was thirsty and kind of hungry, and I tried to get some water out of the water bag as we were approaching the LM. Couldn't get any water out of it, but the food stick was there and I gobbled that down. I think that was the thing that pulled me through and gave me the energy to get through the ALSEP deployment. That really perked me up. I felt great after that."]

[Scott, from the 1971 Technical Debrief - "That's a good point. I, too, when we got back to the LM, tried the water and the food stick, and my water worked fine. I got several gulps of water. It was very refreshing and I ate about half of the food stick at that time. That helped quite a bit. I think in looking at it, the problems I had with the water bag were related to tie-down to the neck ring with only Velcro. On the second EVA, that came loose and I could never get to the water bag because it caught under my chin. I think, maybe, if we had snaps in there, or some firmer method of tying it down, it would have helped me. [To Jim] Can you sort out why you couldn't get to the thing?"]

[Irwin:, from the 1971 Technical Debrief - "I could get to it. I just couldn't suck the water out. I just couldn't make the valve operate."]

[Scott:, from the 1971 Technical Debrief - "I'll tell you, the water bag is really a valuable asset because one quick swish of water and it really refreshes you. I think, if you really got thirsty, you could stand there and drink the whole thing, if it worked right. There was no problem putting it in the suit, no problem donning the suit with the water bag full, or with the food stick."]

202:45:09 Parker: Okay. Sounds like you are at least eating and drinking a lot so far. We are anxious for you all to continue eating and drinking well, because of the EVA yet to come.

202:45:21 Scott: Oh, okay. Well if that's your - your interest, yes, we - we consumed quite a bit of water on the surface, and we were quite satisfied with what we had. We had plenty. And we've been eating and drinking a lot up here. I think everybody is in fine shape and ready to take care of what is on - on the Flight Plan the rest of the way.

202:45:42 Parker: Sounds good. One other specific point we'd like to clear up, Dave, which I guess was a little muddled this morning. Did you and Jim take a Seconal last night or not?

[Seconal is the trade name for a secobarbital, a barbiturate drug carried in the spacecraft. Its sedative properties allow the crew to quickly go to sleep.]
202:45:53 Scott: No, there's been no medication taken by anybody on the flight.

202:45:57 Parker: Okay. However, I - we down here would like to recommend for all three of you to take one tonight just to make sure we get another good night's sleep.

202:46:09 Scott: I think that's unnecessary.

[Last night, at 180:01:47, Deke Slayton suggested that Dave and Jim, and Al if he wanted, take medication to help them rest. Though physically tired, Dave felt elated and relaxed and that sleeping pills were unnecessary.]

[Scott, from 2000 correspondence - "In my view (which I did not express at the time), taking a sleeping pill was ridiculous! So I guess we politely declined. However, I probably suspected that maybe the docs were being conservative, which is their job - but the Seconal did not fit in any case."]

[Dave also had misgivings about whether some elements of NASA upper management really comprehended how an advanced Apollo mission worked.]

[Scott, from 2000 correspondence - "Therefore, sometimes when we received 'suggestions' from Mission Control, we quickly realized the potential source, and considered them 'throwaway' - as in this case. In my view, and relative to Mission Control, 'they' (the NASA management chain) should have just let the Flight Director run the mission with absolute authority and accountability, and left it at that. But that's not realistic, I know, humans just don't operate that way, especially upper management humans! But more of them could have taken the time to join us during our training and learn something of substance about the mission and what we had to do. This is represented by my perceived source of the Seconal recommendation."]

[However, the crew were not aware of the flight surgeons' concern at heart irregularities in the EKG traces of both Dave and especially Jim during their lunar stay. This Premature Ventricular Contraction (PVC) condition was thought to have been caused by a potassium deficiency brought on by the rigours of their training and the early days of the flight. Jim also thought dehydration was to blame as he had been unable to use his drinking bag properly out on the surface. Apollo 16 and 17 avoided the PVC problem because their onboard drinks were laced with potassium.]

[The relationship between pilots and doctors has always been difficult and more so when the pilots became astronauts. Slayton himself was very aware of this having been pulled from flight status during the Mercury project when fluctuations in his heartbeat were noticed by the doctors. A maxim most pilots know is that after a visit to the doctor, there are only two possibilities; either you are fine or you are grounded. Gerry Griffin was one of the Flight Directors during Apollo 15.]

[Griffin, from 2000 correspondence - "The astronauts AND the flight controllers always felt the doctors were too nervous about the crew's health. While I must admit that the doctors often frustrated me in this regard, the ensuing years have softened my feelings somewhat about the doctors. First, in the late 60s/early 70s, a full understanding of the effects of weightlessness on a person's short-term and long-term health was still somewhat in question. Two, the doctors dealt with less-than-cooperative 'patients', the astronauts. This relationship was/is no different than you see between aircraft pilots and their flight surgeons. Third, the doctors had very little real data to make a accurate diagnosis. And, fourth, the press loved to explore the realm of sick astronauts, etc., and this always put more attention on astronaut health than it really deserved."]

202:46:12 Parker: Well, that's our recommendation anyway. And can you tell us who plans to sensor up tonight, Dave.

202:46:19 Scott: Okay. Roger. I guess as per our agreement this morning, why - you'll get CMP and a LMP tonight.

202:46:29 Parker: Roger; understand. And then we'll press on with the normal Flight Plan tomorrow. And, Al, we'd like to have you - you wear the lightweight headset tonight, because then, we'd like to wake just Al up on schedule so he can do us a P20 to - give us some plus-X time on the Mass Spec. And so we'd like to - arrange it that way, if its convenient with you guys.

[The term "plus-X time on the Mass Spec." refers to the direction the spacecraft is pointing while the Mass Spectrometer is operating. During the last LOS, Al rotated the CSM so that the SPS engine, and therefore the minus-X axis faces the direction of travel. This rams any molecules that are constituents of the lunar atmosphere into the rear-facing inlet of the instrument. Sometime during the sleep period, Mission Control wants Al to return the spacecraft to the plus-X, or pointy-end-forward attitude as part of the science investigators' attempt to discriminate between detection of the lunar atmosphere and readings due to contamination from the spacecraft. In the plus-X attitude, readings would tend to be only from spacecraft contaminants.]
202:47:00 Scott: No, I don't think that's practical, Bob. You can't have one person awake in here and the other two sleeping. It - just can't do it.

202:47:08 Parker: Okay; understand. And to avoid what we had last night with all those last minute calls again and again and again, why don't you guys give us a final call just before you're ready to go to sleep. We'll get a final status down here, and then we won't - we won't have to keep calling back tonight.

202:47:26 Scott: Oh, that's a good idea. All right. We'll do that.

202:47:29 Parker: It got a little embarrassing down here after a while.

202:47:35 Scott: Oh aw, that's okay. Yesterday was a long day.

202:47:38 Parker: Roger that. And we got a TEI-69 PAD down here, when Jim's ready to copy. And we're also ready to copy some torquing angles from that P52, if you got them. And we'd like you to leave your High Gain Antenna at plus 25 and 185 on Yaw and in Narrow and Reacquire as you go around the corner this time.

202:48:06 Scott: Oh, okay. You want Narrow, Reacquire and plus 25 and 185. We'll do that. If you're ready to copy, I've got the P52.

202:48:14 Parker: Roger. I'll copy that now.

[Just after LOS, Al made two star sightings of Alpheratz (in Andromeda) and Altair (in Aquila) which the computer used in Program 52 to work out by how much the guidance platform's attitude needed to be adjusted to restore perfect alignment. Normally, if this P52 procedure is carried out in view of the Earth, Mission Control can read the realignment angles via telemetry as they are brought up on the DSKY. Since this realignment was carried out during LOS, they need to be read down manually.]
202:48:19 Scott: Okay. Noun 05 was .01; Noun 93 was plus .07, minus .47, minus .05. They were torqued out at 202:00:30.

202:48:36 Parker: Roger. Copy .01, plus .07, minus .47, minus .05, and 202:00:30.

202:48:49 Scott: Roger. That's cricket. [Pause.]

[To translate, the error in Al's star sightings, Noun 05 was only 0.01°. Noun 93 gives the three angles by which the platform was rotated for perfect alignment. Dave has made a very understandable mistake in reading these angles. The DSKY does not display a decimal point and the crewman is expected to know that a reading of 00001 for Noun 05 means an angular error of 0.01° (one hundredth of a degree), and that 00007 in the first register of Noun 93 means a change in the platform's X-axis angle of 0.007° (seven thousandths of a degree). He realises his error soon enough. The three angles by which the X, Y and Z axes must be torqued to restore alignment are 0.007°, 0.047° and 0.005° respectively.]
202:49:00 Parker: And, Dave, we'd like Optic, Zero, at this time, please.

202:49:05 Scott: Oh, yes, Optic, Zero. Hey, by the way, I - I should have said .007. Pardon me. I had my decimal point in the wrong spot.

202:49:14 Parker: Understand .007. And was the...

202:49:20 Scott: Just - just put a zero in front of all - the three torquing numbers. The - the platform is too good and the numbers are so small we - we're not even thinking in three digits anymore.

202:49:29 Parker: Okay. We've got 007, 047, and 005. Understand.

202:49:36 Scott: That's correct. [Long pause.]

202:49:54 Irwin: Okay, Bob. I'm ready to copy the PAD.

202:49:57 Parker: Okay, Jim. It's TEI-69, SPS/G&N; plus 36245; plus 0.61, plus 0.92; 213:51:51.04; plus 2803.1, minus 0465.4, minus 0099.6; 179, 132, 353. The rest of the PAD is NA. Ullage; 4 jets, 12 seconds. Over.

[An interpretation of the PAD follows:

Purpose: This is the latest in a long series of PADs which detail how, in an abort situation, the crew can get home, even if communication with Earth is lost. In the unlikely event that the burn is required, it would occur towards the end of the 69th orbit.

Systems: The burn, if required, would be made using the SPS engine under the control of the Guidance & Navigation System.

CSM Weight (Noun 47): 36,245 pounds (16,440 kg).

Pitch and yaw trim (Noun 48): 0.61° and 0.92°. These are the angles for pointing the SPS engine bell to ensure its thrust acts on the spacecraft's centre of gravity.

Time of ignition, Tig (Noun 33): 213 hours, 51 minutes, 51.04 seconds.

Change in velocity (Noun 81), fps (m/s): x, +2,803.1 (+854.4); y, -465.4 (-141.9); z, -99.6 (-30.4). These velocity components are expressed with respect to the local vertical/local horizontal frame of reference.

Spacecraft attitude: Roll, 179°; Pitch, 132°; Yaw, 353°. The spacecraft attitude for the burn is expressed relative to the lift-off REFSMMAT.

Other items in the standard form are not applicable (NA) to this burn.

SPS propellants are settled in their tanks by firing the plus-X thrusters on all four quads around the Service Module for 12 seconds.]

202:50:50 Irwin: Okay. Readback for TEI is SPS/G&N...

202:51:03 Irwin: Are you reading me better? Bob, are you reading me okay?

202:51:08 Parker: You've got a loud squeal there, Jim, but I can probably read you.

202:51:16 Irwin: Okay, Bob. Here's the readback. SPS/G&N; 36245; plus 0.61, plus 0.92; 213:51:51.04; plus 2803.1, minus 0465.4, minus 0099.6; 179, 132, 353; 4 jets for 12 seconds. Over.

202:51:42 Parker: Roger, Jim; copy. Good readback. And, Endeavour, that's all we've got for you right now, until you give us a presleep call, except for standing by for a film budget report from Al. [Long pause.]

202:52:22 Worden: Houston, 15.

202:52:24 Parker: Go. Go, 15.

202:52:28 Worden: Okay, Bob. I've got that film thing compiled for you, if you want to copy.

202:52:32 Parker: Copying.

202:52:34 Worden: Okay. I will read you frames expended. Magazine Nectar 76, Oscar 58, Romeo 55, Victor 12. And I haven't used anything out of S, and L is running right now on the Mass Spec.

202:52:57 Parker: Roger; copy. 76, 58, 55 and 12. Thank you guys. Give us a call when you're ready for sleep and we'll tuck you in.

202:53:16 Scott: Okay, Bobby. Love to have you do that.

[Long comm break.]

[Flight Plan page 3-315.]

[One member of the crew is continuing to take photographs on magazine PP. AS15-90-12279 looks towards the western shore of Mare Fecunditatis under a nearly overhead Sun. The double rays sprayed across the mare surface radiate from a well-known pair of craters, the Messier Twins, named after the French astronomer, Charles Messier, 1730-1817, whose catalogue of fuzzy objects in the night sky has made his name synonymous with galaxies, nebulae and the amateur astronomer's desire to view as many of them as possible. The crater pair, actually known as Messier and Messier A, are very unusual in that both are quite oval in shape with their long axes aligned with each other and with the striking double ray seen in this photograph. It is almost certain that they originated in a most unusual, highly oblique impact, probably of a small double asteroid. It is known that a substantial number of asteroids are to be found in loose formation with one another, gently orbiting around their common centre-of-gravity. Left of centre and outlined in a light colour is Lubbock, a 14.5-km crater named after John Lubbock, 1803-1865, an English mathematician.]

[Lubbock is more to the foreground of AS15-90-12280, while beyond it and to the left is Gutenberg. Named after the pioneer of movable type and the printing press, Johann Gutenberg, 1398-1468, this 74-km crater's walls have been heavily intertwined with other large craters. The flooded Gutenberg E breaks up the foreground wall and the bright Gutenberg A punctures the far wall. Rather than having a central peak, Gutenberg's floor displays the beginnings of a central ring.]

[To the right of AS15-90-12283 is the exceptionally bright ray system of Censorinus, a small (3.8 kilometres) but highly visible crater which is considered by Earth observers as a useful landmark for timing the progress of lunar eclipses when the Earth's shadow slowly moves across the Moon's disk. It is named after a Roman astronomer, circa 238 AD.]

203:05:58 Parker: And, Endeavour; Houston. We'd like Pan Camera, Standby.

203:06:10 Scott: Okay, Bob. Roger on the Standby. [Long pause.]

203:06:28 Scott: Houston, the Pan Camera was on Standby.

203:06:31 Parker: Say again, 15.

203:06:38 Scott: I say - the Pan Camera already was in Standby.

203:06:44 Parker: Okay. We'll have them check again. [Long pause.]

203:07:10 Parker: Okay, Dave. What we'd like is Power, On, also Pan Camera Power, On, for 5 minutes.

203:07:24 Scott: Okay. Power, On.

[Long comm break.]

[The Panoramic Camera is being powered to move film through the guides and idlers to avoid it setting.]

203:11:47 Parker: And, Endeavour; this is Houston. We can go Pan Camera Power, Off, now.

203:11:54 Scott: Roger. Power, Off, now.

203:11:56 Parker: Thank you.

[Very long comm break.]

[With the crew's meal break finishing, their only major task remaining is to complete the pre-sleep checklist which includes chlorinating their water supply and dumping the contents of the computer's erasable memory to Earth for analysis. Other than that, the communications system is configured for the night and the switch settings for various subsystems verified.]

203:20:03 Scott: Houston, Endeavour. Did you get the E-Mod dump?

203:20:07 Parker: Stand by.

[Long comm break.]
203:27:31 Parker: Endeavour, Houston. It's not clear that we got it the first time. Why don't you give us another E-Mod dump again, please?

203:27:43 Scott: Okay. Coming down.

203:27:45 Parker: Thank you.

[Very long comm break.]
203:39:59 Parker: And, Endeavour; Houston. We [garble] at the LOS in about 2 minutes. Everything looks in configuration for sleep. We'd like to verify the Oxygen Heaters are Auto, Auto, Off. Except for that, you are Go for sleep and Go for LOS.

203:40:18 Scott: Okay; understand. And we're fixing to give you the presleep checklist, there. And we have a little unscheduled maintenance on our friendly water valve again. So we'll be about 10 more minutes, but it's under control. Same - same problem we had before.

203:40:33 Parker: Roger. And understand it's under control.

203:40:38 Scott: Yes, it's just - just the same thing worked loose again, and we're fixing it now.

203:40:47 Parker: Roger. We copy. You guys didn't strike a coral reef there, did you?

203:40:54 Scott: [Laughter] No, I don't think so. [Long pause.]

[On their way from the Earth to the Moon, the chlorination port of the spacecraft's water system began seriously leaking. See 061:12:44 for the full story. Soon after, people began searching the history books to make comparisons between Apollo 15's Endeavour and Captain Cook's H.M.S. Endeavour which did run aground on a coral reef two hundred years before.]
203:41:27 Scott: Okay. O2 hea - O2 - O2 heaters are going to Auto, Auto, Off.

203:41:35 Parker: Roger. Auto, Auto, Off.

203:41:39 Scott: Roger.

[Very long comm break.]
Public Affairs Officer - "This is Apollo Control. We've had Loss Of Signal with the spacecraft. Just before going around the corner, Dave Scott reported that they had, again, the problem that they experienced earlier in the flight, and had very quickly gotten it under control. It was a water leakage, coming from a diaphragm in the Lower Equipment Bay where the crew inject chlorine into their potable water system to maintain the purity of that system and the water there. And what, apparently, is happening is that a nut is working its way loose and allowing water to seep out from around the diaphragm, and the procedure to prevent the leak - or to stop it - is simply to take a Allen head wrench, which the crewmen have onboard, and tighten the nut down. And Scott reported they had done this. We would not expect to have any further conversations with the crew. They are now or will shortly be in their rest period. We'll be reacquiring in about 45 minutes. Prior to beginning the rest period we received a crew status report and Scott reported that they had all been eating their meals as scheduled and have been consuming plenty of water. And he said that everyone is in fine shape and ready for the EVA. At 203 hours, 47 minutes; this is Apollo Control, Houston."

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