MP3 Audio Clip ( 11 min 47 sec )
143:31:21 Duke: Okay. DAC's coming on. (Grunting as he reaches forward) Mark.
[Jones - "How hard was it to reach forward to get the DAC?"]143:31:29 Young: Okay, give me that first heading again, Charlie.
[Duke - "It wasn't so far. It was just up here - left arm up - and getting you arm up was the tough part."]
[Jones - "So you didn't have to lean forward and pull your PLSS off of the seat."]
[Duke - "Not that I remember."]
143:31:31 Duke: 164. (Pause)
[As indicated on the EVA-II contour map, which will be Charlie's primary reference during the traverse, the first segment of the drive had been planned to be 1.3 km on a heading on 173. Because John landed farther north and west than planned, Tony gave them a new heading of 162 at 143:25:20, which Charlie seems to have mis-remembered. Over a distance of a kilometer, the difference is a trivial 35 meters.]143:31:40 Duke: Okay, Houston. We're underway.
[Brian McInall has created a map (11 Mb) of the traverse from the LM to Station 4, using Lunar Reconnaissance Orbiter Camera (LROC) image M175179080LR as the base and adding Rover locations derived from the Hasselblad and Data Acquisition Camera (DAC; 16-mm motion picture) images taken during the drive, and from occasional segments of Rover tracks visible in the LROC image.]
[The complete DAC footage for the drive to Station 4 is available on the Apollo 16 DVD set available from Spacecraft films and from a 31 minute YouTube clip prepared by Diego Trystero.]
143:31:44 England: Okay, good show. And even with all of that extra there, you're only leaving 2 minutes late. Outstanding.
143:31:55 Young: You're kidding. (Joking) We must have forgot something, Charlie. (Laughing) That's all I got to say...
143:32:02 Duke: Well, everything's running. Okay. Tony, as we cross out to the west here - or south - we see a lot of these black rocks with the white phenocrysts.
[Charlie's photos for the first part of the traverse are AS16-110- 17870 to 17879. See Figure 6-6 in the Preliminary Science Report for the approximate locations at which the pictures were taken. The photos are available in strip form. In addition, frames AS16-110-17870 to 88 can be viewed as a slide show ( 3.2 Mb ) in PDF format.]143:32:17 Young: Also, we see big white rocks with black phenocrysts. How about that, Houston? Black glass, I mean. Excuse me. (Pause)
[See, also, a detail from Brian McInall's traverse map that includes the 17870-9 camera stations (1.3 Mb.]
143:32:32 Duke: Okay. We've got a great view of all the way into Stone. We're right up on a ridge here, Tony. We're at 10 degrees bearing, 1.1 range.
[Charlie has mis-spoken. The range to the LM is 0.1 km.]143:32:40 Duke: There's a 1-meter boulder to the right that's very angular, that's just as we've already described: the black with the whitish inclusion. We can see all the way to the base of Stone Mountain and Survey Ridge. There are some secondaries around. The terrain is covered with about 3 percent of the surface with cobbles up to 15 centimeters. A couple of indurated little secondaries...
["Cobbles" are pieces of rock between about 6.4 cm to 25.6 cm.]143:33:17 England: And Charlie, verify the DAC is on.
["Secondaries" are craters formed by ejecta from other impacts; and an "indurated secondary" is a secondary which produced ejecta in the form of fragments of compressed regolith.]
[Jones - "Do you have any recollection of how Survey looked. I gather it was well up off the local terrain."]
[Duke - "Well, it was visible. We were sort of going downslope and it was just a big ridge up there. You know, it looked like we were going to have to go up like a rolling hill."]
[Jones - "Similar size to the ones around the LM?"]
[Duke - "Survey was bigger, taller."]
[We then looked at Figure 6-4 ( 648k ) in the Preliminary Science Report. The climb up Survey Ridge began when they entered the light-colored area northwest of the 'S' in Survey and reached the summit when they were about even with the "t" in Sunset. John then turned toward the southwest and drove along the ridge crest. What is unusual about this situation is that the shadows in the large craters clearly show that this picture was taken from the Command Module when the Sun was still relatively low in the eastern sky. Consequently, a ridge should be brighter on the east and darker on the west. The fact that Survey Ridge is brighter on the west is probably the result of South Ray ejecta preferentially impacting that side of the ridge.]
[See, also, Figure 6 in the South Ray Ejecta Distribution chapter of the Professional Paper.]
143:33:19 Duke: ...that are a meter or so (in diameter)...(Stops to listen) Yeah, I called DAC on.
143:33:25 England: Okay.
[Charlie probably reaches up to the DAC and, in process, knocks John's arm.]143:33:27 Young: Uh-oh, Charlie. Charlie.
143:33:28 Duke: (To Houston) I feel it running.
143:33:30 England: Good show.
143:33:32 Duke: Okay. Now, Tony, we're going down an incline - downslope - at 356 at 0.3, that is about...What would you say, about a 5-degree slope, John? And the boulder population and the cobble population has picked up over here to about 10 percent, I'd say.
143:34:00 England: Okay. There were those mounds mapped over at Phantom area. Can you see those...
143:34:02 Duke: I think we're just now coming up on...(Stops to listen) The mounds mapped where?
143:34:10 England: In the area of Phantom Crater. That will be to your left at about...It will be about 10 o'clock now.
[Phantom Crater is east of the outbound track at BX.3/83.0, and Tony may be asking about the irregularly shaped, closed contours surrounding Phantom.]143:34:18 Duke: No. Phantom Crater's over a ridge. I think we're coming by WC, is what we're really coming by. Off to our 1 o'clock...Make it 3 o'clock now, 350 at 0.3.
143:34:29 England: Okay.
143:34:32 Young: I think you're right, Charlie.
[John landed near CB.1/80.5 and a LM bearing/range of 350/0.3 would put them near BZ.6/80.8. They are probably passing northern Double Spot, rather than WC. The latter is at BX.8/79.9. Charlie's next picture is AS16-110-17876. The relevant portion of the traverse map includes the locations of 17870-79.]143:34:35 Duke: Okay. The largest blocks we see are a meter. The regolith seems to be loosely compacted, much like the regolith over at the...which is characteristic of all of the Cayley here. Most of the rocks are angular to subrounded.
143:34:59 England: Okay. Do you feel you're still in that ray?
143:35:02 Duke: (Lost under Tony) still in this ray.
143:35:05 LM Crew: (Answering Tony) Yep.
143:35:07 Young: Just covered with blocks and holes, Houston.
143:35:10 England: Okay. We copy.
143:35:12 Duke: Lots of secondaries, Tony.
143:35:15 Young: Charlie, what are we shooting for?
143:35:18 Duke: Well, we're supposed to be one seven...Let's see...
143:35:24 England: Okay. The heading on the first leg is 162.
143:35:25 Young: Houston, can you give us a range and first heading...(Stops to listen)
143:35:32 Duke: For 1.3.
[As indicated on the contour map, on the first leg they had planned to drive on a heading of 173 - revised to 162 - for 1.3 km until they reach Survey Ridge. As Charlie mentions in a moment, they will make a turn to the southwest once they get up on Survey Ridge and will drive along the ridge crest for a couple of hundred meters. As shown on the photographic map printed on the reverse of the contour map, they are planning to make the turn near BT.0/82.1. The bearing and range at that point was to have been 353/1.3 but, because the actual landing site is displaced from the planned spot, the bearing and range will be about 350/1.6.]143:35:34 Duke: Okay, we've got 0.6 now. When we get there, we should be 353 at 1.3. We're traveling a little bit east. I think if you...Now you look like you're headed just about for our spot. See Survey Ridge down there?
143:35:51 Young: Yeah.
143:35:53 Duke: Hey, this is a great place to keep this map. Wedge it in that camera. Yeow! Whooo! Man, that was a great big skid. We're doing 10 clicks, Tony.
143:36:06 England: Outstanding.
[The back end of the Rover may have broken out as the result of a turn to avoid a crater. McInall indates that the skid occured at about BY.7/81.2. Charlie's next picture is AS16-110-17877.]143:36:07 Duke: Still down about a 2-to 3-degree slope now. Old Barney's really driving this beauty.
[With regard to the skid and the accompanying LRV Visible Tracks inset, McInall writes "The yellow traverse track through this area (as with all areas of the traverse) was created in reference to the 16mm DAC footage. The version of the footage that I have (from the Spacecraft Films Apollo 16 DVD set, but also available on YouTube) has the audio nicely synched up for the most part. At the moment of the great big skid, you can visually see that the rover rotated counter clockwise to face more eastward. Unfortunately we don't see the tracks reflecting this. "]
[On the audio track, Charlie's "Yeow!" comes at 4:51 while, in the DAC sequence, there is a sudden discontinuity in the Rover heading at 4:56.]
[McInall "The width of a rover wheel track is right at the limit of resolution in the LROC imagery (0.4 meters /pix). That and lighting angle along with surface slope etc. probably all play a role in how and where we can see the tracks. Added to this, I believe that in places where we do see the tracks, it's either because for some reason the wheels were digging in and kicking up dust and there by lowering the albedo, resulting in dark “tracks”, or in other circumstances the wheels were packing down the surface in the right area such that with the right lighting angle was causing those tracks to reflect a higher albedo resulting in the appearance of light tracks. The traverse to Station 1 is (or will be) a good example of light (high albedo) tracks. Almost all of the traverse to Station 1 and back is visible in the LROC imagery, yet for EVA 2 this whole southern traverse barely shows any rack visibility."]
["In regards to the great big skid then, I think what we can see is that the dark patch just to the right of the bottom white arrow in the LROC inset, represents the spray of dust that might have darkened or lowered the albedo in that immediate vicinity. In other words we don't see the tracks but we do see the effect of the skid in terms of the dust that was sprayed out."] ["That being said, this particular LROC inset is probably one of the poorest example of visible tracks. However the first LROC inset south of Survey Ridge is a good example of both low and high albedo tracks which occur together over a distance of just 75 meters. There was no skid at this point but if memory serves John Young was reacting in a humorous way to the driving conditions at this point (143:54:25). To which Charlie says "I love it..." Anyway this is mostly speculation but partially based on the many hours spent staring at this wonderful imagery."]
[This is another reference to race car driver Barney Oldfield (1878-1946).]143:36:17 England: Do you have an Amps at max speed?
143:36:25 Duke: I can't tell you, I'm sitting in Volts right now.
143:36:29 England: Okay. Fine.
[As shown in Figure 1-22 in the LRV Operations Handbook, there is a switch near the middle of the console which allows the crew to read either battery voltage or current (Amps). Apparently, Charlie is unable to reach forward far enough to change the switch setting.]143:36:30 Duke: Tony, an observation here: the dust-covered rocks are mostly rounded. The angular rocks seem to be free of dust.
[Angular rocks are probably fresh ejecta, possibly from South Ray, while the rounded rocks are older and have been subject to more "weathering" due to micrometeorite impacts. Charlie's observation that the dust-covered rocks are the rounded ones suggest that the dust covering may also have been due to the South Ray event.]143:36:44 Young: And there sure are a lot of rocks, Houston.
143:36:50 Duke: Still as we described (earlier): cobbly. Cobble size is still the same. Maybe 10 percent of the surface, now. (Pause) Tony, we forgot to say it, but we're starting out with the correct (Hasselblad) magazines, as per checklist.
143:37:10 England: Okay. Good show.
143:37:15 Duke: Lot easier driving down here, isn't it, John? Not any real big craters. Lot of subdued...
143:37:22 Young: Well, it's not any easier; it's just that you can see what you're doing (driving cross-Sun).
143:37:25 Duke: Yeah. But it didn't seem to be as rough, is what I thought. Okay. We're at 348 at 0.8 now, Tony. (Pause) Still in indurated secondaries.
[They are near BX.2/81.3. Charlie's next traverse photo will be AS16-110-17883. A detail from Brian McInall's traverse map includes 17880 to 89. Frames AS16-110-17880 to 83 are combined in strip form.]143:37:46 England: Okay. You should be about halfway to Survey (Ridge).
143:37:52 Duke: Okay. Yeah, we see Survey right up there. That was properly mapped. (Pause) Most of the secondaries - or the craters - here, Tony, are in the meter size. Some of the larger ones may be 5 meters. Okay. It's getting a lot rougher now. A lot more hummocky: at 346 at 0.9. Slowing down to about 6 clicks. (Pause)
[They are near BW.7/81.6. Charlie's next traverse photo will be AS16-110-17884.]143:38:31 Duke: That's gonna be a steep slope up there, John.
143:38:34 Young: I believe it is, Charlie.
143:38:35 Duke: Up Stone. (Pause) Okay. We're looking for 35...About...Okay, at 1.3 clicks, we should be on Survey at around 35(0) or so. Looks like that's Survey dead ahead, to me.
143:38:54 Young: Looks like to me. (Pause)
143:39:02 Duke: Tony, apparently this ray is pretty extensive. We haven't got out of this cobble field yet, and we're now 1.0 at 348 (BW.2/81.5). And the percentages (meaning the fraction of the surface covered with small rocks) are just exactly the same. Characteristics of the regolith are identical; and it still appears loosely compacted. Almost like a freshly-plowed field that's been rained on.
143:39:38 England: Okay. We understand that.
[Charlie's next traverse photo will be AS16-110-17885. All of the crews noted areas of soil showing a "raindrop" pattern, undoubtedly produced by small, low velocity impacts.]143:39:43 Duke: Right now we're in an area, at 1.1 at 346 (BV.8/81.8), with four blocks that are meter to a meter-and-a-half size. Make that six blocks now. And off to our right, there's a slight depression that's maybe 20 meters below us, that extends over to a ridge that blocks out Stubby. (Pause) Okay, we're coming up to the biggest rock now we've passed on the traverse. Click. Got a picture of it. (Pause) And it looked like a breccia also, Tony. It was rounded.
[Frames AS16-110-17884 to 88 are combined in strip form.]
[Brian McInall indicates this picture is AS16-110- 17886.]143:40:34 Young: Aw, shoot, man.
143:40:36 Duke: Golly. Covered me with dust on that one.
143:40:39 Young: Sorry, Charlie.
143:40:40 Duke: That's okay.
[Jones - "When did you get sprayed with dust? When John made a sharp turn or when the back end broke out?"]143:40:42 Duke: That looks like a pretty good path off about 2 o'clock - 1 o'clock, John.
[Duke - "I don't remember. But the dust came from the front wheel - just flipped up."]
143:40:46 Young: Yeah.
143:40:49 Duke: Okay. Now the percentage of cobbles is picking up, Tony, at 1.2 at 344 (BV.3/82.2). And maybe now 20 percent of the surface is covered with cobbles up to 15 - make it 30 - centimeters, with the largest blocks being a meter size. (Pause) Looks like these larger ones are caused by...There's some craters here 5 meters or so that appear to me to be a series of secondaries right in this area.
[An example of a secondary crater - the product of a low-velocity impact by ejecta from an impact some distance away - is the crater just below the TV sunshade on the left side of AS16-110- 17884.]143:41:36 England: Okay. We copy that. You may bear back to the right about 10 degrees.
[Houston has noted that they are east of the planned track.]143:41:43 Duke: The rim of South...(Stops to listen) Okay, I think that's a good plan. Okay. We'll do that. You can still see the rim of South Ray, (which is) spectacularly white. It just stands out above the surrounding terrain by an order of magnitude (in brightness).
143:42:12 Young: Okay, what's the heading down Survey Ridge, where I think we are right now, Charlie?
143:42:15 Duke: Okay. We should be one...Okay. (As shown on the contour map) come down Survey at about (a heading of) 227 (for a distance of) 0.4(km). Yeah, this is Survey. Top of Survey, Tony, has got a lot of secondaries. Thirty percent of the surface with cobble (about 6.4 cm to 25.6 cm), predominantly in the 10-centimeter range, but some greater than that; up to 50 centimeters.
[Frame AS16-110- 17889 may show the climb up onto Survey Ridge.]143:42:43 England: Okay. Take plenty of Hasselblad pictures there.
[The frames covering the climb onto Survey Ridge and the drive along it, AS16-110-17889 to 907, can be viewed as a slide show (3.8 Mb) in PDF format. The camera station locations are shown in a detail from the traverse map.]
143:42:46 Duke: Very blocky.
143:42:50 England: Got plenty of film.
143:42:51 Duke: I'm clicking them off as fast as my finger'll pull the trigger.
143:42:53 England: Good show. (Pause)
MP3 Audio Clip ( 10 min 19 sec )
143:43:03 Young: Uh-oh; watch it, Charlie.
143:43:04 Duke: I got it. Okay. (To Tony) Okay; I'd say now, in this area, 70 percent is covered. 347 at 1.5.
[These coordinates put them near BT.8/82.3, which is a bit north of the mapped crest of Survey Ridge. Photos AS16-110- 17890 to 17895 show this very blocky area.]143:43:16 England: Okay; 1.5. That's where we mapped you on top of Survey...
[Frames AS16-110-17889 to 95 are combined in strip form.]
143:43:18 Duke: Tony, if we'd have gone...(Stops to listen) Okay. If we'd have gone to 353 on Survey originally, we'd have been down in a big depression. (Pause)
143:43:34 Young: I'm still pretty depressed at this point.
143:43:36 Duke: Oh, man, John. This is really a ray; it just goes right in to South Ray.
143:43:40 Young: Boy, you just can't believe the blocks, Houston. The block population on Survey, what is it, 50 percent?
143:43:47 Duke: Oh, I would say, estimating, 60 to 70. And you can track it right in, up across (and) over the ridge that blocks out Wreck and Stubby (and then) into South Ray. We're going downslope now, off of Survey; still heading southeast. (Pause)
143:44:25 Young: Got to get out of these, Charlie.
143:44:27 Duke: No. I think...Yeah, the Rover's hacking it with no sweat over these little ones.
143:44:31 Young: Yeah, but I mean (garbled) spend the rest of the day in that rille...(correcting himself) ray.
143:44:39 Duke: Yeah. I think you can hook a right here a little bit, John. Looks pretty good. (To Tony) There's really a lot of craters here, Tony, at 1.6 at 348 (BT.3/82.2). The top of Survey is just pockmarked. They're pretty subdued, though. We can drive through them up to 3-meter ones with no problem. (To John) You're still making 6 clicks, John. (Pause) (To Tony) The characteristics of the rocks, Tony, are the same as around the lunar module.
[They are near the locations of AS16-110-17898 and 17899.]143:45:13 England: Okay. (Pause) If you get a chance to look at the southeast side of Survey...
143:45:23 Duke: That's one of the white ones...
143:45:24 England: ...you might see if you see any beds in there.
[As was the case with the EVA-1 traverse, there are scarps mapped on the southeast side or Survey.]143:45:31 Duke: No, not a chance.
143:45:33 England: Okay.
143:45:36 Duke: It (meaning Survey Ridge)'s pretty well-rounded, Tony, and it just...The only predominant feature here is this ray pattern with all the secondaries.
143:45:44 England: Okay.
143:45:46 Young: Best set of rocks you ever saw, I'll tell you that. (Pause)
143:45:55 Duke: Boy, it'll be no trouble sampling the South Ray at Station 8; it looks like that this ray goes right across it.
143:46:03 England: Very good.
143:46:07 Duke: We're 1.7 now at 352 (BS.7/81.7), and sort of back down in...Almost...We've dropped maybe 20 meters. Just passing a secondary that's 10 meters across.
[The indicated location is roughly 50 meters from the track Brian McInall determined from the Hasselblad images and the DAC film. This is the largest difference seen on this traverse. One possible explanation is that Charlie's report of the coordinates was wrong.]143:46:23 England: Okay. You should see Merriam over to your right (at BQ.9/80.7).
143:46:30 Duke: Merriam would be down over the ridge.
143:46:33 England: Okay.
143:46:35 Duke: Man, there's a great split boulder right there. (Chuckles)
143:46:40 Young: (Laughs) Charlie.
[Brian Mcinall identifies this boulder as one visible in the map at BT.0/81.6, just beyond the plotted location of 17903. John's laugh and tone of voice suggests that he isn't impressed by the size of the split boulder and, perhaps, wonders why Charlie would think it worth mentioning.]143:46:42 Duke: (Chuckling) It is. That was (a rock with) an east-west split there, Tony. (Pause) Very undulating terrain, hummocky. The hummocks are, oh...
143:47:01 Young: What should our heading be down here now, Charlie?
143:47:04 Duke: Okay. We've still got to go three...This is the one that's two...From here up over is...
143:47:11 England: 168.
143:47:12 Duke: ...227 for 0.4. We should be 005 at 1.6 to cross...Then we turn south again.
[As shown on the contour map, They planned to drive 0.4 kilometers on a heading of 227 until they reached a bearing and range of 005/1.6.]143:47:25 Duke: We're at 1.8, but that's because we're a little...(Pause) I think we could go straight for them, John. There's Cincos, right up there on the hill.
143:47:37 England: All right. We think you could just about head south now...
143:47:39 Young: I think we should go straight for them; I want to get out of this ray.
143:47:44 Duke: (To Tony) Okay. We are. We're going 180. This is terrible, this ray, isn't it?
143:47:50 Young: Yep. That's why I want to get out of it.
[Jones - "Did John have to pick his way around rocks?"]143:47:52 Duke: Yeah. (Pause) Okay. We must be coming to the edge of it. My estimate of the cobbles is back down to about 20 percent now. (Pause) We have secondaries within secondaries. The predominant crater size is still (one) meter or so. Only a very few of the secondaries are indurated. Coming up on one now at 2.0 at 355 (BR.1/81.4). (Pause)
[Duke - "Yeah, we had to pick our way through it. It was a significant surface coverage of these boulders and we were just navigating around. It was tough on him."]
[Jones - "Let me get an estimate of the average speed on this trip. I don't imagine it was terribly quick through here."]
[Duke - "Well, no; it wasn't. You could compare...Let's see. Just look at the times here. At 46:07 we're 1.7/352 and at 48:35 we're coming up on 2.0/355. So that's 0.3 km in (2 minutes 28 seconds)...That's pretty good. (7.3 km/hr)."]
[They haven't been driving directly away from the LM and, making allowances for the changing azimuth, the average straight-line speed in this part of the traverse is 7.7 km/hr. As indicated at 143:52:23, their average speed over a longer portion of the drive on Survey Ridge is 7.1 km/hr.]
[In another minute, Charlie gives a speed readout of 8 km/hr.]
[Charlie's next photo is AS16-110- 17909. The frames covering the drive to the base of Stone Mountain, AS16-110-17908 to 917 can be viewed as a slide show ( 4.5 Mb ) in PDF format. These camera stations are included in the next map segment].143:48:35 Duke: Boy, isn't it something?
143:48:36 Young: (Laughing) This is really something!
143:48:38 Duke: You're still going 8 clicks, though, John. We're right on. Okay. (Pause) Tony, apparently, we're still on Survey. It's a wide ridge that's furrowed parallel to the long axis. (Pause) (Looking up at Stone Mountain) Now there's a big crater off to the right, John; and here's five right up here at about 12:30. The Cincos are right south of Crown, though; so it's the ones to the right where we want to go. See that big crater up there below Crown?
143:49:23 Young: Yeah.
[Crown Crater and the Cincos are marked in detail from a portrait of Stone Mountain constructed by the U.S. Geological Survey from 500-mm photos Charlie took at Spook Crater (Station 2). Although Spook is about 2 km NNW of their current location, the line-of-sight to the Cinco Craters is about the same. The photos of particular relevance are AS16-112- 18200, 18228 and 18229.]143:49:24 Duke: Okay. Now you're headed right for it. And the Cincos are right to the right of that. Apparently. In fact, that big one is probably Cinco 'e'.
143:49:37 England: From where you are, Cinco should be right in line with Crown.
143:49:39 Duke: It is, Tony. Right now. We got it spotted.
143:49:45 England: Okay.
143:49:48 Duke: Got a little crater in the inner flank. Okay; doing 10 clicks, and still in the crater-saturated downslope of Survey Ridge at 354 at 2.2 (BQ.2/81.6). Block population is still the same. Looks like we don't get out of the ray, really, until we hit (the base of Stone Mountain) and start climbing upslope at Station 6.
[Their current location is near the 17914 camera station. The 'little crater' is labelled in a detail.]143:50:21 Young: Houston, the best idea I can give you of what this (cobble-covered ray surface) looks like, is it looks like about halfway up to that crater that we went to out at the Nevada Test Site (NTS). Man, I tell you, I've never seen so many blocks in my life.
[John is adding to his comments back at 143:47:39. He is probably referring to Schooner Crater, which was produced by 31-kiloton nuclear explosive buried at a depth of 108 meters in layered volcanic rock. The depth of burial was chosen to maximize the size of the resulting crater, 260 meters diameter and 63 m apparent depth. The ejecta blanket has a very high concentration of blocks. Schooner has long been recognized as an analog for lunar craters. As detailed in Phinney's document on astronaut geology training, The Apollo 14, 15, 16, and 17 crews all visited Schooner at various time between September 1970 and August 1972. John and Charlie did Rover traverses at Schooner on 27 October 1971 (p.248 in Phinney).]143:50:37 England: Okay. Sounds like that (trip to NTS) was a good exercise then.
143:50:44 Duke: Good exercise in driving.
143:50:47 Young: (Perhaps nosing into a crater) Oh, that was a baddie.
[On the audio track track in Diego Trystero's YouTube clip, John's 'baddie' is heard at 19:39. In the video at that same point in the Trystero clip, a pair of nearly-identical craters can be seen at just inside the right edge of the DAC frame. Brian McInall has identified this crater pair in the traverse map. Note that the time counter in Brian's screen grab reads 19:41, compared with 19:39 for exactly the same frame when watching the clip on YouTube with my iMac. Seven seconds later, at 19:46, the center of the image drops by about half the frame height compared with the adjacent frames, indicating that front of the Rover went into a crater, possibly at 143:50:47.]143:50:49 Duke: That (possibly the crater rim) hit on the floorboard. That's okay. Well, I'm even getting dust on my helmet. (Pause) Boy, this is neat; really neat. (Pause) (To Houston) Okay, now between us and the Survey, Tony, we really drop off again down to the base of Stone. We're going down about a 4- or 5-degree slope that's still, apparently, (covered with) ejecta. South Ray ejecta. We're down to perhaps 10 percent now on block frequency. The character of the regolith is still the same: loosely consolidated with a rain-drop pattern. It probably looks that way because of the Sun. I'm convinced of that. The rocks are mostly grayish with white clasts in them.
143:52:03 England: Okay, what's the bearing and range for that getting off the contact?
143:52:09 Duke: Okay, we'll give it to you. We're right now at 354 at 2.5 (BN.7/81.8). We're still in a block field. It'll be about another 2 clicks before we're out of it.
143:52:23 England: Okay.
[Although "clicks" is usually used as shorthand for "kilometers per hour", here Charlie means two clicks of the range indicator or 0.2 kilometers.]143:52:24 Young: Okay; I just don't think you can identify these things as contacts per se.
[Since the time they first entered the block field at about 143:40:49, they have driven about 1.3 kilometers in 11 minutes 20 seconds at an average straight-line speed of 7.1 km/hr.]
[They are near the location where Charlie took AS16-110-17920]
[The next segment of the traverse map covers 17917 to 17928.]
143:52:29 England: No, we understand.
143:52:30 Young: They just fade out and then they go away. (Hearing Tony) Okay.
143:52:37 England: Okay, you're about 200 or 300 meters from the contact, as it's mapped, with the Descartes. Or the feathering out there. We'd like you to keep an eye out for any changes in regolith.
[This is the solid white line which runs roughly southwest to northeast in this part of the traverse map. The planned traverse path crosses the mapped location of the contact at about BL.44/81.8]143:52:52 Duke: Okay, you got it, babe. And I think that's a pretty good guess as far...At least, that's where the slope of Stone starts. (To John) That Stone Mountain looked like it was right on top of us, and we've come 2.6 kilometers and it still looks just as far away.
[During their second EVA, the Apollo 17 crew crossed a contact between a dark mare surface and the fringe of an avalanche outflow. From orbit, the albedo change is dramatic but, on the ground, the change is very subtle and shows up, primarily, in the brightness of the inner walls of small, fresh craters.]
143:53:09 Young: Yeah, it's really something. (Pause)
MP3 Audio Clip ( 9 min 40 sec )
143:53:15 Duke: Okay, Tony, characteristics are still the same as up on Survey. Ten percent cobbles, about the same size; maybe a smattering more of the larger ones, 50 centimeters and up. (Pause) Some of the rocks seem in good shape - hardly fractured - others appear to be badly fractured, but still homogeneous.
143:53:50 England: From your description, it sounds like we won't have any trouble finding split boulders at (Station) 8.
143:53:58 Duke: Well, I don't know. The...
143:54:02 Young: I haven't seen but one split boulder so far. Not that I've been looking; but I would if there were some.
143:54:12 Duke: Hey, that was super. That wheel just left the ground. (Pause)
143:54:23 Young: (Laughing) This is the wildest ride I was ever on.
143:54:25 Duke: I love it. It's great! Eight clicks, Tony. We got up to 12 there, once. We're at 355 at 2.8 (BM.2/81.7). Still have Crown and Cinco 'e' in sight.
143:54:45 England: Sounds like you're really making money there.
[They are about midway between the AS16-110-17926 and 17927 locations. On the way back down the mountain, they will do Station 6 about 200 meters west of 17927, at about BL.8/80.8.]143:54:47 Duke: Okay, we got to go over another depression - down through another depression - before we hit the upslope. That's about 100 meters in front of us. (Pause)
[Jones - "Did you spend a fair amount of time in the air because of the bumps?"]
[Duke - "It was like you were in slow motion as it bounced, because of the one-sixth gravity. I mean, we didn't spend a lot of time in the air, but you had that springy feeling that was more a slow motion (and) slower frequency because of the light gravity. And I think the suspension system was, probably, lighter than you would have down here. We called it bouncing, but we really weren't bouncing. Occasionally, the wheels would come off; but we'd just oscillate, really."]
[The 16-mm movies Charlie took of John's Grand Prix drive give an indication of the ride, albeit at larger amplitude because Charlie wasn't on board.]
143:55:04 Duke: Boy, it's a spectacular view looking out to the west, Tony. In fact, it looks like a whole mountain itself back to the west.
143:55:13 Young: Yeah, I think...
143:55:18 Duke: And that poop about being able to see the LM all the way on Traverse 2, I think, was gonna be bum dope. We've come down some big swales.
143:55:30 England: Okay.
143:55:31 Young: They may call them swales in your part of the world, Charlie. They call them mountains in mine.
[John grew up near Orlando, Florida - long before Walt Disney World made the area a tourist mecca. The highest natural elevation in Florida is only 345 feet (105 meters). In the Orlando area, there are no natural elevations anywhere near that high. See, also, the discussion following 144:49:40.]143:55:36 Duke: Yep. Okay, and in my 9 o'clock position (east), out about a kilometer - and we're 355 at 3.0 (BL.2/81.8) - is a tremendous boulder that must be so far away, but it's very predominant on the skyline. Must be 5 meters or so. (Pause) The next segment of the traverse map covers 17927 to 17935. They are near the 17929 camera station. [Charlie may be getting the hang of estimating sizes and distances. The Apollo crews usually underestimate sizes and distance, probably because of the lack of any atmospheric obscuration which, on Earth, helps us estimate distances. Here, Charlie has probably overestimated the size and distance of the boulder because, in a blow up of a CSM pan-camera frame which shows the LM and numerous large boulders on the rims of South Ray, North Ray, and other fresh craters, there are no visible boulders east of their current location. The LM is seven meters tall and, at the time the pan-camera frame was taken, the sunlit east face of the spacecraft and its shadow are clearly visible. Consequently, a 5-meter boulder east of their present location would also be visible. This implies that the rock is comparable in size to the boulder near the ALSEP, which is about 2 meters in size and is not visible in the blow-up. Even though Charlie has overestimated the size and distance, he seems to have taken a step toward eliminating obscuration as an element in the estimation processes.] 143:56:11 Duke: I can't give you any new words, Tony. The regolith is still the same. We're still in a block field. We're just about to start upslope here. Have we been climbing, John?
143:56:25 Young: Nope.
143:56:26 Duke: Look at that pitch meter.
[Young, from the 1972 Technical Debrief - "The pitch meter broke off almost before we started up Stone Mountain. The pitch meter face fell off. The only way you'd know it is that you'd only be making 8 kilometers per hour (but) you'd have the thing fire-walled. On a level, you could do 11 clicks; and, downhill, if you took the power off, you could do as much as you wanted to, if you let the thing go."]143:56:30 Young: Maybe we have been climbing. I doubt it.
[See, also, the discussion about the pitch meter at 144:08:20.]
[Training photo KSC-71PC-743 gives us a view of the meter, which is mounted on the outside of the console on John's side of the Rover. In the picture, it is in the pitch position. The dialog indicates that Charlie could read the meter from his seat. See, also, training photo S72-33685.]
[Duke, from the 1972 Technical Debrief - "Going upslope, the pitch meter needle was working and it was pegged at the top."]
[This indicates they were climbing more than a 20-degree slope.]
[Young, from the 1972 Technical Debrief - "Charlie said it was pegged and I said, 'Oh, Charlie'. I didn't believe this. I didn't feel as if I had a sensation that it had been pegged."]
[Duke, from the 1972 Technical Debrief - "On these local slopes that got steep, you really had no sensation of climbing a steep slope (in the Rover). But you really knew it when you were going downslope (on) a steep slope. (Going uphill), the thing could have gradually increased to a 25-degree slope and I don't think we would have realized it."]
[The other Rover crews reported similar sensations.]
[Young, from the 1972 Technical Debrief - "I tell you one thing, we couldn't have gotten out and worked on a 20-degree slope. You just can't handle it. Although, I think maybe we did when we were standing in that crater (at Station 5). We might have been on a 20-degree slope."]
[Duke, from the 1972 Technical Debrief - "I think so, too."]
143:56:33 Duke: Pegged out high.
[Charlie's photos taken during the initial part of the climb are AS16-110- 17918 to 17931. This sequence can be viewed as a slide show ( 5.9 Mb ) in PDF format.]143:56:36 England: Okay. Charlie, we'd like...
143:56:38 Young: (Lost under Tony)
143:56:39 Duke: Here it comes.
143:56:39 England: ...that DAC on 12 frames per second.
143:56:42 Duke: Okay. 12 frames a second, coming up. You got it.
143:56:49 England: Okay.
143:56:52 Duke: Okay, you're looking right at Cinco and...Tony, we've really been...It doesn't feel like we're climbing, but we've been climbing for quite a while here. I just looked at the pitch meter, and it was pegged out a minute ago.
143:57:07 England: Wow.
143:57:08 Duke: We're climbing up about a 10-degree slope now.
143:57:12 England: Okay.
143:57:14 Duke: And let's see, 6 was at 000 at...
143:57:21 Young: Charlie, what should we be heading for?
143:57:23 Duke: Those craters up there.
143:57:24 Young: Oh, don't tell me that. Where?
143:57:26 Duke: Okay, see that one that's sort of a funny shape. Looks like it's got a breach in the southeast side at 12 o'clock?
143:57:32 Young: Yeah.
143:57:33 Duke: That's it.
143:57:35 Young: That one at 12 o'clock, huh?
143:57:36 Duke: Yeah.
143:57:37 Young: Okay. Well, Houston, now that we get up to Stone...I mean up Stone Mountain, my assessment is it's not any worse than what we've been driving down.
143:57:50 Duke: I think this is one of our benches here, John.
143:57:53 Young: Think it is, huh?
143:57:54 Duke: (Looking at his copy of Figure 3.6.2-2) Yeah, we're at 3.3 (km range), and (Station) 5 should be at 33 and...Okay, Tony; we're on a flat area now at 355 at 3.3 (BJ.7/81.9), and I think it apparently is a bench. We're passing (the planned location of) Station 5; a little to the east.
[Charlie's next photo will be 17935.]143:58:15 England: Okay, glad you can recognize it there.
[The planned Station 5 location is at a range/bearing of 3.3/358 relative to the planned landing site at CA.0/81.0, so the planned Station 5 location was BK.5/81.6. However, Charlie seems to be ignoring the fact that they actually landed at CB.1/80.5. John and Charlie know that the decision about exactly where they stop to do Station 5 will be theirs to make on the trip back down the mountain.]
143:58:16 Duke: Yowie.
143:58:17 England: That's great.
143:58:21 Duke: And it's...I tell you, it's just as blocky here...The block population is up again to about 40 to 50 percent.
[Pictures taken during the next part of the traverse are 17934 to 17944, as marked in the next map segment.]143:58:30 England: Okay, you might look for a fresh crater that would punch through that ray material in the Descartes for Station 5 when you come back.
[The geologists would like to get samples of the Stone Mountain bedrock - known formally as the Descartes Formation. The surface is undoubtedly covered with South Ray ejecta and the best place to sample the Descartes would be on the rim of a fresh crater large enough to have punched through the South Ray material. In other words, they are looking for something similar to Apollo 15 Spur Crater, which was on the flank of Mount Hadley Delta.]143:58:40 Duke: Okay, most of the craters here are...There's another split one, but it...
143:58:48 Young: Look at old South Ray, Charlie.
143:58:50 Duke: That's beautiful. Just spectacular! I can't believe it. (Pause) And there's Baby Ray, John.
143:58:58 Young: See it?
[Photo AS16-110- 17945 shows Baby Ray, although Charlie doesn't take 17945 until they are maneuvering to find a suitable parking place at Station 4. During the drive to Station 4, they are on a southerly heading. See, for example, Figure D4f23 in the Professional Paper. They have been driving more or less directly from the location they picked out for Station 5 as they drove past to the place they will park at Station 5. Baby Ray is west of them. Although Charlie can't turn his suit of helmet, he can turn his head in the helmet and get a view of Baby Ray. John is too busy driving and watching for hazards to turn his head that much.]143:58:59 Duke: Yeah, you can see it. And it's got black sides to it. (Pause) Okay, here's a crater, Tony - remind us (on the way back down the mountain that it is) at 354 at 3.4 (BJ.2/82.3) - that's about 15 meters across and about 5 meters deep, and I'll bet you it punched through.
[Although there is some uncertainty as to their exact map location, they should be able to return to this crater using the Nav system. They do so at 145:11:04. When Charlie takes 17936, they are about one crater diameter northeast of the crater's center. Its diameter is very close to 15 meters.]143:59:19 Young: Oh, man, this...
143:59:22 England: Okay, we'll keep that in mind.
143:59:25 Duke: And that should be a good Station 5.
143:59:29 England: Okay.
143:59:30 Duke: Man, we are really going up a hill, I'll tell you.
143:59:34 England: How about the traction?
143:59:35 Young: (Lost under Tony) Crown.
143:59:36 England: Are you slipping at all?
143:59:37 Young: That's the only one I see I recognize.
143:59:39 Duke: Okay. See, over here by this oblong one - which I think is Cinco 'e', John - we go up a steep slope, but then it seems to level out right up on top.
143:59:48 Young: Yeah.
143:59:49 Duke: Okay?
143:59:50 Young: Yeah. Look at that bench in Crown.
143:59:52 Duke: I know it. No, we can't see Crown now.
143:59:55 Young: What is that thing with a V in it?
143:59:56 Duke: That's Cinco E.
143:59:59 Young: The one with the V in it?
144:00:00 Duke: Yeah.
144:00:02 Young: Let's go sample it.
144:00:04 Duke: Okay, that's what I was thinking. See, it seems to be it's a steep slope going up to it, but it looks like a bench or a little ridge on top. Okay, we're at 354 at 3.6 (BH.2/82.4). (Pause) And you ought to see that Baby Ray, Tony. It's got a real good raised rim. You can see some good...It's got lots of blocks around it that are hard to estimate the size.
[Baby Ray Crater is about 150 meters across and is shown in two 500-mm frames - AS16-112- 18253 and 18254 that Charlie will take from Station 4. Most of the visible blocks appear to be less than 5 meters across.]144:00:36 Duke: And we are going up a steep, steep slope, John. I'll tell you.
144:00:38 England: We believe you, Charlie.
144:00:40 Young: (Subvocal) We are not.
144:00:43 Duke: And it's got black streaks coming out of it. Okay, our Amps are now up to 60. Well, wait a minute. That's Volts.
144:00:55 Young: Yeah, Charlie.
144:00:58 Duke: This is going to be spectacular!! I can see Wreck and Trap and orange juice (on the inside of his helmet). (Pause) Golly! There's a little bench on up there, a little bit more, John.
144:01:17 Young: Yeah, we're getting up on a bench right now.
144:01:19 Duke: (Excited, even for Charlie) And, boy, this is going to be such a spectacular view, you can't believe it. Okay, we're at Cinco, Tony, we feel, at 3.7 at 355 (BG.7/82.1).
144:01:35 Young: See it anywhere, Charlie?
144:01:37 Duke: What? Cinco? Yeah, this is it. Here's the one, there's one, and the big one is just to the left over there with the V in it.
144:01:43 England: Charlie, you probably are at one of the lower Cincos (meaning Cinco 'a', 'b', or 'c', not 'd' or 'e'. You should have (a range from the LM of) something like 4.0.
144:01:52 Duke: Okay. We'll go on up.
144:01:59 Young: A little easier driving uphill than down as far as...
144:02:02 England: And you're well ahead on the timeline. You've been making good time.
144:02:04 Young: (Lost under Tony) just as long as you're going up.
[Thirty five minutes were allocated in the timeline for the drive to Station 4 and, to this point, they have been underway for about 31 minutes. They have driven a straight-line distance of about 3.8 kilometers, and their average speed is about 7.35 km/hr.]144:02:07 Duke: Tony, I can see into...
144:02:10 Young: Charlie, let's go up here to this big blocky crater. Man, that's really good.
144:02:13 Duke: Where's that?
144:02:14 Young: Right up there.
144:02:15 Duke: That's Crown.
144:02:16 Young: You don't want to go up to there?
144:02:17 Duke: Yeah, that's fine with me. Look's like a pretty steep slope.
144:02:21 Young: No, it's not. (Brief Pause) It might be. (Pause)
144:02:30 Duke: I don't think I'm going to be able to see Stubby from...
144:02:35 Young: Can you see it from here?
144:02:36 Duke: Yeah, I can see it now. Boy, it's a bad place to stop here. (Pause)
MP3 Audio Clip ( 7 min 02 sec )
144:02:49 Duke: We're in a pretty good right roll, Tony. About 5 to 10 degrees right roll, and climbing up a steep, steep slope. (Pause) And, John, here's a great bench right up here. It might be a crater. Just right in front of us about 20 meters. Why don't we stop there?
144:03:09 Young: Right up there, you mean?
144:03:10 Duke: I'm talking about really right here. See this big block at about 1 o'clock - at 12:30?
144:03:18 Young: Right here?
144:03:20 Duke: Yeah, right here.
144:03:24 Young: (Lost under Tony)
144:03:24 England: Okay. We concur with whatever blocky crater you want to stop at up there.
144:03:27 Duke: (To John) Okay, go ahead, go ahead.
144:03:31 Young: Okay, because it's on a flat bench, too.
144:03:32 Duke: Yeah. Okay, we're at 4.0 at 355 (BF.2/82.2).
[This is as far as I've gotten comparing the transcript with Brian's maps. 4.0/355 is well south of Station 4. Either Charlie mis-read the range or they've had considerable wheel slippage.]144:03:33 England: And go ahead and park for a Nav update down-Sun, if you can find a level place.
144:03:40 Duke: Okay, super. And, Tony, I think we're up at just about to Crown Crater.
[Crown Crater is actually about 800 meters southeast of them and farther uphill.]144:03:46 England: Okay. The main thing is to make sure that we have a crater that's big enough...
144:03:52 Duke: Maybe not.
144:03:53 England: ...to punch us through any ray material from South Ray.
144:03:57 Duke: This one does. Don't worry. This is a 10-meter crater that's got blocks on the inside of it that are partially covered with fillet material.
144:04:08 England: Okay.
144:04:09 Duke: And that's at 354 at 4.0 (BF.2/82.7). Hey, John. How about hooking left. (Garbled) Hey, this is going to be pretty good. Now I think we're going to be surprised...Look at those blocks, John!
144:04:25 England: We think you're at one of the sharp (rimmed) Cincos.
144:04:26 Duke: Wow, that was a good choice. (Responding to Tony) I do, too. Hey, can't we get up there closer, right in that block (field), John? So we won't have so far to walk. Upslope. Seems to be a flat place about right up here.
144:04:47 Young: Yeah. This almost flat?
144:04:50 Duke: Well, according to the pitch meter, it's not. It's pegged out. (Chuckles)
144:04:57 England: Hey, fellows, Ken was just flying over, and he saw a flash on the side of the Descartes. He probably got a glint off you.
144:05:06 Duke: Yeah. That's us. Man, those mirrors are dusty.
144:05:14 Young: I'm going up here, and set it in a crater so it doesn't go anywhere. (Pause)
144:05:26 Duke: This looks pretty good. I don't think it (meaning the Rover)'s going to go downslope. Tony, you can't believe it, this view looking back to the east (means "north"). We see Ravine (Crater, which is about 2 kilometers east of North Ray Crater), we see the rim of North Ray that's got some really good blocks on it. (To John) Look at this slope. Look at what we have been coming up. Man. (To Tony) But we cannot see into North Ray; it's above our position.
144:05:54 England: Okay.
[Charlie may have taken AS16-110- 17945 at this point.]144:05:55 Duke: We can see the old lunar module! Look at that, John. Okay, 270 on the (Rover) heading.
[Duke - "(Looking at the picture) Looks like we've just driven up the thing and just turned around. I remember that, up on the side of Stone Mountain. We came up and made a turn - really impressive - and then started back down a little bit. We were trying to find a bench that we could work on. And then we ended up pointing the Rover almost like northwest."]
[Brian McInall's planimetric map of the approach to Station 4 has south at the top and indicates that, before Charlie took 17945, John made a tight 360-degree turn to the left so that they were heading in a northwesterly direction. A labeled version of 17945 shows the place where John will park the Rover just beyond boulder 'B8'. See, also, MacInall's Station 4 planimetric map.
144:06:04 Young: Okay, Charlie. I want to go back down there and park in that crater right there.
144:06:08 Duke: Okay. Okay.
144:06:11 Young: See what I'm saying?
144:06:13 Duke: Yeah, okay. Looks like to me, from my side, if you just turn real sharp left, you'd have it. But that's fine with me.
144:06:19 Young: It's not flat, Charlie. It's pointing too downhill.
144:06:22 Duke: Not sideways, it wouldn't be.
144:06:23 Young: Huh?
144:06:24 Duke: Sideways. We got to park 270. (Pause) But that'd be fine. Why don't you go down there, John? You probably...(Pause) Watch that big rock! Ummm. Just cleared it. Which one are you going to park in?
144:06:52 Young: That one right down there, with that block in it.
144:06:54 Duke: The right?
144:06:55 Young: Yeah.
144:06:56 Duke: Okay. (Pause) That's a good overturnable one right there, John. Hey, we could roll that thing downhill. (Pause)
[The idea is to overturn and collect some of the soil that was underneath it. Presumably, that soil has been shielded from cosmic rays and the solar wind for as long as the rock has been in place and a comparison with nearby surface soil would yield information of soil/solar wind interactions.]144:07:26 Duke: Look at that beauty (meaning the Rover) climb over those 1-meter blocks.
[At about this point, Charlie takes his last traverse photo, AS16-110-17946. Note the large number of blocks and the Rover tracks coming uphill. Charlie's pan taken at 144:56:25 shows the tracks John is making as he drives downhill to the place where he will park the Rover.]
[Jones - Does this mean that John's getting the wheels up on..."]144:07:29 Duke: Okay. Just about got it. Just about...Great, great, super! Okay. We're parked, Tony, (reading the console) at (LRV) heading 270, (bearing to the LM) 354, (distance driven) 5.2, (range to the LM) 4.1, 100, 100, (Pause), 70, 68, 68, (Pause), 85, 100, off-scale...(correcting himself) about 200, 200, and 200, 200. And I'll give you the readings.
[Duke - "Up on some of the blocks, yeah. If I remember, they were more subdued blocks, though. I mean, it wasn't a boulder sticking up a meter, but the width and breadth of the block was a meter. It wasn't any problem. That car just really moved over all that kind of surface. I think we were probably ten or twelve inches off the surface - that's how much clearance we had. Maybe a little bit more than that."]
[Jones - "14 inches is the number that sticks in my mind."]
[Duke - "Yeah, maybe. So the rock couldn't stick up more than 14 inches or we'd drag the bottom - like we did a couple of times."]
[A bearing and range of 354/4.1 corresponds to a map location of BG.8/82.7, which is a position near the west rim of Cinco 'b'. Analysis presented in the 1981 USGS Apollo 16 Proessional Paper, such as MacInall's map of the approach to Station 4, shows that they actually parked about 80 meters west of the center of Cinco 'a', or at about BF.9/82.5. The difference between the indicated and actual locations is about 185 meters. Note that they have driven about 5.2 kilometers in order to achieve a range to the LM of 4.1. This is a higher ratio - or 'wander factor' - than many other Apollo Rover traverses and is due, in part, to the Survey Ridge excursion.]144:08:09 Young: Okay, Houston. We're in real bad shape because our vehicle attitude indicator in roll (is broken)...That's why you thought it was so pitched. The thing is broken, Charlie.
144:08:19 Duke: It is. Yeah.
144:08:20 Young: It's broken. See, it's flipped off up there. But as soon as we get the TV up, anybody would be able to tell where we're at.
[As is shown in Figure 1-26 from the LRV Operations Handbook, the pitch/roll indicator was mounted on a pivot on the left side of the console. During traverses, the pitch scale was normally in view but, when John parked the vehicle, he would re-position the indicator to show vehicle roll.]144:08:26 England: Okay. On the SSD (Sun Shadow Device), can you estimate a roll well enough for an update?
[The following is taken from the Apollo 16 Mission Report - "During the second EVA, the crew reported that the LRV pitch-attitude-indicator scale had fallen off. The indicator provides a vehicle pitch reference between plus and minus 20 degrees. The loose pitch scale did not impact the mission because the pointer for the indicator continued to work properly and the crew could adequately estimate the vehicle pitch from the pointer position. The pitch-attitude-indicator scale is bonded to a bracket (Fig. 14-81) which is attached to the indicator case. The scale is constructed of 2024T3 aluminum and the bracket is 6/6 nylon. A comparison of the coefficients of thermal expansion of the materials indicate approximately a 4-to-1 ratio for nylon-to-aluminum. With this expansion ratio, stress factors of safety for an ideal bond are 3 and 4 and temperatures of minus 100-degrees F and plus 250 degrees F, respectively. Although a review of the bonding procedures did not reveal any problems, a flaw most probably existed in the bond, and this allowed stress buildup which caused the scale to become unbonded. The crew experienced no difficulty in estimating the pitch angle after the scale became unbonded. The back of the meter case must be machined off to gain access to the scale, and special handling permits must be obtained before working on the meter because of the radioactive materials within the case. For these reasons, no hardware changes will be made for Apollo 17."]
[No problems were experienced with the Apollo 17 indicator.]
[As shown in Figure 1-22 from LRV Operations Handbook, the Sun Shadow Device was mounted between the heading and speed indicators. With the LRV parked facing west, the crew could raise the SSD as shown in Figure 1-27 and read the position on the scale of the shadow cast by the gnomon. This reading, combined with the known position of the Sun in the sky and the vehicle roll and pitch, allowed determination of the true heading. Don McMillan has provided an animation (2 Mb) of the Sun Shadow device being put in position to provide a reading.]144:08:37 Young: I think we're rolled about 4 degrees left, and we're pitched down about, oh, 5 or 6. (Lost under Tony)
144:08:45 England: Okay. And the SSD?
144:08:50 Duke: Okay. Sun shadow is 9...
144:08:56 Young: Nine degrees.
144:08:57 Duke: Left.
144:08:58 Young: Left.
144:09:00 England: Okay. We copied 9 degrees...
144:09:02 Young: (Lost under Tony)
144:09:02 England: ...And, Charlie, you want to check the DAC?
144:09:07 Duke: Okay. Checking it off. Stand by.
144:09:11 Young: Charlie, whatever you do, don't hit that brake.
144:09:14 Duke: Okay. (Pause) John, it's pretty level, it seems like, right here!
144:09:24 Young: Well, that's what I hope.
[During the second Apollo 15 EVA, Dave Scott and Jim Irwin stopped at a boulder at Station 6a on the flank of Mt. Hadley Delta but, because the boulder was on a slope of about 15 degrees and was resting on a very soft surface, they felt they were in a precarious position and only spent a few minutes before moving downslope to Spur Crater where they were able to park the Rover on a level spot on the downslope rim.]144:09:26 Duke: DAC's off, Tony.
[Jones - "Did you have discussions with the 15 guys about working on slopes and parking the Rover."]
[Duke - "I don't remember specific discussions; but I'm sure we did. Those discussions probably influenced us about where to park. We didn't want to park with the Rover on a steep slope because it's so hard to get out and to walk. So we wanted to get a bench - a fairly level place to work. If you're on a fairly level place, you can work pretty good."]
144:09:28 England: Okay, Charlie. And can we have your frame count?
144:09:33 Duke: Okay, the mag's empty on the DAC. (Pause) My (Hasselblad) frame count is 82.
144:09:41 England: Okay, we copy. Sounds good.
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