Apollo 15 Lunar Surface Journal

Stereo Photography at Station 10

Corrected Transcript and Commentary Copyright © 1996 by Eric M. Jones.
All rights reserved.
Last revised 9 August 2012.

MP3 Audio Clip ( 9 min 49 sec ) by David Shaffer

166:13:07 Irwin: Ready to go?

166:13:08 Scott: Okay. (Pause) Man, am I going to miss one-sixth g. This is neat. (Long Pause) Okay. I'm strapped in. You're strapped in. Soon as I can get the switches on here. (Pause) Okay, Joe, now you're going to have to say again where you want us to go, because...

166:13:56 Irwin: Just north, Dave, along the side of the rim.

166:13:58 Scott: I thought you said something about 3/10ths of a click, didn't you?

166:13:59 Irwin: Yeah.

166:14:00 Allen: That's affirm Dave. ...

166:14:01 Irwin: Okay. I'll tell you what, we were...

166:14:02 Allen: ...Just 3/10ths to 4/10ths of a click...

166:14:03 Irwin: ...

166:14:04 Allen: ...via the easiest route north, and all we need is the photography from the point where you stop.

166:14:13 Scott: Okay.

166:14:15 Irwin: Tell you when we get to 2.8, Dave. Distance. I'll let you know.

166:14:19 Scott: Okay.

[They drove a distance of 2.5 km to get to Station 9a and want to go 0.3 km north to get a second set of 500-mm photos of the west wall of the rille. The distance indicator will tell them when they've gone far enough along the edge of the rille.]
166:14:20 Irwin: (Clears throat)

166:14:24 Allen: And, troops...

166:14:25 Scott: Okay. We're moving, Joe.

166:14:26 Allen: ...what you're picking up is just the base for the stereo photography.

166:14:32 Scott: Right.

166:14:34 Irwin: It's fairly easy driving here, isn't it?

166:14:36 Scott: Sure is. It's a lot easier than the other place.

166:14:38 Irwin: Yeah. (Pause)

166:14:41 Scott: Fairly good soil.

166:14:44 Irwin: We're doing about 8 clicks. (Pause)

166:14:49 Scott: Look, there's a big one.

166:14:51 Irwin: We're heading 310 to 320.

[At Station 9a, they were parked on about a northwest (315) heading and are continuing in that direction. At 8 km/hr, they would cover 300 meters in about 2.25 minutes. They are approaching a group of boulders about midway between Station 9a and Rim Crater. In a labeled detail from a 30 October 2009 LROC image, M111571816R, the ":big one" may be the bright boulder with a prominent shadow on the east side of the group.]
166:15:00 Scott: You don't want me to run us over that big one there, do you?

166:15:02 Irwin: Please, no.

166:15:03 Scott: (Laughs)

166:15:06 Irwin: Take it easy on the old Rover. I'll get a good trade-in value on it.

166:15:13 Scott: Yeah. How much farther we got to go? I got to plan where we're heading here.

166:15:18 Irwin: About another 2/10ths to go; I'm reading...

166:15:20 Scott: Okay.

166:15:21 Irwin: ...27...Oh, another click, Dave. Maybe up by that large block at 12 o'clock (meaning directly ahead of the Rover).

166:15:27 Scott: Yeah.

[Possibly a boulder on the northwest rim of Rim Crater.]
166:15:28 Irwin: If you can negotiate that?

166:15:29 Scott: Gee, the one with the great big vesicles in it.

166:15:30 Irwin: Oh, notice that fresh one (almost certainly means a fresh crater) that's just this side of it? It looks like a light colored - almost a yellow - ray that extends to the west of it?

[Candidates for the large block with great big vesicles and the rayed crater are marked on the detail from LROC image M111571816R.]
166:15:37 Scott: Ooops. No, I can't now. I'm busy driving.

166:15:38 Irwin: Yeah.

166:15:39 Scott: (Laughs)

[Irwin, from the 1971 Technical Debrief - "The distribution of fragments seemed to be uniform along the edge of the rille. By 'uniform', I mean about 20 percent (surface coverage)."]

[Scott, from the 1971 Technical Debrief - "Yes. That is about right. And a variety of sizes from the 1- to 2-inch size up to the large, 1-foot to 1 1/2-foot size."]

[Irwin, from the 1971 Technical Debrief - "The fragment distribution probably was very similar to what we saw at the south side of Dune (near Station 4)."]

166:15:40 Irwin: Oh, and...

166:15:41 Scott: Keep talking.

166:15:42 Irwin: ...very fresh crater right on the rim of the...

166:15:45 Scott: Ooooh, look at this. This is one of the Twins!

166:15:47 Irwin: Yeah. It probably is, yeah.

[They are mistaken. South Twin is about 900 meters north of their current location.
166:15:48 Scott: Man, we're right at it, and it's a deep fella. (Pause) Keep a little momentum going here.
[The eastern/southern portion ( 5 Mb ) of Jim's Station 10 pan shows that they are driving around the eastern rim of Rim Crater. The "big vesicle" boulder may be the pair to the left of up-Sun. Note that the solar azimuth is 113. Consequently, the pair of large boulders is roughly 5 degrees south of east from the pan location.]
166:15:58 Irwin: Yeah. (Pause) There's a flat part over there to the left.

166:16:04 Scott: Yeah. Look at that great vesicular (rock) there. Looks exactly like...Uh, oh. Guess what we just lost again: the front steering. Oh, I know what('s wrong) There. Turn the switch on; it works a lot better.

166:16:20 Irwin: We're at 2.8, Dave. So (garbled)

166:16:22 Scott: Getting close, huh?

166:16:23 Irwin: Yeah.

166:16:24 Scott: Let me get to this level spot over here. Okay, up on the rim of the Twin there would be a great place to take a pan.

166:16:34 Irwin: Either that or over on those rocks over at 11 o'clock.

166:16:38 Scott: Yeah, maybe, maybe. (Pause) Do the rim of the Twin there. Okay. We stopped, Joe.

166:16:47 Allen: Okay, Dave. Thank you.

166:16:48 Scott: Why don't you read the coordinates, partner?

166:16:50 Irwin: Yeah. Okay; heading 310, (bearing) 093, (distance) 02.8, (range) 02.0, 90. 92, 102, and 110.

[The range and bearing suggest they are near BT.0/65.0. Application of the 8-degree bearing correction Dave suggests at 166:38:34 puts them BR.9/65.0. That location is in the rille just west of Rim Crater.]

[As soon a Jim gets off the Rover, he will take a pan from the north rim of Rim Crater. A comparison between frames from the pan and the 30 October 2009 LROC image ( 6 Mb allows us to get a location by triangulation. Jim's frame AS15-82-11184 shows three blocks in the near field. These near-field blocks, along with a number of blocks in the far rille wall, can be identified in the LROC image and give us one azimuth line from the pan location. Next, a line-of-site past some very large blocks on the near rim give us a second azimuth line. Finally, there is a line-of-sight over the center of Rim Crater to a distinctive, talus-filled crater in the far rille wall, which gives us a third azimuth line. Positioning of the line-of-sight to the talus-filled crater on the LROC image is more uncertain than the other two, but the combination clearly indicates that the pan location is on the north rim of Rim Crater.]

Figure 5-125 from the Apollo 15 Preliminary Science Report is a sketch map of Station10. The actual diameter of Rim Crater is about 45 meters. The version of the Station plan map on the Station 9a-to-10 traverse map has been sized so that the linear scale on the plan map agrees with a 45-m diameter for Rim Crater. The approximate LRV location relative to the pan location is chosen to be the same as in the plan map.]

166:17:17 Allen: Okay, Jimmy. Thank you. And thinking downstream, here, all we need is photography from this stop, and we're looking towards arriving back at the LM in about 45 minutes.

166:17:32 Irwin: Okay. Shoot! No time to go to the Northern Complex, huh?

166:17:36 Scott: Do you want TV, Joe?

166:17:38 Allen: Yes, please. (Pause; brief static)

[TV on. The camera is pointed at what appears to be the crescent Earth. After a while it becomes obvious that Fendell is unable to point the TV at anything useful. After Jim finishes his pan, he will come over and rescue the camera.]
166:17:43 Scott: You got it. (Pause) Hey, Jim, up on the rim. Right over here on the rim.

166:17:53 Irwin: Okay. The rim of...

166:17:54 Scott: Yeah.

166:17:55 Irwin: ...Twin.

Video Clip  2 min 58 sec ( 0.8 Mb RealVideo or 26 Mb MPG )

166:17:56 Scott: Right there on the rim. Then you get the crater and you can get all over the place. Then I can take the 500 from up there, too. (Long Pause)

166:18:56 Scott: Okay, Joe. The crater is very uniform. It has debris on the order of, oh, a foot or so almost throughout. No accumulation of talus at the bottom; and it's got fines covering everything, nothing really sharply exposed. And most of the fragments are subangular and it looks like non-vesicular, although I do see one highly vesicular one right in the bottom. And it's about 60 meters across and maybe, oh, 10 meters deep, smooth sides, and a very slightly raised rim.

[Rim Crater is about 45 meters in diameter.]
166:19:35 Irwin: Dave, let me tur...

166:19:36 Scott: Ooop. I'm sorry.

166:19:37 Irwin: I'll just complete this.

166:19:41 Scott: And, as craters go around here, it's deep. (Long Pause)

166:19:57 Allen: Jim, are you taking your pan, now?

[It is currently 11:54 UTC on 2 August 1971. The solar elevation and azimuth are 39.3 and 113.3, respectively.]
166:20:02 Irwin: Yeah. Pan's complete; and I'm...

166:20:03 Allen: Beautiful, and maybe you could give us a hand...

166:20:04 Irwin: ...moving a little bit to the north.

166:20:05 Allen: ...with the TV camera.

166:20:10 Irwin: Oh, okay. (Dave laughs) Looks like you're looking back at Earth.

166:20:17 Allen: Yes, sir, and our necks are killing...

166:20:19 Irwin: Can you see yourself?

166:20:20 Allen: ...us here. (Long Pause)

[Jim's Station 10 pan consists of frames AS15-82- 11165 to 11184.]

[Frame 11165 is a down-Sun toward Hill 305.]

[Frames 11167 and 11168 and show Dave coming south from the Rover carrying the 500-mm camera. David Harland has combined high-resolution scans of these in a mini-pan.]

[Frame 11169 shows the Rover at the left side.]

[Frame 11170 shows the inbound Rover tracks.]

[Frame 11173 shows the inbound Rover tracks coming in from the right.]

[Frame 11174 shows the Swann Range.]

[Jim took 11175 toward Silver Spur and Mt. Hadley Delta. The white-ejecta crater on the east rim of St. George is at the right edge. Note that, uncharacteristically, Jim did not get good overlap with 11174.]

[Realizing that he did not get good overlap, Jim turned to his left to fill the gap with 11176 and almost succeeded, leaving only a small gap at the left.]

[Jim took the pan from the north rim of Rim Crater. Frames 11177-82 have been assembled as a stereo mini-pan, with the non-stereo version presented for context ( 8 Mb ).]

166:20:36 Irwin: Well, there's a large block there just to the north of that, Dave. It looks like it might have a contact in it - between a dark, very vesicular basalt and that light-colored tan.
[Jim lowers the TV camera, giving us a view toward the northwest and Hill 305. Fendell pans left and, part way into Jim's transmission, finds him standing south of a waist-high boulder.]
Video Clip  2 min 52 sec ( 0.7 Mb RealVideo or 25 Mb MPG )

166:20:51 Allen: Thank you, sir. (Pause) Dave, are you firing off the big camera?

166:21:00 Scott: Yup. (Long Pause)

166:21:16 Irwin: I've got an angular fragment here, subangular, about 4 feet by 5 feet; and the vesicles that are facing to the southwest are very large vesicles, about 3 inches, 2 to 3 inches in diameter....

166:21:39 Allen: Amazing. Amazing.

166:21:40 Irwin: ...then there's a gradual...

166:21:42 Allen: Leave it there...

166:21:43 Irwin: ...transition...

166:21:44 Allen: ...though, Jim. The Rover's not stressed for it.

166:21:45 Irwin: ...gradual transition...(Laughing at Joe's joke) Oh, I'd love to bring it back. I guess I'll just take some close-ups here.

166:21:53 Allen: Yes, sir, please.

[Fendell zooms in on the boulder.]

[Scott - "That's a wild-looking piece of stuff, isn't it?"]

[Jones - "It sure is!"]

[Scott - "Goodness gracious."]

[During the 1971 Technical Debrief, Jim brought this vesicular boulder into the discussion.]

[Irwin, from the 1971 Technical Debrief - "The fragment distribution (along the rille edge between Stations 9a and 10) was very similar to what we saw on the south side of Dune."]

[Scott, from the 1971 Technical Debrief - "Yes."]

[Irwin, from the 1971 Technical Debrief - "Those two might relate very closely."]

[Here, Jim is suggesting that the rocks they saw and sampled near Station 4 at Dune Crater came from the same layers exposed along the rille edge.]

[Scott, from the 1971 Technical Debrief - "You are right. (But) those big blocks that had the jointing or the linear fractures in them did not have the vesicularity that big block did in the south side of Dune Crater. I don't remember seeing the 3-inch, large, well-defined vesicles (at Station 10), do you?"]

[Irwin, from the 1971 Technical Debrief - "Yes."]

[Scott, from the 1971 Technical Debrief - "In those big blocks (at Station 10)."]

[Irwin, from the 1971 Technical Debrief - "Yes."]

[Scott, from the 1971 Technical Debrief - "You think so?"]

[Irwin, from the 1971 Technical Debrief - "I documented one."]

[Scott, from the 1971 Technical Debrief - "Did you?"]

[Irwin, from the 1971 Technical Debrief - "It had the same size vesicles (as the Station 4 boulder)."]

[Readers can make the comparison for themselves. Frame AS15-82- 11185 is a close-up of the Station 10 vesicular boulder and AS15-87- 11773 shows the Station 4 boulder. To my untrained eye, the vesicles are comparable in size.]

[The following exchange suggests that Jim and Dave may have been talking about different Station 10 rocks.]

[Irwin, from the 1971 Technical Debrief - "The ones off in the distance, you mean?"]

[Scott, from the 1971 Technical Debrief - "Yes; the ones off in the distance."]

[Irwin, from the 1971 Technical Debrief - "It seemed that there were some large vesicles, but we really were not close around any."]

[Scott, from the 1971 Technical Debrief - "It did not look to me like it had the very large ones that we saw at Dune Crater. It was the same color."]

[Irwin, from the 1971 Technical Debrief - "You got some 500s that probably took in that field-of-view."]

[Scott, from the 1971 Technical Debrief - "I think so."]

[Readers should note that, as yet, I have not been able to confidently decipher this part of discussion. Part of the problem, of course, is that this was such a short stop that neither Dave nor Jim had much of a chance to do more than take pictures in the hope that they would provide interesting information.]

166:21:55 Scott: Got the tongs? Oh, you got your thing, yeah.

166:21:59 Irwin: I don't have my scoop; I'll estimate...

166:22:01 Scott: It won't work.

[Comm Break]

[Jim takes a stereopair of the large-vesicle block, AS15-82- 11185 and 11186. Eric Nelson has produced a dramatic red/blue anaglyph ( 598k ) of the right-hand portion of the boulder.]

166:23:05 Irwin: Just to the north of the large one I just mentioned, there're two other large fragments. And there's a fracture right between them, and they also have the large-vesicle pattern.

166:23:20 Allen: Rog, Jim. Copy.

[While Dave takes the 500-mm photographs, Jim takes more photographs of the Station 10 boulders. First, he moves north of the large-vesicle boulder to take a down-Sun, AS15-82- 11187, of another large rock north of it.]

[Next, Jim moves a few steps to his right to shoot a cross-Sun, 11188, over another Station 10 boulder. Note the rock that is in the background in both 11187 and 11188.]

[Next, Jim moves to a spot ESE of the boulder that was in the foreground in 11187 and shoots 11189 north across the boulder that was in the foreground in 11188.]

[Finally, Jim steps back and to his left and gets both the 11187 and 11189 boulders in 11190 toward the NNE.]

[Fendell pulls back on the zoom and watches Jim as he moves among the boulders.]

166:23:22 Irwin: Don't know whether we've sampled this (rock-type). And the material that has the large vesicles has long laths of probably plagioclase.

Video Clip  2 min 41 sec ( 0.7 Mb RealVideo or 24 Mb MPG )

166:23:35 Scott: How long, Jim? What's a long lath?

166:23:38 Irwin: Yeah, a long lath's about a centimeter.

166:23:45 Allen: Roger, Jim. We copy that. And as much as we hate to, we're going to have to get you aboard the Rover, heading back across the mare towards the east, please.

MP3 Audio Clip ( 2 min 49 sec ) by David Shaffer

166:23:55 Scott: Okay. (Pause) 500 (frame counter) says 155.

166:24:03 Allen: Good show, Davy. (Long Pause)

[Fendell starts panning clockwise. There are many more rocks on the surface here than there were at Station 9a.]

[Dave has taken sixty-eight 500-mm photos at Station 10. He starts with a series along the top of the west wall of the rille (assembly by Dave Byrne). The frames are AS15-89-12097 to 12116.]

[Frame 12097 shows the same outcrop seen from Station 9a in 12026. Note the difference in the relative position of this outcrop and Hill 305 in the background, showing that this picture was taken north of Station 9a.]

[Next, Dave takes five pictures of part of the west wall farther south (assembly by Dave Byrne), with no overlap with the first series. The frames are AS15-89-12117 to 12121.]

[Next, Dave takes a series of pictures of the debris-filled crater (assembled by Dave Byrne) in the west wall of Hadley Rille, starting with 12122. Note the large tetrahedral rock which is just left and below center; and, note also, the seat-shaped rock about two fiducials above the tetrahedral rock. Frame 12126 is the last frame.]

[Next, Dave takes a series (assembled by Dave Byrne) showing the mare surface beyond the rille and the upper parts of the debris-filles crater. The frames are AS15-89-12127 to 12131.]

[Frame 12127 is similar to 12122 but is aimed a little higher and to the right.]

[Next, Dave takes a second, short, right-to-left sequence (assembled by Dave Byrne) of the debris-filled crater. The frames are AS15-89-12132 to 12136.]

[Frame 12132 is similar to 12122. Note the large tetrahedral rock which is one fiducial right and one above the center of this frame. That rock can also be seen just left and below center in 12122 and also in 12060 and 12128.]

[Dave's next sequence is a vertical strip that includes the debris-filled crater. The frames are AS15-89-12137 to 12142.]

[Frame 12137 is similar to 12130.]

[Next, Dave takes two pictures of the top of the talus slope (assembled by Dave Byrne) somewhere south of their present location. These frames are AS15-89-12143 and 12144.]

[The next four frames show Trophy Point (assembled by Dave Byrne). The first three of these are AS15-89- 12145, 12146, and 12147 , which is similar to 12080. Note the large, blocky-rimmed crater on the mare surface above and to the left of center. Frame 89-12148 was taken below and to the left of 12147.]

[Dave Byrne has created a composite of the area around the debris-filled crater on the west wall. The frames are AS15-89-12122 to 12148.]

[Frames 12149, 12150, and 12151 show the talus slope on the west wall. Dave Byrne notes that the upper righthand corner of 12151 overlaps with the lower lefthand corner of 12097.]

[Dave now does a vertical sequence down the slope into the rille. The frames are AS15-89- 12152 to 12156.]

[Dave takes a three-frame vertical sequence (assembled by Dave Byrne) consisting of frames 12157 to 12159.]

[Frame 12157 is similar to 12104 and shows a portion of the west rim of Hadley Rille.]

[Dave Bryne has created a composite showing the West Wall outcrops. The frames are AS15-89-12097 to 12116 and 12151 to 12159.]

[Dave takes a left-to-right sequence (assembled by Dave Byrne) toward the south showing the slope into the rille from the east rim. The frames are 12160 to 12162.]

[Next, Dave takes AS15-89- 12163, which shows a small crater with dark ejecta that is southwest of Elbow Crater. This same crater can be seen in AS15-82- 11179 and is one fiducial above center and 3/4s of a fiducial left. Elbow Crater is further left, but very subtle from this perspective. Note that the dark-ejecta crater diameter is about half a fiducial spacing or about 0.01 radians. The distance to the crater from Station 10 is about 3.5 kilometers, so the diameter is about 35 meters.]

[Finally, frame 12164 shows the white-ejecta crater on the east rim of St. George Crater.]

166:24:53 Irwin: Getting ready to move out, Dave?

166:24:56 Scott: Yep. (Long Pause) Leave something here for the next guy.

[Scott - "When you go do this sort of thing, there should be a plan that says you follow up - that Dave Scott has to work on it for three years after the flight. Otherwise, you're not getting any return for your investment."]

[Jones - "Or as much return as you could. In putting together the Lunar Sourcebook, Grant (Heiken) and Dave (Vaniman) and Bevan (French) got the chapter writers - who are experts in particular fields - to pull together the work that people have done over the years. Certainly, we understand the Moon a whole lot better than we did before Neil and Buzz landed."]

[Scott - "Oh, absolutely! I'm not disputing that. I'm just saying that there should have been a long-term plan in place for analyzing the results. But everybody already knows that."]

166:25:26 Scott: Okay, hop on, and we'll get on with it here. (Pause) Get your ol' handy dandy seatbelt fixed up there because we'll be going all the way back. (Pause)
[Fendell reaches the clockwise pan limit and finds Dave and the LMP seat waiting for Jim. Fendell then reverses direction and starts a counter-clockwise pan.]
166:25:54 Irwin: Yeah, I'll hop on.

166:25:57 Scott: Okay. (Pause) Okay, TV's coming off.

166:26:11 Allen: Okay, Dave. Thank you.

[TV off.]
166:26:21 Scott: And TV camera'll be (pointed) aft and down.

166:26:24 Irwin: I knocked that seatbelt off, Dave, I'll have to get off and get it.

166:26:26 Scott: I'll get it.

166:26:28 Irwin: But you can't.

166:26:29 Scott: Oh, really? Okay, hop off. (Pause) Why don't you let me get it and hold it. (Pause) Okay, babe. Got it. (Pause) Too much back, Jim; you go back too much. Come to your right now. Come to your right. Come to your right. That's it. Now you're in. That's it, Jim. You're a tad too far back when you get on it. (Pause) Okay, you're in. (Pause)

[Jim took AS15-82- 11191 from the Rover at Station 10. A number of rocks in this picture can also be seen in 11167, which is part of his Station 10 pan. For example, in 11167, there is an elongated rock with a relatively bright sunlit face above Dave's right hand at shoulder level. In 11191, that rock is near the fiducial one right and one below center.]

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