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Return to the LM

Corrected Transcript and Commentary Copyright © 1997 by Eric M. Jones.
All rights reserved.
Scan credits in the Image Library.
Video credits in the Video Library.
Except where noted, audio clips by Roland Speth.
Last revised 18 January 2010.

[John and Charlie had planned to leave Station 9 at about the 5 hour 25 minute mark in the EVA. The EVA started at 142:40:00 and about 5 hours 50 minutes have elapsed. In his next transmission, Charlie is asking Houston to confirm that, despite the fact that they are about 30 minutes behind schedule, Houston will let them do the Station 10 activities which, as per LMP-18 and LMP-19, consist of a double core, a trench, and some penetrometer tests at a spot about halfway between the LM and the ALSEP site.]
MP3 Audio Clip ( 13 min 11 sec )

148:29:45 Duke: It's back to the LM. Right, Tony?

148:29:48 England: Rog. We going back to the ALSEP area.

148:29:51 Duke: (To do) Station 10? (Listens to Tony) Yeah. That's what...Stop 10, right? (Pause)

148:30:06 England: Okay, we'd like you to drive gingerly up to the ALSEP area there, and we're going to ask you to hold the end of that broken (heat flow) cable up in front of the TV and that will be the Station 10 parking area. And then you can do the Station 10 tasks down to the south - correction - up to the northeast (of the ALSEP).

148:30:29 Duke: Okay. You mean out by the mortar package?!

148:30:36 England: No, it'll be behind the mortar package. The task will be up to the northeast.

148:30:43 Duke: Oh, yeah, to the northeast. Okay. (Pause) That's my other northeast.

148:30:52 England: Right.

[As shown in AS16-113- 18379, the Mortar Package is about 10 meters NNE of the Central Station, so Charlie was correct at 148:30:29. What Tony is probably trying to say is that they should do Station 10 northeast of the Central Station but well beyond the mortar package, as indicated in Figure 6-13 in the Preliminary Science Report.]
148:30:54 Duke: Tony, I can't get over how hilly this place is. It's one hill right after the other. Or ridge.

148:31:04 England: It sounds like an outstanding place. Sure wish I were there.

148:31:12 Duke: Well, we wish you were, too, Tony. (Pause) Okay, pictures are going. Tony, you're not going to see much out the right side of my in-motion Hasselblad because of this DAC camera magazine effectively blocks out that part of the field.

148:31:41 England: Okay. We understand.

[Charlie's Hasselblad pictures taken during the first part of the drive are AS16-115- 18473 to 18481.]
148:31:44 Young: Boy, but I...(Pause)

148:31:52 England: As long as you have the DAC on, that sounds fine...

148:31:54 Duke: That thing's at 007.

[Charlie is probably referring to the bearing indicator.

When they arrived at Station 9, they were at a bearing/range of 007/2.6 and a map location near BP.8/77.7. Unbeknownst to the crew, the circuit breaker and switch changes they made at Station 8 and, possibly, here at Station 9 have disabled the Nav system. Consequently, the bearing and range won't change during the drive back to the LM. See the discussion following 148:44:48.]

148:31:54 England: ...Why don't you swing the DAC back and forth a little bit occasionally during the drive and get a side view.
[As Charlie discovers at 148:42:11, he didn't actually get the DAC turned on and, consequently, there is no coverage of the first half of the drive back to the LM.]
148:32:06 Young: Anybody that ever called this place "plains" - Cayley Plains - really didn't know what he was talking about. There isn't a plain around here.

148:32:13 England: Right. Understand. Just like F smooth.

148:32:16 Duke: Right.

148:32:18 Young: That's exactly right! FS smooth. I can't believe it.

[This is a reprise of a conversation John and Tony had at 125:08:43 during the drive back to the LM at the end of EVA-1.]
148:32:25 Duke: John picked the only flat place within a kilometer (of the target point) to land.

148:32:31 Young: Sure glad we didn't land on any of these slopes, I'll tell you that.

148:32:36 Duke: Look at Hidden (Valley)...I don't know what this big crater is over here. This one...

[Charlie may be referring to the feature labeled Eden Valley on the "Descartes EVA-I, II 1 of 2 map" at BX.5/72.5. Eden Valley shows up quite clearly in the pan camera frames taken from the Command Module. See Figure 5 in the Traverse Planning chapter of the Professional Paper. A comparison of Figure 23 in the Stone Mountain chapter and Figure 3 of the Central Region chapter indicates that they are currently at about the same elevation as the southern rim of Eden Valley and, if that is true, then he probably isn't seeing into the crater. Eden Valley is about 2 kilometers north of their current location.]
148:32:40 Duke: Tony, really, the ridges here...Now, we're looking off...We're now at 007. You just saw it in the...Well, you'll see it in the 16(-mm film). But off to the 2 o'clock from 007 at 2.6, at north heading; there's an old subdued crater that's probably 30 meters deep.
[Note that Charlie hadn't yet noticed that the bearing and range to the LM haven't changed since they left Station 9.]
148:33:06 Young: And how many meters around?

148:33:09 Duke: Oh, I'd say...

148:33:10 Young: 900 meters long.

148:33:12 Duke: No, not that much. But 300, anyway.

148:33:16 Young: Yeah, it's 300 meters across.

148:33:20 Duke: And it didn't even show on the map! (Pause)

[They have been driving for about 3.5 minutes and, at 10 km/hr, would be about 600 meters north of Station 9. The depression is probably the one between Station 9 and Sunset Crater in Figure 5 in the Traverse Planning Chapter in the Professional Paper. If so, Charlie's estimate of a 300-meter diameter is quite accurate. The center of the crater is near BR/79. This may be the feature shown in AS16-115-18482.]

[During our mission review, Charlie and I used the "Descartes EVA-II, 1 of 2" map to try to locate this feature. There is far less detail on that map compared with what can be seen in the pan camera photography taken from the Command Module. Nonetheless, Charlie was able to identify the depression.]

[Jones - "During the third Apollo 15 EVA, when Dave and Jim were driving toward the rille, they ran into two or three of these big, shallow, subtle things that hadn't been on the maps at all."]

[Duke - "Well, we did, too. This area was one of them. It's all so subdued and flat that it doesn't look like anything. This is probably what we're talking about; we're probably right in here (BR/78.8). And now you can see, as you look, it's probably these old, subdued craters right in here."]

[Jones - "Just to the south and a little bit west of Sunset Crater."]

[Duke - "Or we could be out in here. There's another one...See, the ridges are running sort of this way..."]

[Jones - "The ridge lines are going northeast/southwest. And then the two things you were pointing at: one of them's at about BR/78.8 and the other one's at about BP/78.8."]

[Charlie then tried to use the bearing and range figures in the transcript to check himself but then said, "But I think that the thing's been busted, so we're right around in here where Merriam is."]

[The center of Merriam Crater is at BQ.9/80.7, but what Charlie was indicating on the map was the feature west of Merriam and BR/79.]

148:33:23 Young: I tell you what it did show in.

148:33:25 Duke: What?

148:33:27 Young: Those low angle looks (laughing) that we got at the landing site.

148:33:28 Duke: Yeah, I'll say.

[Jones - "Is this a reference to pre-landing passes over the site?"]

[Duke - "Yeah. Uh-huh."]

[Jones - "As with the other J-missions, you used the Command Module engine to put you in the descent orbit before you undocked the LM. Right?"]

[Duke - "Yeah. I think our perigee was about 8 miles right over the landing site, and a couple of times we had the windows (facing) down, so we could see it. In that low sun angle, early on, before we landed, it gave you real distinct shadows. It was good."]

[The Descent Orbit Insertion was performed at 78 hours 33 minutes. Lunar Module separation came after a sleep period at 96 hours and then, because of concerns about the Command Module, the descent didn't start until 104 hours 17 minutes. As shown in Figure 2.3-1 in the Lunar Surface Procedures volume, the Sun rose at the landing site at about 78 hours.]

148:33:28 Duke: That fender was well needed, John. I'm being showered with...

148:33:38 Young: Yeah.

148:33:39 Duke: ...dust.

148:33:40 Young: Didn't mean to do that. So am I.

148:33:43 Duke: Okay, Tony, we're coming in an area that's not as (pause)...not quite as blocky. I'd say maybe 10 percent of surface is covered with cobbles (about 64 mm to 256 mm). Still same size. There's one big boulder that I just got a picture of.

148:34:05 Young: Buried.

[This boulder may be the one shown in AS16-115- 18483, although Bailey and Ulrich believe it is the boulder in 18486.]
148:34:06 Duke: It's just buried. 3 meter...And it's buried from...Well, it's buried all over. I was going to say it's mostly from wasting from upslope, but that's not true. (Pause) And, off to our right is the big crater. The big, deep, very subdued that just shows...I see no large rocks, no outcrops at all anywhere around there. All I do is see big boulders that are apparently part of this ray. The biggest one being 2 meters. (Pause)
[Photos AS16-115- 18484 to 18486 were taken during this part of the traverse.]
148:35:09 Young: I'm making 11 clicks (meaning km/hr), now, in this relatively smooth region. (Long pause)

148:35:28 Duke: Tony, it's a very old surface, apparently. Every crater here is very subdued, from the half-meter size up to the 4- or 5-meter size.

148:35:41 England: Okay. Copy that.

148:35:42 Duke: (The surface is) completely saturated (with overlapping craters). Here come a couple of angular blocks that you just got a picture of. They remind me of the one we sampled up there at Station 8. (Pause)

[These blocks are shown in AS16-115- 18487 to 18491.]
148:36:01 Duke: We're getting into an area now at 007, at 2.6 where it's more pebbly than cobbly, (the rocks on the surface) being 4 centimeters or so.
[Note that the bearing and range readings still haven't changed.]
148:36:16 Young: My...

148:36:17 Duke: Huh?

148:36:18 Young: My whatchacallit just fell off.

148:36:20 Duke: The SCB?

148:36:21 Young: No. Look and see if it's between my legs. Can you see over there? I can't see...I think it fell between my legs.

148:36:28 Duke: What thing?

148:36:32 Young: My (unused sample) bags.

148:36:35 Duke: Well, I didn't see it, John. We've got plenty of those.

148:36:37 Young: Got plenty?

148:36:38 Duke: Yeah.

148:36:39 Young: Okay. Wanted to know whether to go back or not.

148:36:42 Duke: I don't think it's worth it.

[Photo AS16-115- 18492 shows what may be some small, primary impact craters surrounded by regolith breccia or, as it is more graphically known, instant rock.]
148:36:46 England: Okay. And could we have a range and bearing, please?

148:36:49 Duke: Okay. We're at 007 at 2.6, and we can...

148:36:53 England: Okay.

148:36:58 Duke: ...see just the top of Orion.

148:36:59 England: Very good.

[By now, Houston has noticed that the LM bearing and range aren't changing.]
148:37:00 Duke: And that Nav system, Tony, has got us pointed right at it.

148:37:05 England: Outstanding. (Pause)

[Although most aspects of the Nav system aren't working, John hasn't made any big excursions east or west since leaving Station 8 and, consequently, the true bearing to the spacecraft hasn't changed appreciably. Unlike the bearing and range indicators, the heading indicator is working and, so, by driving on a heading of 007, John is still pointed more or less at the LM.]
148:37:13 Duke: These little...Here's really a glass-covered one right there. Little round...Looks like a bowling ball.
[Pictures taken during this part of the traverse are AS16-115- 18493 to 18501.]
148:37:19 Young: We're doing V-max now, 8 clicks - 9 clicks; because we're going up a real steep slope.

148:37:34 England: Okay. Do you have a amp (reading)?

148:37:45 Young: We're all on the battery 1?

148:37:47 England: That's right.

148:37:48 Duke: (Getting an amp reading) 40. (Answering John) Yeah.

148:37:50 Young: Okay...(Surprised) 40 amps! Yeah.

148:37:52 Duke: Yeah. (Pause) Okay, we just topped out on a rise, Tony; and we're going down into another swale. I can see Flag crater off at 11 o'clock, and we're heading 007. It (meaning Flag Crater)'s boulder strewn on the south side. (Looking at something else) Pointed straight ahead of us, between us and the Lunar Module at...Uh-oh.

148:38:22 Young: What's the matter, Charlie?

148:38:24 Duke: The range keeps still saying two six (meaning 2.6). I (don't) think it's working. Well, anyway...You better belay that range, Tony. It's been 2.6 for quite a while.

148:38:41 England: Okay. That's fine. We agree.

148:38:46 Duke: We can see the LM, though.

148:38:48 England: Okay. Fine.

148:38:49 Duke: Now we're going down in another 2- to 300-meter - maybe 500-meter subdued crater. That's really going to be a steep slope, if we go straight into it, but John is adroitly maneuvering around it.

[The 2.6-km trip from Station 9 to the LM takes a total of about 24 minutes and John's average speed for the trip is about 110 meters per minute or 6.5 km per hour the slow average speed is probably due, in part, to sightseeing and picture taken and, partly due to the rolling terrain. They have been driving for about 9.5 minutes and, if their average speed has been 6.5 km/hr, they may be about 1.0 km north of Station 9. If so, they are entering the depression just north of Sunset Crater and, as can be seen in both Figure 5 in the Traverse Planning chapter of the Professional Paper and Figure 1 of the Stone Mountain chapter, this depression is about 350 meters across.]
148:39:05 Young: I'm not going down that critter. (Laughs)

148:39:07 Duke: That is really steep. Look at that.

148:39:09 Young: Look at that hole in the bottom of it.

148:39:10 Duke: I know it. Tony, it's a subdued crater without any rim at all. It is sort of oblong...

148:39:19 Young: But look at that; (that) hole in the bottom has a ledge in it.

148:39:26 Duke: I know it. Tony, this reminds me of Big Sag. You know Big Sag on the map, west of North Ray. Then this whole area to our right...

[Although I have not found any feature named "Big Sag" on the Apollo 16 maps available to me, Charlie's use of the word "oblong" suggests the elongated feature oriented NW-SE just above the "R" in "North Ray" in Figure 2 in the Traverse Planning chapter of the Professional Paper.]
148:39:40 Young: (Possibly as the Rover climbs) Up. Up. Up.

148:39:42 Duke: Turn the (16-mm) camera around there. (Pause) I wish I could give you...(Pause) (Subvocal) I can't turn it around. Best I can do. (Long Pause)

148:40:11 England: Okay. Just going...

148:40:12 Duke: Tony, you remember those out in Hawaii...(Stops to listen)

148:40:14 England: ...by time and speed, you're about 1.2 kilometers (from the LM).

148:40:20 Duke: Okay. Then our distance and range is stopped.

148:40:23 England: Rog.

148:40:25 Young: Our distance is...Our bearing appears to be okay.

148:40:34 Duke: Yeah. (Pause) Okay, Tony, you remember out in Hawaii, at Kapoho where we saw those very small little sink-hole craters?

148:40:44 England: Rog.

148:40:46 Duke: This looks like a big one of those.

148:40:47 Young: The one down in the middle of that hole?

148:40:48 Duke: Yeah.

148:40:49 Young: I agree with you. That's what I was thinking.

148:40:52 Duke: In fact, the whole area does, looks like just a big slump. Something fell out the bottom. Because there's no rim to this thing at all, John.

148:41:01 England: Okay. It'd sure be good if you could swing the DAC over that way, if it's still running.

148:41:06 Duke: I can't get it over that way.

148:41:09 England: Okay.

148:41:11 Duke: It's running, but I don't have strength in my hands. Let John turn over that way and as he swings around, I'll give you a couple of pictures of it. Can you make a 360, John?

[Charlie has just invented the procedure known as an LRV pan, which he and John and, later, the Apollo 17 crew will use to good advantage. As John turns the Rover in a tight circle, Charlie will take a panoramic sequence. These pictures are AS16-115- 18503 to 18511. The "sink" is probably the feature in the center of 18505. It is possible that the sink is the dark area about 4 crater diameters north of Sunset Crater.]
148:41:27 England: You should be out of film in the DAC.

148:41:29 Young: Okay, where do you want? Right here?

148:41:32 Duke: (To John) Yeah. Okay, that's fine.

148:41:34 Young: Did you get it?

148:41:36 Duke: Yeah. Could you keep on going around?

148:41:38 Young: Sure.

148:41:39 Duke: Let's just make a 360 this way.

148:41:41 England: Okay, and get it on your Hasselblad, please.

148:41:44 Young: Hey, that's a neat way to...(Stops to listen)

148:41:48 Duke: Okay, that's what we're doing.

148:41:49 England: Good show.

148:41:50 Young: That would be a neat way to take a pan, Charlie.

148:41:52 Duke: That's just what I'm doing, taking a pan of that thing. Okay, we got it!

148:41:57 Young: Okay.

148:42:00 Duke: Great. (To Houston) Okay, we got a pan from the Rover, Tony, with a 360.

148:42:03 England: Okay. And if you can turn the DAC off...

148:42:05 Young: Were you able to change the settings?

148:42:07 Duke: Yep.

[As they go around in a circle, the lighting changes and Charlie has to adjust his f-stop setting.]

[Each of the film magazines has a decal on the top which shows recommended f-stop settings for aiming directions relative to the Sun.]

148:42:07 England: ...please turn it off.

148:42:11 Duke: (Answering Tony) Okay, wait a minute. Well...(Pause) Apparently it wasn't running, Tony, because I've still got half a mag left. I'll turn it back on.

148:42:30 England: Okay. (Pause)

MP3 Audio Clip ( 9 min 46 sec )

148:42:36 Duke: My arms are just too short...

148:42:39 England: Understand.

148:42:40 Duke: ...to get that thing on and off from the Rover seat. I should have turned it on the side (before mounting the Rover at Station 9), but at 12 frames a second I thought we'd just run too much out. Okay, it's running now.

148:42:53 England: Okay.

148:42:57 Young: I could tell you how it's doing, Charlie. I could glance at it ever (sic) so often. (Long Pause) (To Houston) Sure is comforting be able to hear those old wheels turning. You can hear them; they make a rumble.

148:43:20 England: We can't hear them, but we can imagine it's comforting.

148:43:22 Duke: A walking traverse in this place would be terrible. (Pause)

[Jones - "I hadn't ever noticed that statement of John's before. Could actually feel the..."]

[Duke - "I think what you felt was the vibration, the hum of the electric motors and the wheels turning, and the bearings. And that electrical motor vibration fed into the seat; and I think what you felt was that vibration, which translated into a sound. A low pitched sound. A little rumble. It (meaning the seat vibration) translated into the suit and, then, the atmosphere in the suit gave you a sound."]

[Jones - "I don't know if we've talked about walkback in the case of a Rover breakdown. Was there much detailed planning for that?"]

[Duke - "The only thing I can remember is, based on our terrain, they wanted to limit us to maybe 6 (or) 7 kilometers."]

[Jones - "Out and back? Or one-way?"]

[Duke - "One-way. If the Rover didn't work at all and all we could carry is what we could get in our hands - that's why we had the little tool carrier - I think we were limited to about a kilometer. We had some contingencies."]

[Generally, walk-back constraints for the Rover missions were built on the assumption that, over distances of less than one kilometer, the crew could maintain an average speed of 3.6 km/hr while, on longer trips, the average speed would be 2.7 km/hr.]

[After some searching, Charlie found maps for the planned walking traverses.]

[Jones - "On EVA-1, they had you going out to Buster."]

[Duke - "Yeah, we went out to Buster, which was...This is 200 meters. (Counting) So it's about 800 meters. And then this one (EVA-3, to the north), they were going to have us go out (counting) two kilometers..."]

[Jones - "Out to End Crater."]

[Duke - "Yeah. And, down south, was going to be quite a walk. I don't think we ever would have made it down here. But (counting) it was about 3 kilometers."]

[Jones - "They got you going down as far as BL/81.5. down about as far south as Wreck. So, basically, on the first one they had you go to Buster and then, on the second one, to the foot of Stone Mountain and then going up and looking at Palmetto on the third one."]

148:43:28 Duke: Okay, still in a cobbly area, Tony. There're two...Apparently...To me there are two distinct sizes. Those are the 6-centimeter size and below - well, around 6 centimeter - and those around 15 centimeters. Cover 30 percent of the surface.
[The pictures Charlie took during this part of the traverse are AS16-115- 18512 to 18525. Frame 18521 is an example of a cobbly area.]
148:43:55 Young: Okay, I'm V-max right now, Houston, and up slopes we're going about 8 (km/hr) and down slopes about 11.

148:44:06 England: Good.

148:44:08 Duke: The Nav system is gone completely, John. That bearing's not even working, I don't think.

148:44:17 Young: Huh?

148:44:18 Duke: I don't think that bearing's working either. (Pause) Could our bus configuration cause...? (I) don't see how.

148:44:30 Duke: What does the Nav system work off of, Tony? Is it Batt 2?

148:44:39 England: Stand by a second, Charlie.

148:44:41 Young: Betcha it is. That's the LM up there, isn't it?

148:44:47 England: Okay. ...

148:44:48 Duke: Yeah; it's straight ahead of us, but it's over that next ridge.

148:44:48 England: ...Your Nav system works off Baker and Delta, so it should be on Baker, all right.

[As indicated in Figure 1-22 in the LRV Operations Handbook, Bus Baker supplies power from Battery 1 and Bus Delta supplies power from Battery 2. Charlie suspects that the switch changes they made at Stations 8 and 9 may have caused the problem. He is probably on the right track. The following discussion is taken from the Apollo 16 Mission Report. Unfortunately, this is one of the poorest analyses to be found in any of the Apollo Mission Reports.]

[Apollo 16 Mission Report - "After leaving Station 9 during the second EVA, the crew reported that the computed parameters of bearing, distance, and range were not being updated by the Navigation system. The heading and speed indicators, however, were operating normally. In reviewing the navigation data reported at Stations 8 and 9, the distance and bearing data are incompatible with the time and direction of travel, respectively, from Station 8 to Station 9. The readouts (at Station 9) had the bearing and distance indicating a northeasterly direction (of travel from Station 8), although the crew reported that travel was in a northerly and northwesterly direction. This indicates the Navigation system also failed to operate properly between Stations 8 and 9."]

["At Station 8, after the navigation readouts, the vehicle was moved while attempting to determine the cause of the rear-drive loss between Stations 6 and 8. Several switch configurations were attempted, which (probably) accounts for the subsequent incompatible navigation readouts at Station 9."]

[The next paragraph explains why the heading and speed indicators worked properly.]

[Apollo 16 Mission Report - "The Navigation system is functional with the Bus B (Battery 1), Bus D (Battery 2), and Navigation circuit breakers closed. In this configuration, the gyro operates and the heading is displayed. In addition, with the right-rear motor-drive-power switch to either Bus B or Bus D, the speed indicator will register. In order to compute and display distance, bearing, and range data, and to update these data, at least three of the four motor-drive-power switches must be positioned to an active bus."]

[The next paragraph discusses possible reasons why the Nav system stopped updating on the drive from Station 9 to Station 10.]

[Apollo 16 Mission Report - "The crew reported that the Navigation system was not updating bearing, range, and distance. This condition will occur with the loss of power to two drive motors. From the battery and motor temperature data in Figure 14-80, the Battery 1 temperature shows an increase while the Battery 2 temperature did not rise, indicating little or no load on Battery 2 (a fact which is not surprising given that all of the motors were switched to Battery 1 before leaving Station 9). Also, the rear-motor temperature shows an increase while the forward motor remains constant. Thus, the Navigation (system) had no inputs from the forward wheels and could not update."]

[The observation about the forward motors seems to be the relevant one, although one would expect that John would have made a comment if he'd thought he didn't have forward drive power.]

["At Station 10, the digital displays and internal registers were reset to zero and the circuit breakers and switched were returned to the normal configuration. The Navigation system then performed normally throughout the third extravehicular activity."]

148:44:57 Duke: Okay. Well, it's not counting either range, bearing, or distance.

148:45:05 England: Okay. Is your heading working at all?

148:45:08 Young: The bearing's working, isn't it?

148:45:10 Duke: I don't think so. (Responding to Tony) Yeah, the heading's working. (Long Pause)

148:45:25 Young: I'll tell you how we'll get back, Charlie.

148:45:30 Duke: Yeah, we got to go on top of that ridge over there, and then we'll be there. John, see those blocks up on the top of Smoky?

148:45:37 Young: Yep.

[John may have turned to the east at this point, as shown in Charlie's photo AS16-115- 18526. Photos taken during the next part of the drive are AS16-115- 18527 to 18540.]
148:45:38 Duke: If you head for those, the LM was right in line with those from our last stop. And I'm convinced that bearing was good from our last stop (and) we haven't changed much. (Pause) Okay, Tony, coming up into the area now to our 3 o'clock position - correction 9 o'clock [and] we're heading 020 - it looks like another one of those old subdued, sag areas.

148:46:09 England: Okay...

148:46:10 Duke: "Burrows", let's call them.

[Duke - "When a mole crawls under your yard, he makes a mound (as he tunnels). Then, once he leaves and it rains real hard, that soil continues to go down and it fills that burrow that he's dug out - that tunnel - and it just sags in from the top."]
148:46:10 England: ...And we're going to cut back on our Station 10 just a little bit here, and we'll skip that (TV) photography of the heat flow cable. We'd like you to park halfway between ALSEP and the LM, and do a nominal station 10, except we'll drop the trench.
[The Station 10 activities are shown on CDR-18 and CDR-19.]
148:46:27 Duke: John...

148:46:28 Young: Don't want to do the trench. Okay.

148:46:29 Duke: John, you lucked out.

148:46:30 England: Yeah, I bet that breaks you up.

148:46:35 Young: Surprises me. (Pause)

[Trenching is a physically difficult task and, during Apollo 15, Jim Irwin made frequent references to the fact that he was not looking forward to his trenching tasks as part of Station 8.]
148:46:44 Duke: How do the consumables look, Tony?

148:46:46 England: Your consumables are fine.

148:46:51 Duke: Rog. We feel fine.

148:46:53 England: Okay. Good.

148:46:56 Duke: Okay. We're coming up on an area now, as we top a ridge, that is bouldery. About 10 to 12 percent of area is covered with boulders greater than 50 centimeters. And then it's cobbly, covering about 60 percent. Looks like, apparently, a secondary around here somewhere caused all this. But we don't see the crater.

[Charlie's photo AS16-115- 18541 probably shows this area. Frames 18542 to 18547 cover the next part of the traverse.]
148:47:23 England: Okay, we copy that, and you have enough consumables to go on a long time. We just feel you've put in a good day.

148:47:33 Young: Well, why don't we stay out here and set a new world's outdoor record?

[The second Apollo 15 EVA lasted 7 hours 12 minutes 14 seconds and was far longer than any of the EVAs conducted by prior crews. The first Apollo 16 EVA was just slightly shorter at 7 hours 11 minutes 2 seconds. John and Charlie started EVA-2 at 142:39:25 and are currently 6 hours 8 minutes into it.]
148:47:37 England: Ah, we don't need that; we got to leave...

148:47:39 Young: You don't want to do that, huh?

148:47:39 England: ...something for 17. (Pause) We're going to set a new sleep record on this one.

[Prior to Apollo 16, heart-rate data recorded during the rest periods indicated that no one had gotten more than 5 to 6 hours of sound sleep. According to the Apollo 16 Mission Report, "this was the first mission in which the lunar module crewmen obtained an adequate amount of good sleep while on the lunar surface. The estimates of sleep duration made by ground personnel were in general agreement with the crew's subjective evaluations." John slept soundly during all three rest periods. "Typically, the Commander's sleep was uninterrupted for 4 to 5 hours, after which he would awaken, get a drink of water, and return to sleep for the rest of the night."]
148:47:44 Duke: Well, this has been fun. There's that secondary. (Listens to Tony) Okay, there's the secondary, Tony. We're coming up...On our 2 o'clock...(correcting himself) 10 o'clock position, there's about a, what, 50 meters, John, you think?

148:47:56 Young: Yep.

148:47:57 Duke: Fifty-meter crater that's a secondary; or, at least, it might be a primary, with these blocks just being out of it. And it's quite deep. (Pause) That's probably a prim...I don't know whether that's a secondary or primary, though. (Pause) We could tell. The block distribution seems to be (pause) radially equivalent (means "symmetric"). I think that was probably a primary punched into the old Cayley. (Pause)

[Primary crater is dug by an object coming in from space. The typical impact velocity is 20 km/sec and the resulting crater is usually symmetrical. A secondary crater is caused by the impact of a piece of ejecta from another lunar impact. The impact velocity is necessarily less than the lunar escape speed of 2.4 km/s. Secondary craters are often oblong in shape and, if the impact velocity is low enough, pieces of the impacting object will be evident in the crater or its immediate vicinity.]

[Jones - "Was it easy to distinguish primary craters from secondary craters. "]

[Duke - "No, it wasn't."]

[Jones - "South Ray was quite recent..."]

[Duke - "They felt it was quite recent because it was white, and North Ray the same way. Recent (primary) craters had the distinct rim, whiter albedo and angular blocks. The older ones were the more subdued (with) the rounded rims, lack of distinct blocks, and a very dark albedo. I think that's how they judged, looking at the photographs that we had. Whether that was accurate or not, I don't know."]

[Jones - "And, as you were driving around..."]

[Duke - "It was very difficult. Especially...Well, I mean, like the old ones, the old, sagged areas - we called 'em sags - those were probably old craters because the rims were just gone and there was no big, real angular blocks. This one was sort of hard to tell whether it could have been a secondary (that) a big block pounded or whether it was a primary where a big meteorite hit and then blasted out the rocks from the basement onto the side. Now, that's what North Ray was (namely, a big primary). Now, if this one was a primary, it wasn't a recent one, because the albedo was darker. Now, North Ray, we knew that was a primary. This one is a smaller one - 50 meters - and whether it was a primary or a secondary it was tough to tell."]

[Jones - "Because you did have a lot of secondaries around, from South Ray."]

[Duke - "And North Ray, probably."]

[Jones - "The 17 guys, as they were driving along, kept seeing what they described as little, glass-lined, pit-bottomed craters..."]

[Duke - "We saw some of that. The real small ones were that way."]

[Jones - "A meter or so across."]

[Duke - "Uh-huh."]

[Jones - "Real fresh with some glass in the bottom."]

[Duke - "A little crater and it would look like a glass blower had poured out liquid glass and it just puddled in the bottom. We saw some of that. We saw some of that glass dripped - like sauce on a sundae - just over the rock. We saw quite a bit of that."]

[Most of these are probably primary craters created by very high-velocity impacts, rather than secondaries dug by pieces of ejecta coated with still-molten glass.]

[The fact that Charlie describes this crater as being radial symmetric and relatively deep suggests to me that it is a primary, albeit one old enough that the soil ejecta has been darkened by the steady rain of very small impactors.]

[In 3.5 minutes, John will report that they are about 200 meters from the LM. Assuming an average speed of 9 km/hr, we can estimate that this steep-side, 50-m-diameter crater is about 700 to 750 meters south of the LM. An examination of Figure 3 in the Central Region chapter of the Professional Paper shows a deep, 40-m crater 680 meters from the LM on a south southwesterly azimuth (north = 0) of 192.]

148:48:40 England: Okay; and, Charlie, we think the DAC's out of film now, if you want to turn it off.

148:48:45 Young: It is empty. Reading empty.

148:48:48 Duke: Okay. (Pause) Okay, it's Off.

148:48:52 England: Okay.

148:48:53 Young: What's that thing up there on the hill, Charlie?

148:48:58 Duke: Where? Straight ahead?

148:49:00 Young: Yeah.

148:49:02 Duke: That's a rock.

148:49:03 Young: I was afraid you were going to say that.

148:49:04 Duke: We got to get over this ridge, John, and we'll see the old LM. (Pause) Man, I am covered from head to foot! With dust. (To Houston) Boy, those fenders really are useful, Tony. This one we lost in the back has resulted in us being...

148:49:35 Young: Pretty dirty.

148:49:36 Duke: ...a Double Pig-Pen.

148:49:38 Young: We're going to have to really brush.

148:49:40 England: Charlie, you mean you guys are getting dirty?

148:49:42 Young: Maybe that's how we'll get our extension.

[John really wants the EVA record and is suggesting that they'll have to stay out so long dusting each other that they'll get it.]
148:49:47 Duke: Nah. Been dirty. (Pause) I think we're going to probably come out a little east of where we need, John.
[As Charlie indicated at 148:45:30, he is estimating their position by sighting on some blocks on Smoky Mountain.]
148:50:03 Young: I wouldn't be surprised, Charlie.

148:50:08 Duke: But if we do, we ought to cross the (outbound) tracks if we get too far east.

148:50:09 Young: That's exactly why I'm going this way, old buddy.

148:50:11 Duke: Okay.

148:50:12 Young: Hang in there.

148:50:14 Duke: You are sharp!

148:50:15 Young: Yez.

148:50:17 Duke: You full blower (meaning full throttle)?

148:50:19 Young: V-max.

148:50:21 Duke: Must be a pretty steep slope here. Man, look at those angular blocks there, would you. Around there. (To Houston) Tony, here are 30 or 40 very angular blocks - 50 centimeters or so. And they have the same character as the ones we sample back (along the traverse), so (it's) apparently ray material.

148:50:46 England: Okay.

148:50:48 Duke: A little comment about the regolith. The regolith is texturally the same throughout. The only difference is the difference in albedo that you can see on some of the fresh craters and also in the rays as we were going towards South Ray. (Pause)

148:51:15 England: Okay. And, Charlie, you can expect the feedwater tone.

[The PLSSs each contain two feedwater containers and Charlie's main tank is just about empty.]
148:51:18 Young: Truly an amazing vehicle.

148:51:19 Duke: Isn't it?

[Charlie's feedwater tone can be heard in Houston.]
148:51:22 Duke: Okay, I just got a flag of some sort.

148:51:25 Young: Or is that me?

148:51:26 Duke: Huh?

148:51:28 Young: Is that you or me? You expecting a flag, Houston?

148:51:35 England: Right. Can you...

148:51:37 Duke: I got a water flag.

148:51:37 England: ...reach (your) Aux water on the Rover?

148:51:40 Young: Houston. (Pause)

148:51:45 Duke: Houston.

148:51:46 England: Go ahead, Charlie. (No answer)

148:51:51 Duke: Okay, I'm going to Aux Water, On. There's the LM, John.

148:51:57 Young: How about that, sports fans.

148:51:59 Duke: Right on, babe. Right on. (Pause)

[As can be seen in AS16- 115- 18547, John is aimed right at the LM, a testament to the value of using horizon features to steer by.]

[Frames 18548 to 18550 show more of the approach.]

MP3 Audio Clip ( 5 min 15 sec )

148:52:05 Young: Okay, Houston, we just topped the ridge, and the LM is (chuckles) about 200 meters from us. (Pause)

148:52:14 Duke: I think we've had a comm drop. (Pause)

148:52:23 England: John, Houston.

148:52:27 Young: Go ahead.

148:52:30 England: Okay, we had our comm drop out here, and I understand Charlie got his water switched over?

148:52:37 Duke: That's affirmative.

148:52:38 England: Okay.

148:52:39 Young: Yeah, Charlie's on Aux water.

148:52:42 Duke: Were you expecting that? .

148:52:43 England: Yeah, we tried to give you a call, but we had our comm drop out just about that time. (Pause)

148:52:55 Duke: (To Houston) It is! (To John) How about swinging right and let me get a picture of that, John. With the Rover (means the LM) and...a little bit more.

[Charlie was asking John to turn a little to the right so he could take AS16-115-18551.]
148:53:06 Duke: We want a nominal Station 10, so it's between the core...
[As indicated on LMP-18, they are planning to do Station 10 midway between the ALSEP site and the LM. John turns toward the ALSEP and Charlie takes AS16-115- 18552 and 18553. Frame 18554 is blank. As is shown in LMP-19, Charlie had planned to drill the deep core east of the Central Station but, as is shown in Figure 6-13 in the Preliminary Science Report, he actually drilled it on the south side.]
148:53:09 England: Charlie...

148:53:10 Duke: If we stop over here to the right by that...(Stops to listen)

148:53:10 England: ...your feedwater pressure's still building. (Pause) Okay, we've got it now, Charlie. Your feedwater pressure's going up.

148:53:23 Duke: Okay, I was on Min (feedwater flow).

148:53:25 England: You're in good shape.

[When Charlie's main feedwater supply went dry, he began to lose the ice layer in the sublimator in his PLSS and, consequently, the feedwater pressure began to drop. Once he switched to the Aux tank, the ice layer began to build up again and the resistance it provided led to an increase in the feedwater pressure.]
148:53:28 Young: (Lost under Tony) between the mortar package and the Rover (means the LM)?
[As is shown in Figure 6-13 in the Preliminary Science Report, the Mortar Package is the ALSEP component closest to the LM.]
148:53:33 Duke: No...(Reconsidering) Yeah, that's a good place to park. I've got to go over here and get the penetrometer in line...Yeah, that'd be good. Mortar package and the Rover (means the LM).

148:53:45 England: Sounds good to us. (Long Pause)

[As shown in LMP-19, Charlie plans to do a number of penetrometer tests on a line extending 50 meters east from the ALSEP.]
148:53:59 Duke: We won't have any trouble navigating without that Navigation system, but it's just keeping them posted to where we are.

148:54:05 England: Right. When...

148:54:07 Young: Yeah, that's what I think is so great.

148:54:07 England: ...you get parked there, we'd like you to reset your Nav.

148:54:11 Duke: Okay.

[Charlie is saying that the main benefit of having a working Nav system is that it lets Houston know where they are at any moment.]
148:54:13 Young: Okay. Which way we want to park on this one, Charlie?

148:54:15 England: 180 (as per CDR-18).

[Note that John's checklist is on his left arm and, to turn the page, he would have to take his right hand off the handcontroller. Rather than do that, he simply asks Charlie.]
148:54:16 Duke: Pointing south again. 180. Hook a right. (Pause) I can't believe how hilly this place is. There's not a flat place around!

148:54:27 Young: Right, except where that LM is.

148:54:29 Duke : Except right there where that LM is.

148:54:32 Young: It's really good. That saved us a lot of time. (Pause)

[Jones - "What does John mean by 'that saved us a lot of time'?"]

[Duke - "Well, if the LM was on a slope, we'd have had a very difficult time working. If you were coming straight down at a slow rate of descent, it could land on a 14-degree slope and stay upright; but that would have been a bitch to work on."]

[Jones - "Getting the equipment out..."]

[Duke - "You know, if it's pitched up on a slope (perhaps because the aft footpad is in a crater), you could have been alright in the front but, around to the back, I would probably not have been able to reach the Experiments packages. And it really would have complicated our setup of the Rover. So that's what he was talking about."]

[Jones - "Would it have complicated life in the spacecraft, too?"]

[Duke - "Well, I think we could have been alright. John could have slept with his head up (at the forward end of the cabin), and I could have rolled around against the bench back there. I'd have been alright."]

[Jones - "But if you had to lean one way or the other in the suit..."]

[Duke - "It wouldn't have mattered. No, you could have worked okay."]

[John has come to a stop with the Rover pointing south.]

148:54:43 Duke: (To Houston) Okay, it (meaning the Nav system)'s resetting, Tony.

148:54:45 England: Okay. (Pause)

148:54:51 Duke: Okay, and the heading says we're at 176, 65. What's the...I can't read the (Battery) number 2 Amp Hour.

148:55:07 Young: Number 2 Amp Hour is reading as 110.

148:55:13 Duke: Yeah. (Battery 1 is) 65 and (Battery 2 is) 110; (battery temperatures) 110 and 120; (motor temperatures) off-scale low, off-scale low; and off-scale low, off-scale low.

148:55:30 England: Okay, we copy that.

148:55:32 Duke: Wait a minute. The forward motors are not off-scale low; they're just coming up. Make that the rear motors; they're about 210.

148:55:43 England: Okay, 210. And we'll need EMU checks.

148:55:47 Duke: The forward motors are off-scale low.

148:55:48 England: Okay.

148:55:49 Duke: Okay, let me get out of this thing.

148:55:51 Young: Okay, mine is holding pressure at 3.95; I'm between Minimum and Intermediate (cooling). I don't have any flags and (pause) my O2 is so covered with dust, I can't tell what it is. (Pause) But it looks like...Hmmm. (Pause)

148:56:25 Duke: Tony, I think I got...(Pause) Dadgummit. (Pause)

148:56:34 Young: I can't tell.

148:56:35 England: That's okay, John. We read 35 percent down here.

148:56:38 Duke: Well, I got...

148:56:42 Young: Okay, Yeah. It looks up above 25, anyway. 25, 35. There you go.

148:56:47 Duke: That's what mine is, too, Tony, about 33. And I('ve) got 3.8, Min cooling, and I've got just a water flag. And the Aux water's on.

148:56:59 England: Okay, sounds good. [Pause]

148:57:04 Duke: Look at this place (probably meaning the area around his seat). It is filthy.

Journal Home Page Apollo 16 Journal Index Geology Station 10 near the ALSEP Site