MP3 Audio Clip ( 12 min 01 sec )
121:44:35 Scott: Okay, Jim, here we go.
121:44:37 Irwin: Okay, Dave. We want a heading of 203.
121:44:44 Scott: Okay, 203.
121:44:45 Irwin: (To get to) Checkpoint 1.
[Jim is probably looking at Part A of the EVA-1 and EVA-2 traverse map. Checkpoint 1 is at the edge of the rille near Canyon Crater. Had they landed at the planned spot, a drive of 2.0 kilometers on a heading of 203 would take them to the checkpoint. They are, of course, about 600 meters north and about 175 west of the planned landing site but don't know that.]121:44:49 Scott: Going to miss that double Ackerman (front and rear steering), I can see that now.
121:44:55 Irwin: Okay, we're moving forward, Joe.
121:44:57 Allen: Roger. (Pause)
[Irwin - "Each wheel (pair) is on an individual axis, separate axis. Each wheel (pair) steers on its own radius, so it's independent steering. And it's referred to as double Ackerman. Optimum steering. I don't know whether Honda has that in their four-wheel steering or not. Double Ackerman; It's been so long since I used that word."]121:45:02 Scott: Whew! Hang on.
121:45:06 Irwin: And we're coming around left. (Pause)
121:45:16 Irwin: Heading directly south right now to miss some craters off to our right - very subdued craters.
121:45:24 Scott: Okay, I'm going to take a little zigzag here...
121:45:26 Irwin: On the right is...
121:45:28 Scott: Hang on. Get a feel for this thing. Nine kilometers an hour, Joe. (To Jim) Hold the geology; let's get the Rover squared away first. (Pause) Okay; 8 kilometers (per hour) up a little rise. Okay, turning back. (Pause) 203, huh? Okay.
[Irwin - "It seemed like we were going much faster."]121:45:57 Irwin: (Heading) 203 for 2 miles (means kilometers).
[Jones - "Because of the roughness of the terrain?"]
[Irwin - "I guess so."]
[For comparison, as a 'fitness' runner, your editor once upon a time managed an unimpressive 10 km/hr over 5 km. A world-class marathon runner maintains a speed of 20 km/hr over more than 40 km, albeit on a smooth surface.]
[Early in 2000 I found the following in Stephen Ambrose's marvelous biography of Meriwether Lewis, Undaunted Courage. During the spring of 1803, Lewis made an extended trip out of Washington to secure necessary stores for the proposed exploration of the Missouri and Columbia rivers and to be trained in celestial navigation and other essential skills. Lewis spent nearly a month in Lancester, Pennsylvania, with noted astronomer Andrew Ellicott learning to use a sextant, chronometer, other instruments so he could determine latitude and, more importantly, longitude. Lewis then headed for Philadelphia to continue his education/training. "The ride from Lancaster to Philadelphia took him over the most modern highway in America, completed in 1795, made of broken stone, the country's first gravel road. Stage wagons were able to average five to seven miles per hour (8 to 11 km/hr) on it. Going that fast in a stage was a new experience for Lewis."]
[Scott - "On the Moon, perhaps the measure should be hummocks per minute or craters per minute, rather than km/hr. Eight km/hr may have seemed to be fast because of the many features going by each minute. It certainly did appear that we were going quite rapidly across the surface features."]
[Finally, Dean Eppler, who works on Advanced Planetary EMU Development in the ISS Payloads Office at JSC, writes in April 2003 about some field work he undertook in the Antarctic during the southern summer of 2002/3: "We got on the order of 10-15 direct line miles from camp at the farthest, with distances on the order of 20-30 miles for total traverse miles. The vehicles we were using technically could go faster than 12 kph, but in a lot of the terrain, the roughness kept our speeds down to the 12 kph range. I got my snowmobile occasionally up to 40 mph, but that was not an average speed. Glancing through my field notebook, I see moving averages on the order of 6-8 mph. I guess it doesn't matter what planet you're on, if you don't have roads, the going is slow."]
121:46:05 Scott: Okay. (Noticing a sharp rimmed crater) That's a nice, young, fresh one.
121:46:10 Allen: Dave and Jim, Houston.
121:46:11 Irwin: Speed's varying between 8 and 10.
121:46:15 Scott: Go ahead, Houston.
121:46:16 Allen: Roger. Our TV pan suggests, you can go straight for St. George Crater, and you'll find Elbow okay. And we're suggesting you omit Checkpoint 1. Rhysling Crater should be a good landmark along the way, and head 208. Over.
121:46:36 Scott: Okay. 208, Joe.
[From November Crater, where Houston thinks they landed, a heading of 208 would take them more or less directly to Elbow Crater. From the actual landing point, it will take them to the edge of the rille near Quadrant Crater, which is at BN.0/70.2 on the map Jim is using.]121:46:39 Irwin: Okay, we're doing 10 kilometers, now. Now we're heading uphill; when we head uphill, it drops down to about 8.
[Scott - "We're skipping the checkpoint to make up time, because we're so far behind time. They have probably been making their trade-offs - whether you want to stop at Checkpoint 1 or go straight to Elbow - and they probably concluded 'We're behind time, let's go straight to Elbow.'"]
[Jones - "So, by going 208, you're going a little more west than the planned 203. They think you're northeast of the planned landing site and you're actually north-northwest. And all of that combined is going to run you into the rille well north of where you're expecting to."]
[Scott - (Chuckling) "It's just like a little TV drama, right?"]
[Jones - "Absolutely. A little detective story."]
121:46:47 Scott: No dust, Joe, no dust at all.
121:46:49 Allen: Yes, sir. Sounds great. (Pause)
[Scott - "Somebody said we'd be driving in a cloud of dust, because of the dust being thrown up from behind. That would have been a big problem 'cause suits get dirty and you can't see, or whatever. So it was comforting to find out that there wasn't a problem. And that was a conscious observation, because of the (pre-flight) speculation."]121:46:54 Allen: And, Jimmy, we're standing by for amp readouts.
[Jones - "Of course, John and Gene both had to drive in dust, 'cause they both lost rear fenders; and they both spent a hell of a lot of time dusting their Rover batteries as a result."]
[Scott - "I think we did find out, later on, that we had the rooster tail, but it didn't throw it up on us."]
[Ron Creel has provided a summary ( 1.3 Mb PDF ) of the fender extension losses that occurred on all three Rover missions.]
121:46:57 Irwin: About 9 kilometers, now.
121:47:01 Irwin: Okay, amp readout is...Looks like 15 on 1. I can't quite see 2.
121:47:18 Scott: Okay, I guess...Could this be Rhysling right here, Jim?
[Rhysling Crater is named for the blind space poet in Robert Heinlein's classic science fiction story "The Green Hills of Earth". Joe Allen quotes from the story at 167:51:20 at the end of EVA-3.]121:47:21 Irwin: Probably is...This large depression off to our left?
[Jones - "Did you and Dave do much of the crater naming?"]
[Irwin - "Joe Allen did a great deal of it. We did a few of the craters right around our site. There was a Scott. There was an Irwin. There was a Matthew, Mark, and Luke. There was Index. But we thought that was a good thing for the Mission Scientist to do. And Joe's a very resourceful Ph.D. and he did a good job on that."]
121:47:24 Scott: Yeah. (Pause)
[They have only been driving for about 2 minutes and, at 10 km/hr, have only gone about 300 meters. The large depression to their left may be Last Crater. Rhysling is at BK.9/72.6 on Jim's map and is approximately a kilometer south of their present location.]121:47:27 Scott: Well, I can see I'm going to have to keep my eye on the road. (Pause) Boy, it's really rolling hills, Joe. Just like 14. Up and down we go. Oh, and this must be Earthlight, huh? Could that be? (Pause)
[Earthlight Crater is near BJ.5/75.5 and commemorates an Arthur C. Clarke science fiction novel. In the opening chapter of Earthlight, Clarke described a monorail ride across the Apennines near Hadley and then onward for about 900 kilometers to an astronomical observatory in the crater Plato on the northern edge of the Imbrium Basin. See the discussion following 143:26:57.]121:47:48 Scott: Boy, look at that; we're going to have to do some fancy maneuvering here.
121:47:55 Irwin: There's an elongate depression here (at about 73.2 and stretching from BL.8 to BM.6) before you get to Rhysling. I don't think we're to Rhysling yet...Rhysling ought to be about 1.4. We've only gone, (let's) see, 0.4 (kilometers).
[They landed at a north-south coordinate of about BS.4. Because successive named grid lines - BS and BR, for example - are 250 meters apart, they landed about 2.4 grid units or 0.6 kilometers above the top of Jim's map. Consequently, they have not yet driven onto the map.]121:48:06 Allen: Roger, Jim...
121:48:07 Irwin: Okay.
121:48:08 Allen: ...we think you're short of Rhysling now.
121:48:13 Irwin: Do you think that's probably Rhysling out about 11:00 o'clock to us, Dave?
121:48:17 Scott: Okay.
121:48:18 Irwin: Out about, maybe, 1 kilometer.
[Jim is using a Rover-oriented clock with 12 o'clock straight ahead. Rhysling is more or less due south of them and, if they are really on a heading of 208, could be the crater Jim is seeing at 11 o'clock. Rhysling is a relatively fresh, 150-meter-diameter crater and would be noticeable, provided it is not hidden by intervening terrain.]121:48:21 Scott: Yeah. Okay, Joe, the Rover handles quite well. We're moving at, I guess, an average of about 8 kilometers an hour. It's got very low damping compared to the one-g Rover, but the stability is about the same. It negotiates small craters quite well, although there's a lot of roll. It feels like we need the seat belts, doesn't it, Jim?
121:48:49 Irwin: Yeah, really do. (Pause)
121:48:54 Scott: The steering is quite responsive even with only the rear steering. It does quite well. There doesn't seem to be too much slip. I can maneuver pretty well with the thing. If I need to make a turn sharply, why, it responds quite well. There's no accumulation of dirt in the wire wheels. (Pause)
121:49:24 Allen: Just like in the owner's manual, Dave.
[NASA photo KSC-71PC-345 (scan by J.L. Pickering) gives an excellent view of the wire wheels on the flight Rover during stowage on the outside of the Descent stage.]121:49:26 Scott: Okay, we're heading right...(Stopping to listen to Joe) Yeah, man! Okay, I've got it on the wall here (that is, at full throttle) for a minute, and we're up to 12 (km/hr).
[Figure 1-11 from the Rover Handbook shows the handcontroller. By pulling the handle forward from the neutral position, Dave commands forward motion. The farther forward he positions the handle, the faster their speed. By pivoting the handle rearward from neutral, Dave can put the Rover in reverse. Left and right motions produce turns in those directions.]121:49:41 Irwin: As soon we head upslope, it drops off.
121:49:43 Scott: Yeah.
121:49:44 Irwin: Or, are you deliberately slowing down?
121:49:46 Scott: Yeah, I slowed down in order to get my feeling before we start sprinting.
121:49:50 Irwin: Oh.
121:49:51 Scott: Look at this little fresh one. Boy, look at that! Lots of very angular frags all over the thing.
121:49:58 Irwin: Yeah, we passed several of those.
121:50:02 Scott: Okay; I'm going to cut down to the south here, Jim.
121:50:05 Irwin: Yeah, that'd probably be best, because I think that's probably...Let's see, range (is) point 7. That's still not Rhysling. Shouldn't be.
[If they have maintained the average heading of 219 that Dave reports at 121:52:54, they have traveled south about 540 m (2.2 grid units) and west about 440 m (1.8 grid units). they landed near BS.4/73.3 and, therefore, are near BQ.2/71.5.]121:50:14 Scott: Whoa! Hang on.
121:50:21 Irwin: And we have a large subdued one at our 1 o'clock position, I'd estimate 50 kilometers (means "meters") wide.
121:50:35 Allen: Roger, Jim.
121:50:36 Irwin: [Range is] 0.8.
121:50:39 Scott: Okay, how we doing on the heading, Jimmer? (Pause)
[Scott - "I had to keep my eyes on the road. I couldn't look at the instrument panel. I had to be focused on where we were going, and that's why I asked Jim about the heading. Even though I can cross-check very quickly - from airplane experience, out the window and back - I remember that you had to focus, consciously, so much on where you were going, because it was so irregular and things happened so quick at eight kilometers per hour (or '60 features per minute!', as Dave commented in 1996) that I couldn't take my eyes off of where we were going - even for a second - to look at the instrument panel and make an interpretation of the direction. I relied on Jim to do that for me, and that's why he's giving the distances and I'm asking him for the heading. Which is a reason why you want another guy along with you."]121:50:47 Irwin: Okay, if we're heading right for Elbow...
["And that brings up something else. I've learned more about the Russian Rover. Lunokhod was built for a man. For the one guy who landed."]
[Jones - "Really!?"]
[Scott - "Yeah. We can talk more about that. Lunokhod was originally built for their one cosmonaut who was going to the Moon, and then they put a robot chassis on it when they decided not to send him. How about that, sports fans!?"]
[Jones - "Marvelous! The way I understand it is that, on their first landing, Leonov was going to go down and do a footprint; and it's my understanding that, on that initial mission, they were going to do an umbilical EVA. That is, not a backpack-supported, autonomous EVA."]
[Scott - "Yeah. I don't know the details of the initial mission, nor do I know when they were going to take the Rover. But, in the early 60's, they designed Lunokhod for a single person. And then, when they decided they weren't going to send people, they took that chassis and they put the robot on top of it."]
[Mark Wade has created a Web site containing descriptions of the Soviet Lunar Programs, including Lunokhod.]
[Scott - "And that brings up an interesting point when you start thinking into the future. Do you want a Rover for one person or two people? In thinking about it now, without making a lot of trade-offs, gee, it was nice to have another person along. Because you could get more done. I'd have to think through it to make all the trades, but I guess the system was right."]
[Jones - "I've been transcribing my sessions with Pete and Al and they said they were involved, for a while, with the Lunar Flyer and that Pete had great plans of being the first guy to be a repeat Commander (on Apollo 19 or 20) and to use the Flyer on the Moon."]
[Scott - "I wasn't aware of that one! I remember the Lunar Flyer."]
[Jones - "The Flyer was a one-man vehicle, was it not?"]
[Scott - "Yeah. It was a one-man vehicle, while it lasted. Until Max Faget shot it down real well."]
[Jones - "On operational grounds, or engineering grounds?"]
[Scott - "Operational. Well, both. That would have been adding a hazard to a hazard, in my opinion. That's like taking a whole new set of circumstances and requirements and putting them in a remote situation, untested and you have a third dimension - that is, you can fall down. I think the Flyer would have been a very hazardous exercise. Very hazardous. And I'm not sure what you gain from it. But, nevertheless, I remember a lot of debate on the Flyer."]
[Jones - "One of the things that Pete and Al talked about was that, according to Max Faget, the Flyer was marginal as designed. It was marginal that it would work at all. And, if you actually started to build the thing, you would get into safety issues that would add weight to it..."]
[Scott - "And I think he's absolutely right. I don't think we were ready for that. And I'd have to give it a lot of thought, even at this point. Why do you want to do that? You want to range farther? Sure. But you have to consider the benefits versus the hazards versus the cost. You want to go flying around the Moon, but we've never flown a thing like that without an atmosphere before. Going to run into lot of unknowns."]
[Jones - "Maybe when you've got a lunar base that's been there for a while, you can do some experimental stuff and fly around in the immediate neighborhood."]
[Scott - "Sure. You're all set up with your own R&D facility on the Moon to experiment with things. That's when you go do it. Goodness. It would probably be useful to do that kind of R&D. Probably not here."]
[Jones - "And probably not on Apollo 19 or whatever."]
[Scott - "(Chuckling) I don't think so."]
[Journal Contributor Brian Lawrence took note of Dave's statement that Lunokhod was originally designed as a manned vehicle and, during May 1997, dug into the literature and found a pair of post-glasnost articles by Andrew J. LePage entitled Ahead of Their Time: The Soviet Lunar Program of the Seventies which were published in the January and February issues of the Electronic Journal of the Astronomical Society of the Atlantic. The following extract is reproduced with permission from the author, who modified the initial paragraph in 1998 to incorporate updated information on the origins of the program. "What would one day become the Soviet Union's third generation Luna program had its beginnings in 1960 at OKB-1 under Sergei Korolev. Mikhail Tikhonravov and his team of engineers at OKB-1, who had designed and built the Soviet's first probes to the Moon and planets, were now interested in designing a rover that could remotely explore the lunar surface. But with the ever increasing demands on OKB-1 after the Soviet government had secretly sanctioned Korolev's manned lunar program, all work on unmanned lunar and planetary probes was transferred in the spring of 1965 to the Lavochkin Association which had just been placed under the direction of Georgi Babakin. Over the following years the original moon rover concept, designated E-8, was substantially modified and its mission changed to support the upcoming manned lunar missions by the Soviet Union."]
["The E-8 program initially had two components: The E-8 rover and the E-8LS orbiter. Both versions of the E-8 would use a standardized propulsion bus weighing about 1,100 kilograms (2,400 pounds) and carrying as much as 3,900 kilograms (8,600 pounds) of hydrazine and nitric acid propellants internally and in four jettisonable outboard tanks. This bus carried all the consumables for its KTDU-417 main engine and attitude control thrusters. It also was equipped with an astro-orientation system and other sensors needed to support its payload in space. The rover would be brought to the surface by a standardized bus fitted with landing legs, a pair of ramps, and other equipment required for descent such as a radio-altimeter. Once deployed, the rover would perform an on-site survey of a proposed manned landing area. It would also carry a radio beacon to guide the Soviet's Lunar Cabin (LK) towards a pinpoint landing."]
["The E-8LS orbiter's mission was to perform an orbital survey of proposed landing sites. Its propulsion bus would be loaded with less propellant than the lander version but it would carry more consumables, such as for attitude control, needed for its planned year-long mission in lunar orbit. The orbiter's primary payload was a modified wheelless E-8 rover equipped with high resolution cameras and other instruments to study the lunar surface and surrounding environment."]
["One of the more conservative mission profiles contemplated for the first Soviet manned lunar landing called for an E-8LS orbiter to be sent to the Moon by a Proton-D launch vehicle. Once in lunar orbit, the probe would produce detailed maps of potential landing areas. After a suitable landing site had been chosen, two more Proton-Ds would be launched each carrying an E-8 rover. After a one month survey of the area, an unmanned backup lunar lander, called the LKR, and an unmanned LOK lunar orbiter would be launched towards the Moon by an N-1 Moon rocket. After entering lunar orbit, the LKR would be guided to the surface by the E-8 rovers' radio beacons. Once on the surface, the rovers would locate and inspect the LKR to insure it was in good condition. Meanwhile, the unmanned LOK would secure additional photographs of this and other proposed landing areas and return to Earth with its cargo of exposed film."]
["The following month another N-1 would be launched from Baikonur, this time carrying a manned LK and LOK. The LK, with a single cosmonaut on board, would be guided to the waiting LKR by the rovers' radio beacons. Each rover was equipped with a small platform and a supply of oxygen for the cosmonaut. If a problem developed with the LK, the cosmonaut would ride on one of the rovers to the waiting LKR which could then be used to transport him safely back to the LOK orbiting above. Later versions of the rover could be used by future lunar explorers much as the American Apollo J Series' Lunar Roving Vehicle (LRV) was used starting in 1971."]
121:50:54 Scott: Pick a spot here, okay. (Pause) You really have to pick your way.
121:51:02 Irwin: Yeah. You're only about half way to Checkpoint 1. We shouldn't...What I thought was Rhysling was probably not Rhysling. Rhysling is a larger crater, and it's out at about 1-point...should be about 1.4 from the LM.
121:51:32 Allen: That's affirm, Jim. Right on.
121:51:34 Scott: Okay. (Pause) Whoa. Hang on.
121:51:42 Irwin: Bucking bronco.
121:51:43 Scott: Yeah, man. (Pause) You back off on the power, it keeps right on going. (Pause) The zero-phase lighting is pretty tough, Joe.
[When looking directly away from the Sun (the zero-phase direction), they can see virtually no shadows and that, combined with the lack of strong color and, most importantly, a general brightening due to a process called Coherent Backscatter, completely washes out the zero-phase view.]121:52:02 Scott: We're going to have to make sure we keep at an angle (to downSun). Once I look into zero-phase, it all looks flat. (Pause) There's a nice little round one-meter crater with very angular frags all over the bottom and the rims, and glass in the very center. About a meter across.
[Jones - "You're talking about zero-phase here but your average heading is about 210 (roughly southwest). So you must be going west to get around something."]
[Scott - "(The washed out area around) zero-phase is not (just) due west, it's probably plus or minus 20 degrees (that is, from roughly 250 to 290)."]
[Jones - "But you're doing a significant turn to get around something."]
[Scott - "Apparently."]
[I asked Jim about this in 1989; and he, too, was puzzled about zero-phase on what was a southerly traverse.]
[Jones - "Could he have been doing some wide swings around craters?"]
[Irwin - "I guess. He must have, 'cause that's the only way you get any zero-phase. That's probably what he meant. (Chuckling) It was rough-riding regardless of how well you could see."]
[All of the crews - except Armstrong and Aldrin - commented on these small, glass-bottomed craters. They are dug by small, high-velocity impactors which turn a quantity of soil into glass when they hit the surface. The angular fragments on the crater rim are probably pieces of "regolith breccia" or, more descriptively, "instant rock". Soil closest to the impact point is turned to glass; but, farther out, soil is compacted into a weak, rock-like mass.]121:52:27 Allen: Roger, Dave. And, Jim, as you come up on the rille, you may want to turn your 16-millimeter camera on.
121:52:37 Irwin: Yeah, when we get to the rille, we will, Joe. Can't see the rille at all from here. Still looking for Rhysling.
121:52:45 Allen: Roger.
121:52:49 Irwin: 1.1
121:52:54 Scott: Okay, right now our bearing is 039 for 1.1.
[The Rover navigation system gives a range to the LM (1.1 kilometers from their present position), a bearing to the LM (39 degrees east of north), and a distance traveled. Their average heading since leaving the LM is, of course, 180 + 39 or 219 degrees. These figures indicate that they have traveled about 850 meters (3.4 grid units) south and 700 meters (2.8 grid units) west since leaving the LM. This would put them near BO.9/70.6.]121:53:03 Allen: Roger.
[Scott, from a 1996 draft review - "Before the mission, we were not even sure the LRV Nav system would work at all. And here we are, plotting our exact position 20 years later!"]
121:53:04 Scott: Okay. (Laughs) Click. (Long Pause) Hey, Jim, give me...Well, I just have to drive around these craters; that's all there is to it.
121:53:28 Irwin: Yeah. We have a large subdued one on our right about 60 meters wide with several small ones in the center. By small, I mean about 10 meters in diameter.
121:53:47 Allen: Roger, Jim.
[Jones - "Do you have any feeling for how well you were judging distances and sizes? I know it was difficult."]121:53:50 Irwin: Boy, it really bounces, doesn't it?
[Irwin - "It was just a guess. (Chuckling) I'd be curious to know how accurate it was. It would be good to have a final plot of where we were, actually, and see what craters we were looking at."]
[Scott, from a 1996 draft review - "That is something to look forward to in our later years. Someday, I will use the Journal to go back!"]
[Jones - "Did your ability to judge sizes and distances get better after you'd been at Hadley at a while. Did it start to be less of a guess?"]
[Irwin - "Well, I thought I could estimate probably as well as I could on the Earth. And I don't know how accurate I'd be on the Earth! 'Cause, you know, during our training exercises we practiced estimating sizes of craters, depths of craters. Saying it's 60 meters wide, I don't know why I picked 60. It'd be better to talk in increments of 50 meters, so things would be 50 meters or 100 meters. A geologist would like you to be as accurate as possible. We talk about small, medium, and large and put some numbers associated with those. And I don't know how accurate we were."]
[Jones - "Were you taking still photos during this traverse, at all?"]
[Irwin - "No. You mean with the Hasselblad? We wouldn't have done that while we were moving. I don't think we ever took any still pictures as we were on the Rover. It's a shame that the movie camera wouldn't work"]
[Jones - "There's a little short stretch of it coming back on this traverse, I think."]
[Irwin - "Yeah, I was wondering if it was on this traverse or on EVA-2. It's not clear which EVA it was. It had to be EVA-2. Because, on this EVA, the face of Mt. Hadley was in the shadow."]
[Jones - "And got sunlit by 2."]
[Irwin - "Yeah. And you could see that (in the short sequence of successful 16-mm photography)."]
[Partly as a result of the 16-mm camera failure on Apollo 15, both Charlie Duke (Apollo 16) and Jack Schmitt (Apollo 17) took Hasselblad photographs spaced at 50 to 100 meters during their traverses. Each of the Hasselblad film magazines held about 180 frames. The longest drive made by any of the crews was the 8 kilometer trip made by the Apollo 17 crew from the LM to the base of the South Massif. If Jack Schmitt had taken a frame every 40 meters, he would have run out of film before they finished the drive. By taking pictures a bit less frequently, he was sure to have enough film and could then change to a fresh magazine once he and Gene Cernan had reached their destination. Good photographic coverage of the route would allow an accurate determination of where the crew drove and would give geologists plenty of information about the distribution and sizes of rocks and small craters. With the 16-mm camera running at 1 frame-per-second, and the Rover running at 8 km/hr, the average spacing of frames was a bit more than 2 meters. However, the much larger Hasselblad frame size more than compensated for the less frequent coverage.]
121:53:54 Scott: Well, I think there's sort of a...The rear end breaks out at about 10 to 12 clicks.
[That is, the back end tends to swing around if he tries even moderately sharp turns at such speeds.]121:54:04 Allen: Roger, Dave. It sounds like it's like steering a boat, with the rear steering and the rolling motion.
121:54:05 Scott: And, gosh, every (lost under Joe)...(Responding to Joe) Yeah, that's right. It sure is. (To Jim) Hey, here's a good fresh one right there...
121:54:15 Irwin: Yeah, I was looking at that one at 1 o'clock to us right now. Very fresh angular blocks of lighter albedo material on the south rim.
121:54:24 Scott: Okay, let's...
121:54:25 Irwin: We kick up a little dust when we go through these craters.
121:54:28 Scott: Yeah.
121:54:29 Irwin: Seems like when we get to the bottom...And I can see the trajectory of the fragments coming from the...It looks like...Yeah, they're coming from the front wheels and coming up kind of around my arm and then forward.
121:54:39 Scott: Yeah, but it's not dusty. I mean, they're...
121:54:41 Irwin: No...No, it looks like millimeter-type particles.
121:54:44 Scott: Yeah. (Pause) Hang on.
121:54:51 Irwin: Okay, let's see, the distance 1.3. Okay, I think there's a large one coming up about 12:30 or 1 o'clock that could be Rhysling.
121:55:04 Scott: Okay.
[At 121:57:14, Jim will report a bearing to the LM of 036, which implies that their average heading has been 216. They are approximately 1050 meters (4.2 grid units) south of the LM and 760 meters (3.0 grid units) west, near BO.1/70.4. The crater could be the circular, 125-m crater at BO.4/70.7, just east of the elongated crater Nameless. They have been on the move since 121:44:35 and, now being 1.3 km from the LM after 10 minutes 16 seconds, their average range rate has been 7.6 km/hr.]121:55:08 Allen: Jim, that sounds good or it could be the large one to the northwest of Rhysling (at about BL.7/71.5). Rhysling may be coming up on your left now.
[Scott - (Chuckling) "You go to any new place, you want to find something that's familiar. Right?"]
[Jones - "Although, in your case, you've got lovely things to guide you on the horizon: St. George and all that."]
[Scott - "But also remember, we've never checked the Rover navigation system, so we don't know it's right. It may say 1.3, but we may be at 1.9 or 0.7 because we'd never done this before and there was a question of wheel slippage. You know, if your wheels slip a lot, your odometer's going to turn a lot, and you're going to think you're a lot further than you are. So we don't really have confidence in the Nav system at this stage of the game."]
[Jones - "So you'd really have liked to have found Rhysling to be sure."]
[Scott - "Find me a place I know, then I know that the Nav system's okay."]
[Jones - "Grant Heiken told me once that if you really blow up the pan camera images (taken from the Command Module in orbit), you can see the Rover tracks."]
[Scott - "Oh, yeah. The tracks are clear on the pan camera. I've seen pictures of that."]
[Jones - "Even though the Rover footprint is smaller than a resolution element, the fact that you're stringing them together makes the track visible. In those same pictures, the LM is pretty marginal, even though it's a lot bigger than the width of the tracks."]
[Scott - "Maybe what you're doing is changing the albedo so that you have a swath instead of two tracks. Throwing all that dust around changes the albedo. So, what you're seeing is not the tracks, but the albedo change due to throwing the dust around."]
[Houston thinks that they landed near November Crater at BR.5/75.3 and, necessarily, would estimate that Dave and Jim are 0.9 grid units south and 2.0 grid units east of their actual location at any point in the traverse. Once they get to a known location - Elbow Crater - the Rover Nav readouts will allow Houston to pin down the LM location and remove this navigational uncertainty.]121:55:20 Irwin: Well, there's a large one over there, too, Joe, I...
121:55:23 Allen: Roger. But your heading is beautiful. Continue on.
121:55:29 Scott: Okay.
121:55:30 Irwin: Our heading's averaging about 200 [to] 210. (Pause)
121:55:44 Scott: (Laughing) Man, this is really a rocking-rolling ride, isn't it?
121:55:48 Irwin: Never been on a ride like this before.
121:55:50 Scott: Boy, oh, boy! I'm glad they've got this great suspension system on this thing. Boy. (Pause)
[Gordon Roxburgh has produced a digital version of the Apollo 16 Grand Prix which shows John Young driving the Rover near the LM. The 16-mm film was shot by Charlie Duke. The vertical LRV motions were higher than they would be with both crewmen on-board.]MP3 Audio Clip ( 17 min 54 sec )
[In 1989, I asked Jim about the ride.]
[Jones - "The suspension didn't damp very quickly, I gather. So it was pretty bouncy, 'pretty sporty', I gather."]
[Irwin - "We had a spring leaf that gave us the support, the suspension. I'm sure Dave would have a lot to say about how it handled and how it felt to ride it. I know there were a couple of times when we'd go up on two wheels - in this time frame - and I thought surely we were just going to roll over. I was concerned that, if we rolled over, would we be able to get out from under it. I'm sure we would, eventually, but it was a concern. With the seatbelt so snug, would we be able to get to it to release it and get out from under the Rover?"]
[Jones - "So were you tipping sideways, occasionally?"]
[Irwin - "Yeah, 'cause sometimes you'd come up and there would be a huge crater ahead of us and Dave would have to throw the control over to a hard right and we'd just go up on two wheels. And I thought, 'Man, we're just going to be rolling over!'"]
[Jones - "Did you go up the other way with Dave on the downside?"]
[Irwin - "I don't ever remember that. (Laughing) I remember I was on the downside. It seems to me, once we went through this indoctrination phase, we always had the throttle full forward. An amazing little vehicle."]
[In 1992, Dave and I had the following conversation about the ride.]
[Jones - "You said earlier in our discussions that the damping was a lot less at one-sixth than one g. You said that, once it started bouncing, it kept bouncing for a while."]
[Scott - "But it also may have been caused by the frequency of impacts of the wheels, because there's so much out there. But, as we've discussed, the pre-mission photos didn't tell you how irregular the surface is. It's never straight. Choppy seas. Real choppy seas. But probably more than choppy seas, because they tend to be somewhat regular. It was a bouncy ride. The Rover, being a rigid body, has to damp out this motion, so the rigid movement over the surface, is a relative smooth curve - it has to be because it's a big Rover with people in it - which means that, since you're on an irregular surface, the four wheels are all doing extra duty. Independently. So it would be interesting to see the oscillation curves of those four wheels, because I'll bet it's a wild thing."]
[Jones - "But I gather that it didn't bottom, very often."]
[Scott - "I think it probably did, but I'd have to go think...We wrote a fairly thorough report on the Rover. I think Jim and I sat down and wrote an airplane-type test report on the Rover. As I recall, it's very detailed 'cause we spent a fair amount of time and we did it just like we'd tested a new airplane. As I recall, we wrote it in terms of performance, stability, and control, because that's what you do with an airplane. First, you find out its performance, how well it goes up and down, climbs, dives; and then how it handles. And I think we wrote this report in this same manner - how it went and how it handled. Which should give you a much better insight than the discussions here."] [Dave is probably referring to the "Pilot's Report on LRV Performance" in Section 9.8.4 in the Apollo 15 Mission Report (15 Mb). That material forms a part of an extensive discussion of LRV Performance in Working On the Moon.]
121:56:08 Scott: Okay, here's a big one right here on our left, Jim.
121:56:09 Irwin: Yes, but I don't think it's big enough to be Rhysling.
121:56:12 Scott: No, I don't think it is either. We got a ridge up here in front of us, we'll...
121:56:16 Irwin: What did I say, Joe, about 1.6, 1.7, for Rhysling?
121:56:24 Allen: It's about 1.4, 1.5, Jim.
121:56:26 Irwin: Get on top of...(Stops to listen to Joe) That could be Rhysling, Dave; we'll find out when we get up on top of this ridge.
[All of the crews had trouble judging sizes and distances. Dave and Jim are having a particularly tough job during this part of the traverse because they had no clear landmarks during the descent to help them figure out exactly where they'd landed and, since leaving the LM, have had no prominent landmarks through this first part of the traverse.]121:56:34 Scott: Yeah. (Pause) By the way, Houston, your comm is crystal clear for us up here.
121:56:46 Allen: So is yours, Dave. Maybe we ought to take this gear to Flagstaff next time.
121:56:53 Scott: Yeah.
[Jones - "This sounds like there were some comm problems with some of the Flagstaff field exercises."]121:56:54 Irwin: Off in the west now, I can see Bennett Ridge.
[Scott - "Yeah. I think over the hill sometimes is a problem."]
121:56:57 Scott: Oh, yeah. I've seen it all the way. You can see just the peak of it almost all the time.
[Bennet Hill is named for descent and ascent trajectory designer Floyd Bennett.]121:57:06 Allen: And Rover, this is Houston. Your range to Rhysling is about 1.7; so you may be short of that still.
[November Crater is at BR.5/75.3, Rhysling is BL.5/72.7, and the distance between those coordinates in 1.63 kilometers.]121:57:14 Scott: It just clicked off 1.7, and our relative bearing's 036.
[These readings would put them 5.5 grid units south of the LM and 4.0 grid units west or about BM.9/69.3 which is between Quadrant Crater, which is at BN.0/70.2, and the edge of the rille. They have been on the move for 12 minutes 39 seconds and have had an average range rate of 8.1 km/hr.]121:57:19 Scott: And we're coming up on the right...
121:57:21 Irwin: Hey, you can see the rille! There's the rille.
121:57:22 Scott: There's the rille.
121:57:23 Irwin: Yeah. We're looking down and across the rille, we can see craters on the far side of the rille.
121:57:32 Allen: Roger. Like advertised.
121:57:33 Irwin: A lot of blocks. (Garbled) to turn the camera on.
121:57:40 Scott: Yeah. (Pause) Now we're getting into the blocky stuff, about 1 foot, quite angular, irregular surface.
121:57:55 Irwin: We're right at the edge of the rille, I bet you.
[Scott, from the 1971 Technical Debrief - "I believe you mentioned that the block distribution - or fragment distribution - did increase somewhat as we got to the rille rim. There were more fragments."]121:57:57 Scott: Yes, sir. We're on the edge of the rille, you'd better believe it. I think we're heading right...
[Irwin, from the 1971 Technical Debrief - "I'm wondering, was that a function of the rille or a function of craters there? I know that was true when we got to Elbow. There were plenty of rock fragments there." (See the discussion following 121:58:43.)]
121:58:01 Irwin: I don't see Elbow though. Oh, yeah, I see Elbow. Dave, we have to stay up on the high part of the rille, here.
121:58:08 Scott: Yeah.
121:58:09 Irwin: See; Elbow is not as prominent as we thought, but there's a definite crater there. I see Elbow.
121:58:15 Scott: Yeah, it's subtle though; subdued.
121:58:17 Irwin: I'd better turn on the (16-mm)camera.
[Scott, from the 1971 Technical debrief - "We did see Elbow Crater from the side of the rille, quite a ways away. And there, again, I think the distances were somewhat deceiving and that it looked closer than it really was. When we did see Elbow Crater, I felt like we were almost there. Then there was a fair amount of driving before we got there. Everything looked closer; and, as I look at our landing site, relative to Pluton, I would have thought Pluton was just right around the corner from the site. I think the distances, again, as everybody has said in the past, they're really deceiving up there with no other objects to measure and compare."]121:58:18 Scott: Hey, look there's a big block on the edge of the rille there that must be 10 meters (across). There are lots of outcrops. But, on the far side, I don't see anything that would suggest really layering. There's a lot of debris, big angular blocks all the way down, but nothing that you'd really call exact layers.
[Using Jim's last reported range and bearing of 1.7/036 and the vlaues they will have at Station 1, 3.2/011, Station 1 is still about 1.8 kilometers away from them on a bearing of 168.]
[The lack of an atmosphere is another important factor. The following is from Charles Darwin, Voyage of the Beagle, p 347, discussing his experiences traveling in the Andes east of Santiago, Chile, in March 1835: "Travelers having observed the difficulty of judging heights and distances amidst lofty mountains, have generally attributed it to the absence of objects of comparison. It appears to me, that it is fully as much owing to the transparency of the air confounding objects at different distances, and likewise partly to the novelty of an unusual degree of fatigue arising from a little exertion,—habit being thus opposed to the evidence of the senses. I am sure that this extreme clearness of the air gives a peculiar character to the landscape, all objects appearing to be brought nearly into one plane, as in a drawing or panorama. The transparency is, I presume, owing to the equable and high state of atmospheric dryness."]
121:58:41 Allen: Roger. We copy.
[They are looking for horizontal layers in the far rille wall which would be produced by successive flows of mare lava. During the EVA-3, they will make two stops near BS/66 on the edge of the rille about 1.7 kilometers northwest of their present position and will take some excellent 500-mm photographs or several areas of distinct layering. Frame AS15-89- 12115 (scan courtesy NASA Johnson) is an example.]121:58:43 Scott: Let me get us back up on the ridge, it's smoother.
[Jones - "Did you stop at all to look around, or did you just keep going?"]
[Scott - "I don't remember. I spent what, about 20 seconds on this description. I don't think we stopped, but I don't remember."]
[At 122:01:50, Jim will report a range from the LM of 2.0 km. As indicated above, their average range rate has been about 8 km/hr but, in the four and a half minutes, they will only average 3.9 km/hr over 0.3 km. This suggests that they stopped to look around or, at least, slowed considerably. At 8 km/hr, they would have covered 300 meters in 2 minutes 15 seconds, suggesting a stop of perhaps of the same length.]
[Jones - "Do you have distinct memories of some of this?"]
[Scott - "Some of it. Depends on what part of it it was. Another challenge is, as we go through it, I start recalling more, but I haven't had time to review it and, if we could go through it twice, or I could sit and take a couple of days to read through the transcripts and think about it, then more would come back. 'Cause, once we get into a discussion, I start remembering things. But, I have to get into that discussion and get into that memory bank. If we had done this a year afterwards, it would be easy. But it does come back as we go through it. I do start remembering."]
[Checklist pages LMP-9/CDR-9 have a list of features of interest to the geologists. Fillets are skirts of dirt that build up at the base of rocks from dirt that is thrown against them by impacts. On Apollo 12, Pete Conrad and Al Bean investigated two conical mounds of soil that they found near Head Crater, the only such structures found by any of the crews. As for the "possible ray", it was generally assumed from morphological evidence that the craters of the South Cluster were formed by the impact of ejecta from one or both of two very large craters - Aristillus and Autolycus - hundreds of kilometers north of Hadley and, in the pre-mission photography, there was a suggestion of an associated ray, presumably created by finer-grained ejecta from the same large craters.]
[Irwin, from the 1971 Technical Debrief - "We were supposed to be looking for a possible ray, and I saw no evidence on that leg (of the traverse) of any ray."]
[Irwin, from the 1971 Technical Debrief - "You know, when we first saw Elbow, I think we were kind of downslope, down on the rille side of the levee. We saw it, and we went back up on top of the slope. It was smoother driving up there."]121:58:47 Irwin: Yeah, I think that heading was...We were on a heading that was a little too far west. We're getting back up on the higher part of the rille rim. At this point, I'd estimate the slope is probably - what? - About 3 degrees?
[Scott, from the 1971 Technical Debrief - "You're right. Matter of fact, I think we commented at the time it was better driving back up on the ridge line, or the raised point if you don't want to call it a levee - which, I guess, I agree wasn't really a very profound levee, if it was at all."]
[The current scientific thinking about Hadley Rille is that it is a lava tube or channel, a relic of the mare forming period of lunar evolution. The point on the edge of the rille where the slopes become steep more or less marks the original edge of the tube. Over the billions of years since the end of mare formation, the mare surface - and the rille walls - have been hit by countless impactors, most of them quite small. Away from the rille, these impacts have produced the regolith layer which is now more than 5 meters thick. Near the rille, some of the larger impacts spray ejecta far enough that the rille-ward portion of the ejecta blanket goes into the rille, and the net result is that, as illustrated in Figure 5-30 from the Apollo 15 Preliminary Science Report, the closer one gets, the thinner the regolith and the more exposed boulders and bedrock outcrops one finds. Dave and Jim will make a close examination of the edge of the rille at Station 9 during EVA-3. Photo AS15-82- 11147 is an excellent view of the rille edge at that location. In that picture, Elbow Crater is the relatively light-colored feature just to the right and below the fiducial mark two above the central fiducial. A portion of St. George Crater can be seen at the upper-right corner.]
121:59:03 Scott: Yeah, there's a definite ridge or rim that runs along the rille, maybe 70 (or) 80 meters from the inflection point that drops down into the rille, don't you think, Jim?
121:59:15 Irwin: Yeah. (Pause) And, we might as well...We're heading right toward...We'll head toward the east side of Elbow.
121:59:24 Scott: Yeah, we're in good shape. We can see Elbow, and we can see the Front all the way down to the Spur (that is, Spur Crater). And, there's not a big block on it. (Pause)
[Dave and I tried to decide if this is a reference to Spur Crater, to Silver Spur, or to some other feature.]121:59:37 Allen: Keep talking, keep talking. Beautiful description.
[Scott - "Yeah, it is Spur Crater. We're looking at the trafficability. Remember? We're worried about being able to drive along the Front. That's why we did the SEVA. So, what I'm looking at is down (that is, eastward along) the Front, so it is Spur Crater."]
121:59:40 Scott: (To Jim) Hang on.
121:59:42 Irwin: I see one large block, about a quarter of the way up the Front, Dave.
[This could be the green-tinted boulder they will sample during the Station 6a stop on EVA-2.]121:59:48 Scott: Okay, hang on there.
121:59:49 Irwin: Yeah.
121:59:51 Scott: (Chuckling) There's a big one (a rock close at hand) partially buried. Oh, there's some beautiful geology out here. Spectacular! (Pause) Oop, watch out. Hold on. (Pause)
[Irwin, from the 1971 Technical Debrief, commenting on the block distribution as per LMP/CDR-9 - "I didn't see any pattern (in the block distribution, such as might be associated with a ray), other than the distribution related to individual craters. I didn't see any difference as we drove down there (to Elbow Crater)."]122:00:10 Irwin: Looking up at the front now, Joe, I sure see the linear patterns that Dave commented on before. With the dip and everything.
[Scott, from the 1971 Technical Debrief - "Occasionally we'd see a block - not a block, but a large fragment. I wouldn't even call it a block (but) a "foot" kind of fragment (that is, a piece of rock about a foot across), like the one we ran over. That was an occasional kind of thing."]
[Irwin, from the 1971 Technical Debrief - "Again, that was associated with a particular crater, I think."]
[Scott, from the 1971 Technical Debrief - "Yes, Probably was. We didn't see the excavation of bedrock by 25-meter (diameter) craters. We did see some fresh craters (of) that size, but the general surface was very hummocky and had a relatively heavy crater density, but all subdued and rounded with low rims. No raised rims. But they were larger than 25-meters craters, which did not excavate bedrock and showed no signs of outcrop of bedrock."]
[A fresh 25-meter crater will be about 5 meters deep and the absence of blocks excavated from bedrock indicates that the typical regolith depth at Hadley is greater than 5 meters.]
[Scott, from the 1971 Technical Debrief - "On the lineament thing, I think you can see lineaments if you look for them. That's true as a function of Sun angle and the angle at which you're looking, because you can imagine them in almost any direction. I could almost say there are lineaments anywhere, if I really used my imagination, although some places they appeared more evident than others. I saw one place where it looked to me as if they were running along the (so-called) lunar grid, northeast-southwest, northwest-southeast."]122:00:18 Scott: Whew, whoopee!
[Readers may wish to consult the discussion of lineaments in the Apollo 15 Preliminary Science Report. Although the prominent layering in Silver Spur shown in AS15-84- 11250 may represent real structure in the mountain and, as well, a subtle set of nearly horizontal features on Mt. Hadley seem to comprise benches that may have formed as a result of slumping on the steep mountain face, there is a strong possibility that most of the linear patterns seen at Hadley and other sites are the result of lighting effects. Frame AS15-84- 11321 shows a prominent set of lineaments running diagonally down from the upper right to the lower left on Mt. Hadley as seen during EVA-2 from Station 6 on the flank of Mt. Hadley Delta. The Sun is at the right.]
[They've hit a small crater which must have been hidden beyond a small rise. They are driving SSE, so there should be plenty of visible terrain definition when they are driving on level ground or going down slopes.]122:00:19 Irwin: Boy, that was a good stroke.
122:00:21 Scott: It's a good stroke, all right.
122:00:24 Irwin: And, I sure get the impression it's a...Almost looks like a slump feature, but we'll take some good pictures of that. (Pause) You see the same linear-type pattern in the east side of the rille. And note the linear pattern there is parallel. Almost like layering in the rille. And, then as you look upslope - up the Front - that layering takes that dip to the northeast that Dave had mentioned earlier.
122:01:02 Allen: Roger, Jim. And can you actually see the east side of the rille, towards the south there?
122:01:09 Irwin: Oh, yeah. I can see...Looking directly south I can see the exposure that faces northwest. I can look down and I think I can see Hadley C down there!
122:01:23 Allen: Remarkable.
[Hadley C is a large, prominent crater about 30 kilometers southwest of the LM and about 28 km from Station 1. As indicated in a detail 0.5 Mb ) from the Hadley Lunar Topographic Orthophotomap ( 12.2 Mb ), the highest part of the Hadley C rim is on the northwest and, as seen from Station 1 would be about 24.5 degrees in azimuth from the summitt of Bennett Hill. A labeled version of AS15-85-11415 ( 192k ) shows two peaks to the south of Bennett Hill - one about 17 degree from the high point on Bennett Hill and the other about 21 degrees; and these approximate azimuth differences are consistent with two peaks on an unnammed hill about 44 km from Station 1, as indicated in the detail from the topographic map. In addition to the azimuths, we note that the apparent heights of the two peaks are consistent with the distances from Station 1. The contours on the topographic map indicate that the summit of Bennett Hill is about 1 km above Station 1 and, taking into account the curvature of the Moon, at a distance of 24 km, the summit would be about 2.0 degrees above the horizon. The leftmost of the two peaks on the unnamed hill is about 1.4 km above Station 1 and, at 44 km distance, would stand about 1.1 degrees above the horizon. In contrast, the highest point on the rim of Hadley C is on the northwest and is only about 0.3 kilometers above Station 1 and, at 28 km distance, would stand only 0.14 degrees above the horizon. Making allowances for the fact that his camera was tilted when Jim took 11415 and for the rim of St. George blocking part of the distant horizon on the right, we can conclude that the two peaks seen in 11415 are quite clearly the two peaks on the unnamed hill and that, at Station 1, the rim of Hadley C is blocked from view by the rim of St. George. Nonetheless, when Jim reported seeing Hadley C, it is possible that they were far enough north that the rim of St. George would not have been a factor.]122:01:24 Irwin: Yeah, I think I can see the south rim of Hadley C. (Pause) Okay, let's see. Well, we can see Elbow. But anyway, when we get there...
[Note that the large model of the landing site used to provide window views for the LM simulator during landing and ascent does not include Hadley C. Consequently, Joe's 'remarkable' can not refer to the simulated Rover traverses that he watched Dave and Jim do in the final days before launch. On the other hand, the prospects for seeing Hadley C from the surface may have been something they all discussed before the flight.]
122:01:43 Scott: Hang on; got one coming.
122:01:45 Irwin: Okay.
122:01:47 Scott: (Subvocal) Oh, my.
122:01:50 Irwin: It should be 2.7 (kilometers to Elbow Crater). So we got another .7 to go.
122:01:55 Scott: Okay, we're doing all right.
122:02:00 Irwin: Speed's been generally about 10 clicks (kilometers per hour).
122:02:02 Scott: Yeah, but it takes attention paying. (Pause)
122:02:11 Irwin: Yeah. And again, looking to the south along the edge of the rille that faces to the northwest, I can see several large blocks that have rolled downslope. Very large blocks that are about three-quarters of the way down the slope, into the rille. That's just at the base of St. George.
122:02:32 Allen: Roger, Jim. Copy. (Pause)
[Jones - "On 16 and 17, Charlie and Jack took pictures with the Hasselblads during the traverses, almost religiously, every 50 meters or so. Do you remember any discussions about that?"]122:02:40 Irwin: And...Let's see, we're heading about 165 right now. Tried to stay on the fairly level and smooth part of the Rille rim. But looking over to the edge of the rille at this point, I see a large concentration of large boulders - large rocks. And I'd estimate the size...They're angular, and they're all of the same color and texture as far as I can tell from here. (To Dave) See that con(centration)? Well, you'd better watch the road, Dave.
[Scott - "I don't think we did that. I know I took a couple."]
[Jones - "Of particular things as they came along."]
[Scott - "I'm not sure we had any film programmed for that. It would be a good idea, though."]
[Jones - "Yeah. It worked great."]
[One possible explanation for the change in procedures is that, for 15, there may have been an assumption that the traverse would be well covered by the 16-mm movies. The failure of the 16-mm camera may have gotten people thinking about still photography as an alternative.]
122:03:22 Scott: Yeah. No, I see what you're saying there, but you keep talking; let me drive.
122:03:28 Irwin: Yeah. It's the first good concentration of large rocks that I've seen. Very similar (in size and angularity) to the large rocks that 14 saw up at the top of Cone.
122:03:42 Allen: Roger, Jim, we copy. And your range should be coming up on 3.1, at Station 1.
122:03:51 Scott: Okay, right now, Joe, our bearing is 18 and range is 2.3.
122:03:57 Allen: Roger. (Pause)
[These readouts put them near BJ.7/70.5 on the map, a point down on the eastern rille wall. Because they are actually driving parallel to the rille but safely east of the drop-off, there is an error in our estimate of their current location of about 0.5 grid units or about 125 meters. This is typical of the errors seen on Apollos 16 and 17 in Nav readouts at well-determined locations. See the table and related discussion in the Apollo 17 Lunar Surface Journal at 164:48:12.]122:04:08 Irwin: Okay; now, Joe, I can see the bottom of the valley - Head Valley - that leads down toward Hadley C.
[Jones - "Head Valley is for Jim Head and it's nicely disguised so the International Astronomical Union (IAU) would never tumble to it."]122:04:18 Irwin: I can see the bottom of the rille. It's very smooth. I see two very large boulders that are right on the surface, there (that is, they are unburied) - on the top of the very smooth portion, of the bottom of the rille. And the one to southeast, I can see the track (on the rille wall) of where it's rolled downslope.
[Scott - "It wasn't intentional. All of the IAU exercise occurred after the mission. And they complained about everything. We had Head Valley, Silver Spur, the Swann Range, Schaber something. Bennett Hill. I told you that story, didn't I? If we overshot the rille, we would land on the west side and we called the mountain over there Bennett Hill, after the guy who designed the landing trajectory for us, Floyd Bennett. Our landing trajectory was twice as steep as the others, so we spent a lot of time with him, and he with us. He put so much effort into this - making sure that we didn't end up on the far side of the rille or that we didn't run into the mountains - we decided to name this prominent feature Bennett Peak. So there are a lot of scattered names around there."]
[The chairman of a nomenclature committee of the IAU, Harvard astronomer Donald Menzel, had a running battle with NASA over names for lunar features and frequently demanded that NASA submit lists of proposed names prior to the flights. Those requests were largely ignored.]
[Scott - "Although we were probably aware of this, we really did not give it any consideration in selecting names. Did you know that Hal Mazursky did a long letter to the International Astronomical Union to get the names on Apollo 15 approved? And got turned down."]
[Jones - "I've heard a similar story on 17. Tell me the 15 tale."]
[Scott - "Mazursky was a member of the IAU, and he prepared a letter which he submitted formally, to get official recognition of all the names. And the head of the IAU wrote a response, which is marvelous! Because he turned down every name for a reason, and he wrote a paragraph or so on every name and why it was unacceptable. It's amusing, it's interesting, it's educational. And Mazursky's, as I recall, was excellent. He wrote down all the names and the rationales for each name. And then the one he got back was like...I mean we had one crater called Nameless Crater (at BO.5/69.9), and the guy wrote back, 'You can't have a Nameless Crater, 'cause that's no name. And if I were naming it, you should name it this. You should have a name.'"]
[Scott - "Hal passed away a number of years ago. Great guy. There's another one of those marvelous professors. Inspirational professors. I could listen to Hal Mazursky all day and all night. And he'd come to the Cape and he'd come to the crew quarters and he'd tell us about the Moon. Spellbinding. Absolutely spellbinding. Marvelous guy."]
[Jones - "One of my purposes in preparing the Journal is to make sure that the names that you folks decided were appropriate get thoroughly recorded and used. My personal feeling is that it's always the privilege of the explorers and/or pioneers to do the naming. As long as astronomers were exploring the Moon with telescopes, then it was appropriate for them to do that. But as soon as somebody landed, the responsibility shifted to the people who landed and the IAU could go to hell."]
[Scott - "I've never heard that approach. That's a good approach."]
[Jones - "And once there are folks living in the area, they can name things that you didn't name. Dot Crater at Apollo 16 is named for Charlie's wife and everybody should know that. And Punk for Gene's daughter, Tracy. So as we come along to names and you remember why certain names were chosen, let's talk about it."]
[Scott - "And there was a reason for having names rather than numbers. Because I can remember a name with a character, how that character looks with the name. I get lost in numbers. If this is Crater 46 or 48 or 72, it doesn't mean anything to me. I need to know the name, and then the crater will take on a character, like a person. So you get to Dune Crater (at BG/77). That is Dune. Boy, you look at it and it's Dune. You know, we did a lot of ours on Science Fiction, because that was fun. It brings it to life, because there's some relationship. The names are very helpful when you're trying to make your way around the Moon."]
[Jones - "Were you a science fiction reader? As a kid?"]
[Scott - "I frankly don't remember when I did it, and I probably wasn't that deep. But I did like it, and I did find that it was fun to bring all of these things out when we were doing geology and, as a by-product, naming craters. And why name craters? And the science fiction was a good reason why, because there were a lot of relationships that you could mentally tie in. And you're probably a science fiction reader."]
[Jones - "Yes. So Rhysling, the Blind Poet in Heinlein's 'Green Hills of Earth', and Earthlight and Dune and all those were immediately obvious to me."]
[Scott - "Heinlein is one of my favorites; 'The Green Hills of Earth', boy, that's a great story. And (Arthur C. Clarke's) 'Earthlight'. That's still a great story. In fact, I still give copies to people once in a while, because that's the first lunar base. And that's at Hadley. And that's a great story, not only because it's entertaining, but because it could be a very valid forecast. Of course, Arthur Clarke does great work. And there's a real message in that story, which people should pay attention to, especially today with the things that are going on. When I talk to people in Washington about the lunar base, I tell them 'You're going to have to take care of it, protect it.' It's going to happen. You're going to have a lunar base. And all those things you don't pay any attention to now, if you pay attention to them now they'll help you out when you get to your lunar base."]
[Dduring this discussion, I neglected to get confirmation from Dave that Dune Crater was named for Frank Herbert's 1965 novel 'Dune'. In a 2014 exchange of e-mail with Dave, he said, "Indeed it was".]
[Jones - "The crater naming was a cooperative venture between you and Jim and Joe..."]
[Scott - "We did most of it at the Cape during our post-dinner geology sessions. Jack Schmitt was a major participant in one of them. Do you know why St. George Crater has it's name? 'Cause one night we were discussing what we would find at that crater - anorthosite or whatever. And Jack got in a heated discussion with somebody. (See below) I forget who it was, Lee Silver or (Gordon) Swann or somebody. But, you know, when Jack takes a position, he takes a pretty hard position. And they got down to 'I'll bet you'. 'What do you want to bet?' 'I'll bet you a bottle of wine.' 'Okay, I'll bet you a bottle of wine, what kind of wine?' And somebody says, 'You know, one of Jules Verne's characters (Michel Ardan) took a particular bottle of wine called Nuits-Saint-Georges to the Moon. Therefore, why don't we name the crater St. George Crater, after Jules Verne. And that's why it's St. George."]
[See Chapter 3 of Verne's Around the Moon.]
[Scott - "That's what brought geology to life. That's the kind of thing that made it fun, it made it real, and it tied it in with other things. It got into the emotion of the time, which was good because it was great to hear somebody like Schmitt debate with somebody else what was going to be there, because the rest of us learned a lot from that. You listen to a debate, you learn a lot, right? So those kinds of things were a very meaningful part of the methodology. How did we learn how to be quasi-geologists on the Moon? Because of things like that. How could I ever forget that Schmitt had this argument about anorthosite at St. George? I can't forget that. So I get up around St. George, and there is a (mental) hook and, hanging on that hook, is a bottle of wine. And, as a total sidelight, after the mission was over, I got a package from George Low. In the package was a cork, from a bottle of Nuits-Saint-Georges that he had on the night we landed on the Moon, and he'd signed it. Not bad, huh?"]
[Jones - "The publishers we've approached are all afraid of the size of this thing. Not a one of them doubts the proposition that, 300 years down the line, there are going to be some treasured copies at the community library at Hadley or where ever it is. And, there, people can read what you just said, and look out the window, at St. George, and know about Jack's argument and your mental hook. That's the kind of stuff that has to be in here."]
[Scott - "Absolutely. That's what makes it human. We can send robots, but that doesn't make it human. It doesn't give you the vigor."]
[Although I still do not know with whom Jack bet with regard to anorthosite at St. George, Grant Heiken, editor with David Vaniman and Bevan French of the marvelous Lunar Sourcebook has provided a copy of an original, signed document that formalized a series of bets Schmitt made with Robin Brett concerning Apollo 17.]
[On a final note, Journal Contributor Harald Kucharek notes that the village of Nuits-Saint-Georges is justifiably proud of its double connection with the Moon. In a 2001 e-mail message Dave Scott says that he and Jim and Al Worden made a visit in conjuction with their attendance at the 1971 Paris Air Show. Dave writes that Nuits-Saint-Georges is "a marvelous little town, with marvelous wine, marvelous food, and marvelous people!!!" He says that they were able to "enjoy the 'fruits' of our labor...(and were)...honored by being made citizens of Nuits. Just wish we could go back for another round!!!"]
122:04:53 Allen: Roger, Jim. Copy. And is the bottom V-shaped or fairly flat?
122:04:59 Irwin: I'd say it's flat. Well, it's hard to estimate. I'd estimate maybe, oh, 200 meters wide of a flat area in the bottom.
[Irwin - "(In 1971) most of the scientists were saying the rille's probably a collapsed lava tunnel. I don't know if that's still the theory or not."]122:04:12 Irwin: Oh, and I can see what we thought was Bridge Crater. And it definitely would not have been a place to cross Hadley Rille. It's just a depression in the west wall of the rille.
[Jones - "I think that's still the favorite one. There's some discussion that it might have been a fault zone; but, then, if you've got weak zone, it's also a place where you could have a channel for the lava to flow."]
[Orbital photos such as AS15-87-11720 give the impression that it would be possible to cross the rille via the western rim of Bridge Crater.]122:05:30 Irwin: And I...Boy, at this vantage point, there's sure a lot more blocks exposed on the...
[Jones - "If you had landed long, on the other side, would you have stayed on the other side?"]
[Scott - "I don't recall. Maybe that was the bridge to get back to St. George."]
[In 1989, Jim was also unsure if they had ever talked about the possibility of driving across the rille from a landing site on the west side. This suggests that it was never more than a point of casual discussion, if that.]
[Scott, from a 1996 draft review - "We did discuss this possibility and that is the reason for the name. But, remember, the photos only had about 20 meter resolution - not really very good for serious planning."]
122:05:38 Scott: (Laughing) Yeah!
122:05:39 Irwin: ...on the far side of the rille. I'm contrasting now the rille to the southeast...
122:05:47 Scott: Oop, hang on, Jim.
122:05:48 Irwin: Okay. (Picking up his comment again)...and the side of the rille to the northwest.
122:05:52 Allen: Roger, Jim. Copy all that, loud and clear. And Dave, are the front wheels wandering off of straight ahead as you drive along there?
122:06:04 Scott: No, they're okay, Joe. It's just (that) there are a lot of craters and it's just sporty driving; I've just got to keep my eye on the road every second.
122:06:12 Allen: Roger. We understand that...
122:06:13 Irwin: By golly, it's a real test for the Rover.
122:06:14 Allen: ...just want to get some engineering information here. Apparently, your front wheels are tracking straight ahead, is that correct?
122:06:23 Scott: That's correct. And, of course, when we turn, they dig in, and it makes the rear end break out (that is, start to swing around). But it's okay; we can handle it.
122:06:31 Allen: Knew you could.
122:06:33 Scott: I might add to Jim's comment, that the near side of the rille wall is smooth without any outcrops, there by St. George, and the far side has got all sorts of debris. It almost looks like we could drive down in on this side, doesn't it?
122:06:48 Allen: Stand by on that, Dave.
122:06:49 Irwin: I'm sure we could drive down; I don't think we could drive back out. (They both laugh about Joe's warning.)
[Scott, from a 1996 draft review - "This was a typical Joe Allen quick response - in a humorous vein - since we had discussed driving down into the rille many times before the flight, but not really seriously."]122:07:00 Irwin: Oh, now I can turn around and look to the northwest - where the rille trends to the north. But I'll...let me concentrate on Elbow for the moment.
[The wall beneath St. George is probably covered with St. George ejecta and/or other fine material which has tumbled down off of Hadley Delta, piece by piece. Beyond the west wall there is only the relatively flat mare and, apparently, there has been insufficient erosion to completely bury outcrops in the steeper parts of the western rille wall.]
122:07:11 Scott: Yeah, let's get to Elbow. (Pause) (Jim laughs) Hang on.
[Jones - "I had the impression you could turn your head in the helmet a fair bit..."]122:07:26 Irwin: Okay, the range estimate must have been off for Elbow. Our map says 2.7 (kilometer range from the planned landing site to the east rim of Elbow); Joe said 3.2, I guess. You confirm that, Joe?
[Scott - "We did have the side panels. But he says he could turn around. He could probably turn around in the seat. Depends on the angle you're looking at and the angle you're driving."]
[Jones - "Sitting here in my chair without moving anything but my head, I can get around to 90 degrees and, with peripheral vision, get around quite a ways back."]
[Scott - "But he might have meant he could turn the suit."]
[Jones - "Even with the belt on?"]
[Scott - "Yeah. I think you could probably turn the suit a reasonable amount - if you're not driving. I mean, the belt keeps you here..."]
[Jones- "You could really rotate the torso?"]
[Scott - "I don't know that I ever really tried. This is the first time I've ever discussed it. There was no joint, at that time (for that motion), but you could make it bend, twist if you will."]
[Jones - "Especially if you could grab something outboard with one hand and pull yourself around a little."]
[I asked Jim about this statement, too.]
[Jones - "Jack gives me the impression that it's almost impossible to move the suit, itself and, consequently, to move the helmet. You can move your head inside the helmet, but then you're blocked from looking past about 90 degrees."]
[Irwin - "Well, I must have been able to look off to the right, there, to look northwestward."]
[Jones - "Would you agree with Jack's statement that you would not have been able to twist the suit?"]
[Irwin - "I don't think you actually twist the suit. (pause)"]
[Jones - "So it was a matter of the Rover being turned enough so that that direction came into your field-of-view."]
[Irwin - "Yeah. I'm not implying I was able to move my upper body that far, but I guess I could move it slightly and look in that direction."]
[Another possibility is that, by leaning his head forward and then turning it, he might have been able to look a bit more toward the rear.]
[Scott, from a 1996 draft review - "You might have been able to 'bend' the suit - not 'twist' - from the shoulder to the waist if you could hold onto something. Perhaps video of the work at the ALSEP would show something."]
[In a quick scan through some likely spots in the Apollo video, I was able to find one instance at Apollo 17's Station 8, at about 167:04:22, where Jack Schmitt appears to rotate his shoulders relative to his hips, but certainly not by more than 10 or twenty degrees.]
122:07:36 Allen: Our estimate, Jim, was 3.1 from your landing site (that is, from the presumed landing site near November Crater).
122:07:43 Irwin: I see, that's right.
122:07:44 Scott: That's the difference.
122:07:45 Irwin: Yeah.
[Because they landed 600 meters north of the planned spot, they won't get to Elbow at a LM range of 2.7 kilometers but, rather at a true range of 3.3.]122:07:51 Scott: (Laughter) Well, this is really a sporty driving course. Man, oh, man, what a Grand Prix this is! (Pause) There's old Elbow. Isn't it? It's the real fresh one down here.
122:08:10 Irwin: No, Elbow's larger than that.
122:08:12 Scott: Yeah, but there's...Yeah, there's a nice fresh one there.
122:08:14 Irwin: Yeah, but you want to go a little farther east. See, that's Elbow out at 11:30.
122:08:19 Scott: Oh, yeah. Rog. Gosh, that's a long way away.
122:08:22 Irwin: Yeah.
122:08:23 Scott: Distances are very deceiving! (It feels) like we've been driving for an hour. (Pause) Are you sure that's Elbow, Jim?
122:08:34 Irwin: Yeah. Yeah, you want to go farther east, Dave.
122:08:38 Scott: Okay. Down this little crater; back up. (Pause)
[Jones - "I take it you decided that you could drive down into the shallow ones?"]122:08:51 Irwin: See, that's Elbow out at our 1 o'clock position.
[Scott - "Yeah, the vehicle's very mobile. It's just that with all the blocks all around, you had to watch it, every second."]
[Jones - "And make a judgment if they were shallow enough to go down in them or whether you wanted to detour?"]
[Scott - "I don't think there was much detour. I think the detour was around the blocks and the debris. I think we could motor right on through the craters. The fresh ones with all the debris we might have gone around, but the shallow ones, the Rover just moved right along, briskly. It would be interesting to get pictures of the tracks, to see how we traversed going down there."]
122:08:53 Scott: Shoot, this is Elbow right here, I believe, my friend.
122:08:56 Irwin: Yeah, this is Elbow right here.
122:08:57 Scott: Yeah.
122:08:58 Irwin: Yeah, this large one.
122:08:59 Scott: The one we were just trending into.
122:09:00 Irwin: Yeah.
122:09:01 Scott: Yeah, that's some big fellow, isn't it?
122:09:03 Irwin: Yeah, it sure is. I don't know...
122:09:08 Scott: Take a look up here (for a parking spot), and we'll see how she looks.
122:09:10 Irwin: Maybe you can, you know, angle up hill here?
122:09:12 Scott: Yeah. (Pause) How are we doing on time there, Houston?
122:09:18 Allen: Like gangbusters, Dave and Jim. Continue on, and we'll give you the exact number in a minute.
[As per checklist pages LMP-9 and CDR-9, they had planned on a 26 minute traverse, starting at an EVA elapsed time of 1:25 and ending at 1:51. The EVA started at 119:39:08, the traverse started at 121:44:35 or an EVA elapsed time of 2:05. They are currently 25 minutes into the drive and at an EVA elapsed time of 2:30.]122:09:27 Scott: Okay. Do we want to stop at Elbow, or press on?
[Jones - "You're at Elbow Crater and it's been 2 1/2 hours since you opened the hatch."]
[Scott - "A lot of overhead."]
[Jones - "But it's overhead that should be spread over three EVAs."]
122:09:32 Allen: Stop! Follow the Checklist, just as planned.
122:09:37 Scott: Just as planned, okay. (Pause) Okay, let's go right up on the ridge line there, I see some debris. Maybe we can get a fresh one in the rim (that is, find a small, fresh crater which has punched into the Elbow ejecta). Be looking down-Sun (into Elbow with the TV). (Pause) Oh, look at this baby climb the hill.
122:09:53 Irwin: Yeah, climbing at about 8 clicks
122:09:55 Scott: Yeah, man. (Pause)
122:10:00 Allen: Jim, can you get an Amp reading for us as you climb?
122:10:01 Irwin: Okay, Elbow's out there...(Answering Joe) Yeah, reading...Oh, it's just about. It's 10 on Batt 1, Joe.
122:10:15 Allen: Roger.
[Jones - "What they're doing, I presume, is trying to get a reading on Rover performance on this relatively modest slope in anticipation of the climb up to Station 2."]122:10:21 Irwin: We got a good slope here about, I'd say 10 degrees; we're going up right now (to the Elbow rim).
[Scott - "I don't think they know we're going to climb to Station 2. See, they don't know the elevation (difference), really, because the photography was never that good. I think, when we got up the side of the mountain, we were all surprised at how far up we were. I don't believe anybody knew. I mean, we were going up to the front but, with the photography we had, there was not a good relief map anywhere."]
[The EVA-1 contour map in the Apollo 15 Lunar Surface Procedures volume indicates only a modest climb of 10 meters from Elbow to the planned Station 2 location. Dave and Jim will actually make their Station 2 stop quite close to the planned location but will have a much steeper climb than anticipated.]
[Jones - "Was the lack of a good relief map due to the fact that the Lunar Orbiter high-resolution stuff was almost all in the equatorial band?"]
[Scott - "No. Hadley C had good, high resolution stuff, but we had the 20-meter stuff. As we've discussed previously, one reason we didn't know where we were was (the fact that) the maps weren't good enough. They didn't have anything to work with; 20-meter resolution isn't very good. You can't identify many craters that way. So I doubt that there was much good understanding of the relief."]
["I think it surprised everybody that the Rover could perform that well going up the hill (to St. George). That's why, we say we're going up and somebody in the backroom says, 'Boy, we better check and see if it's dragging the battery down.' Because ten degrees is steep. But, in fact, the slope's probably not dragging the battery down and the Rover's doing a great job. The wheels have great traction."]
["We ended up going up slopes that we don't realize were there. And I remember that clearly. Especially later on (during EVA-2). All of sudden, you get off on this...It feels like a cliff - which it isn't - it just feels that way. And we had no idea we were going up. 'Cause there's not much force. You're not leaning back or anything in one-sixth...You don't notice the lean. And you're focused on the direction and there's not a real horizon around. There are no vertical trees. As far as it feels, you're on a flat surface, going level, when, in fact, you're going up pretty steep. If you go down into a crater, you can see you go down and up. You can feel it. (But not on a steady slope.)"]
[In the 1971 Technical Debrief, Jim mentions that east rim of Elbow was "very subdued". Dave added that "there wasn't a raised rim at all". Dave and Jim have been driving along the "ridge" that runs parallel to the rille but were probably still below the level of the general mare surface and, here, are climbing the ejecta-covered slope on the northeast side of the crater up to the mare surface on the east side of the crater.]
122:10:27 Scott: (Garbled, probably as they hit a small crater)
122:10:29 Irwin: I felt it.
122:10:32 Scott: Did you feel that?
122:10:33 Irwin: Okay, now we're up on the high part, and we're on the east rim - east rim of Elbow.
122:10:41 Allen: Stupendous.
122:10:46 Scott: Okay, this ought to give the folks back home something to look at. Right here. Okay, we're at our first stop. Okay. Power this beauty down. (Pause)
122:11:06 Irwin: And, Joe, here's some readings for you.
122:11:08 Allen: Roger.
122:11:11 Irwin: (Rover heading) 185, (bearing to the LM) 011, (distance traveled) 04.5 (km), (range from the LM) 03.2, (amp-hours remaining) 105, 112, (battery temperatures) 085, 087, and...Gee, I'm reading the lower limit on the Motor Temps, both Forward and Rear. Don't look like that gauge is operating.
122:11:45 Allen: Maybe they're still cool.
122:11:51 Scott: Let's hope so. Okay, Joe, I'll give you FM/TV here.
122:11:58 Allen: Roger. (Long Pause with static)
[At 129:06:38, Dave tells Houston that he parked the Rover near BE.5/70.9, a spot virtually on the eastern rim of Elbow. The LM bearing and range of 11 degrees and 3.2 kilometers would put the LM at BS.1/73.3, a spot only 75 meters from the BS.4/73.3 location that Dave estimates at 129:05:07.]Video Clip 0 min 44 sec ( 0.2 Mb RealVideo or 7 Mb MPG )
122:12:27 Scott: (Static fades) Okay, Joe. High gain's pointed. And we've got a fair amount of dust on the Rover. Very light, thin (cover of dust). (Long Pause)
[TV on. At the moment the camera is pointed down and aft, showing us the leftside battery cover. Details are relatively indistinct because of dust on the camera lens.]122:12:52 Allen: And, Dave and Jim. We gained 20 minutes back. We're making money hand over fist on your driving.
[As indicated by the calculation following 122:09:12, Joe is mistaken. The drive took the expected 26 minutes. Joe acknowledges his mistake at 122:28:47. Readers should note that, because they landed farther north than planned, the average speed of the traverse, 3.2 kilometers in 26 minutes (7.4 km/hr) was higher than the expected speed of 2.7 kilometers in 26 minutes (6.2 km/hr) by 20 percent.]122:13:02 Scott: Okay, I see the (TV) camera coming up. (Pause)
[Jones - "In some ways, 15 was the last of the development flights. Because you added the last major element to Apollo - the Rover."]
[Scott - "The suits, too. There were two steps. The first step was doubling the amount of time you could spend outside in the suit. Big step. And the second step was putting the Rover on. And I would weigh them about the same, in terms of importance."]
[Jones - "Now, the original PLSS had about a 6-hour capacity. That's a 4-hour EVA with plenty of margin. Whereas, you guys had about a nine-hour capacity in the PLSS - a 50-percent increase - with the same two-hour margins."]
[Scott - "And there's really more than a 50 percent increase, because you'll have a fixed amount of overhead getting started, with either configuration. Which means that you have a much bigger increase in productive time. So, if you had a six-hour PLSS with three hours of productive time, and you went to a nine-hour PLSS you'd have six hours of productive time, because the overhead would be no more. So the benefit of extending it was all productive time. And that was a major step, in my opinion, because it multiples the Rover performance. Without the step in the suit, you wouldn't have the benefit in the Rover that you had. So, if you try to say which was more important, I think I'd have them both about the same. It's a qualitative judgment."]
[As Fendell raises the camera, we see Dave working at his seat. He is wearing a pair of tongs attached to his yo-yo which, in turn, is hooked to his hoses at his left hip. We can also see the pack of individual sample bags hanging from the bottom of his camera. Note that Dave has red stripes on his knees, elbows, and on his helmet while Jim has no stripes.]122:13:12 Scott: Never got that Velcro on the gnomon bag fixed.
[Irwin, from the 1971 Technical Debrief - "(During the Rover setup at the LM) I fastened the gnomon bag to the back of Dave's seat, and I guess we had a problem with the bottom of it coming loose."]
[Scott, from the 1971 Technical Debrief - "First time I pulled it out (here at Elbow Crater)."]
[In a detail, which Jim will take at Station 2, we can see that the bottom of the gnomon bag is clearly not attached to the back of Dave's seat and we can see what appears to be a Velcro loop or strap intended for that purpose. A detail from a frame in Jim's EVA-2 Station 6 pan, AS15-85-11491 shows the stowed gnomon, with the bottom of the bag apparently attached to the seat. See, also, training photo 71-HC-722.]
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