Geology at Cone Crater

Geology Stations F and G

 

Back Down the Ridge to Station F

Corrected Transcript and Commentary Copyright © 1995-2017 by Eric M. Jones.
All rights reserved.
Scan credits in the Image Library.
Video credits in the Video Library.
Except where noted, MP3 audio clips by Thomas Schwagmeier and video clips by Ken Glover.
Last revised 19 December 2017.

RealVideo Clip (11 min 56 sec)

MP3 Audio Clip (Glover) (16 min 09 sec)
(The clip actually starts at 133:45:31.)

MP3 Audio Clip (Schwagmeier) (40 min 24 sec)

[Note that, until Al and Ed get back to the LM, the TV picture shows an unchanging scene - except for very minor changes in shadow length as the Sun rises 0.55 degrees per hour.]

133:46:16 Mitchell: Okay, Al, (garbled under Haise).

133:46:16 Haise: Roger, Al. And to rephrase the question earlier, on the way back down, you might integrate any distinction in the lithology on the way back with a better Sun angle and you're free to take grab samples en route to Weird.

133:46:35 Shepard: Okay.

133:46:36 Mitchell: Al, I think that's Weird to the north...I mean just to the left of (the line of sight to) North Triplet. And North Triplet appears to me to be right behind the LM (meaning 'aft of the LM').

133:46:48 Shepard: Yeah.

133:46:49 Mitchell: You agree?

133:46:51 Shepard: It's halfway between those two large boulders and one way down.

133:46:59 Mitchell: Yeah, I think that's right. Uh-huh, that's the one.

[The first part of the trip back to the LM is covered by the C1-to-C2 traverse map.]

133:47:47 Haise: Roger, Al. And do you have anything left on the 16-millimeter or has it been running on the MET.

133:47:57 Shepard: No, it hasn't. We might turn it on now and follow the progress.

133:48:00 Haise: Roger, Al. (Pause)

133:48:10 Shepard: Is it running now? (Pause) Yeah.

133:48:15 Mitchell: Have you checked the setting on it?

133:48:18 Shepard: Guess I better.

133:48:22 Haise: And, Al. Without taking any extra time, if you come across any boulders large enough, we might fill the comm check (square) on the way down. If you haven't already done that on the way up.

[Mitchell - "That was to get behind the boulder and see if we could block out the comm. But, by this time, we're down out of that big boulder field and there's nothing to squat behind and check the communications."]

133:48:49 Shepard: Let's go on. Are you on the thing back there?

133:48:52 Mitchell: No.

133:48:53 Shepard: Okay.

133:48:54 Mitchell: Want me to hold you back?

133:48:55 Shepard: No, that's all right.

133:49:01 Mitchell: Let me grab it, you're going to go over here in a minute. (Long Pause) (Garbled) I can't get you. Okay. (Long Pause)

[Jones - "I certainly don't hear the labored breathing on this run downhill."]

[Mitchell - "The run downhill was a piece of cake. It was easy to go downhill, and the MET was the only thing that really slowed us down, because it couldn't go as fast as we could go. It was bouncing around. And, having to navigate around craters and rocks and boulders, it was flipping/flopping all around. That was really the only thing that slowed us down. We could have been at a dead run and it's almost no effort."]

[Jones - "Do you remember feeling any instability, or was it a real stable run?"]

[Mitchell - "That nice skipping gait that I liked was very easy to do going down the hill. You could take longer steps, because of that bound and, with the slope, I'd float further down before I hit again. So, it was easy coming down the hill."]

[Shepard, from the 1971 Technical Debrief - "With respect to familiarization with the terrain: if we were coming at a relatively high rate of speed, as we were coming back down from Cone Crater - where we were kind of running in a down-Sun direction, there were times when we had to be careful. If you were running directly down-Sun, there's an area where (in) two or three more steps you're going to be in a crater. So, you're going to have to zigzag a little bit, but I didn't have any problems avoiding those things. As long as you can see two or three steps ahead of you, it's sort of like broken-field running. The whole process is so totally much slower than you are used to on the Earth (because of the lower gravity). Even when you get going in leaps and long strides, you can change direction and get around the craters fairly well. You can do this even with a fairly high-speed lope."]

[In American-Canadian football, the term "broken-field running" refers to a ball carrier making sudden changes in direction to avoid being tackled.]

133:50:15 Haise: Roger, Al. (Pause)

133:50:23 Shepard: Okay. Why don't we stop here to see if we're really going to Weird.

133:50:30 Mitchell: Yup. (Pause) Man, the LM doesn't seem like it's getting much closer.

[They have stopped near the top of 'Flank Ridge' to get their bearings. The approximate location of this stop is shown in the segment diagram.]

133:50:37 Mitchell: Huh? No, Weird is...Let's see; Weird is almost due east of the LM.

133:50:48 Haise: And, Al and Ed,...

133:50:49 Mitchell: (Garbled under Haise)...

133:50:49 Haise: ...we'd like an EMU check.

133:50:53 Mitchell: ...it's subdued.

133:50:56 Shepard: Okay; this is Al. 3.75 and 45 percent; and I'm on Min(imum)... (correcting himself) Medium flow, and I'm comfortable.

133:51:06 Mitchell: Okay, this is Ed. I'm on 3.75; Min flow, 40 percent, and very comfortable. And there is Weird, Al. You can see the triple crater in it.

[By 'triple crater', Ed means that he can see the distinctive shape caused by the fact that Weird actually represents three overlapping craters. See, also, the traverse map that Ed is carrying.]

133:51:18 Mitchell: It's got the white spot.

133:51:19 Shepard: Rog.

133:51:20 Mitchell: Got it?

133:51:21 Shepard: Yep. With the boulder in the near foreground.

133:51:23 Mitchell: Yup. (Long Pause as they start moving again)

[The boulder in question is undoubtedly the one just east of Weird Crater. It is labeled 1204 on the USGS map. This is Weird Rock, as shown in a three-photo portrait (assembly by David Harland) that Al will take at about 134:04:53. See, also, a detail ( 0.4 Mb ) from the November 2009, 0.5 m/pixel LROC image.]

[Jones - "I remember from reading in the technical debrief that you used the boulder next to Weird as a tracking point."]

[Mitchell - "Yeah. Because, as I recall now...The reason it got called Weird is because of the triple (garbled under Ed's rambunctious young son, Adam) inside of it. The triplet inside of Weird was, I think, what gave it the name. And it (the boulder) was a good landmark for me to see it. So, once we were sure we could see that, and coming downhill, we lost Weird again when we came down through this valley and I think we come on to that pretty quick."]

[Shepard, from the 1971 Technical Debrief - "We started back down the hill. From the elevation where we stopped, the view down in the valley was just fantastic. But, outside of that, we could see exactly where we were going at this time. We said we were going back to Weird and we could see Weird. There was no question about it."]

[Mitchell, from the 1971 Technical Debrief - "It was just like a map. Fortunately, there was a boulder between us and Weird. We used it as a reference; and, if that baby hadn't been there, I'm not sure we would have found Weird when we got down on the flat."]

[Shepard, from the 1971 Technical Debrief - "It wasn't there. That's another remark about navigation."]

133:51:44 Haise: Roger, Al.

[As indicated on the USGS map, they are slightly east of the top of 'Flank Ridge' and will continue running along parallel to the ridge crest as it slopes down toward the southwest. As indicated by the contour lines on the USGS map, the ridge top is fairly flat in this area.]

133:51:54 Mitchell: All right.

133:51:57 Shepard: We're just going to get a quick grab here of a rock, and I'll photograph it because it's got some tremendous fillets on it.

133:52:05 Mitchell: (Garbled) (Pause)

133:52:12 Shepard: Don't hit the fillets until I photograph it. (Garbled) and let me get a quick shot there. Get a quick pan across there. (Pause) That looks like...Yeah, we ought to get a piece of that baby.

[They are at Station C2, near CW.6/86.1 (0.8 Mb). See the C1-to-C2 traverse map. They are about 30 meters west of Station B3. They left Saddle Rock at about 133:46:13 and made a one-minute map stop along the way. They traveled about 195 meters and were on the move for 4 minutes 44 seconds. The average speed was 41 meters/minute.]

[Al's photographs of Filleted Rock and its fillet are AS14-64- 9130 to 9133.]

133:52:44 Shepard: Yeah. (Pause) Okay, here's a piece of it. (Pause) (Garbled)

133:52:57 Mitchell: (Garbled) them back here.

133:52:59 Shepard: (Garbled) crystals, don't lose it.

[This is sample 14053 which is a 251-gram piece of basalt. If lava cools rapidly, the resultant basalt will be very fine grained, with individual crystals too small to be noticeable. If cooling is slower, larger crystals can form and that is probably what Al is seeing.]

133:53:15 Mitchell: Hold it a minute. Hold it! Let me get a bag.

133:53:17 Shepard: Okay.

133:53:18 Mitchell: This darn bag dispenser is not doing what it's supposed to do.

[Mitchell, from the 1971 Technical Debrief - "We had a lot of trouble with sample bags. We threw a lot of them away because the little metal flags that were supposed to help you roll them up were getting entangled with each other. It was almost impossible to sort them out and pull one bag out of the dispenser. Generally, we pulled out two or three and one or two of those would get lost. It was too much effort to bend down and pick them up. It didn't look like we were going to use all of them anyway. That particular piece of equipment is going to have to be smoothed out. It was time consuming and hard to use."]

[Mitchell, from the 1971 Technical Debrief - "A couple of things on weigh bags, sample bags, and storage. It appears to me the geologists are now wanting larger and larger rocks. Rocks of any decent size at all are too big for the sample bags, and to have to search around for rocks small enough to go into the sample bag is an unnecessary time constraint. Either there are plenty of small-size rocks, or there are not. In our case, most of the interesting rocks were too large for the sample bag, and thus didn't get put into one."]

[One possibility is that Al is suggesting that they put the sample in one bag and, because they won't be able to close that bag completely, they put a second bag over the the top of the first bag as a hood or cap.]

133:53:33 Haise: Roger, Ed. 14-N....

133:53:34 Mitchell: (Garbled) filleted rock. Large filleted rock that Al photographed. Okay, let's go on. Do you want me to pull awhile?

133:53:42 Shepard: No, just watch everything. We don't want anything to drop off.

133:53:47 Mitchell: And you want me to hold back a while?

133:53:49 Shepard: No, no, let's just let it run. (Pause) Long as we don't lose anything.

133:53:55 Mitchell: Well, it's holding in very well. (Pause) (If it) doesn't turn over.

133:54:03 Shepard: A little higher c.g. (center of gravity) now than we had before with that big rock in there. (Long Pause) Fredo, can you give us an idea at about what time we should arrive at Weird?

133:54:24 Haise: Stand by one.

133:54:25 Shepard: (Garbled) time. (Long Pause)

133:54:53 Mitchell: That 16-millimeter (camera) is bouncing all over every place.

133:54:58 Shepard: Well, it'll be a good...

133:54:59 Mitchell: It's taken photos from every view. (Pause)

[They are saying that, if the camera were running while it was bouncing around, sooner or later it would capture the view in every direction.]

133:55:28 Mitchell: Yeah. Let's...Hey, here's a whole batch of them right down here, Al. Let's grab those.

133:55:34 Shepard: Which way, left or right?

133:55:35 Mitchell: Off to the left and ahead. Around that little crater. They're all from this same area.

133:55:42 Shepard: Houston. Unable to see any stratigraphy in any of these craters. The slumping has been such that it's pretty much destroyed. (Pause)

133:55:56 Mitchell: I'll grab this one right here.

133:55:58 Shepard: May be evidence of...

133:56:00 Haise: Roger, Al. And, positionwise, you're past Flank now. Is that correct? Or at least abeam position of Flank?

133:56:15 Shepard: No, we're not, Fredo. No, we're not at Flank yet. I'd say we're probably 15 minutes away from Weird. Did you get it on board?

133:56:27 Mitchell: As a matter of fact, I think this is Flank right here.

[At about 133:55:56, they stopped to make a grab sample. During the trip from C2, they were on the move for 2 minutes and 9 seconds. In the C2-to-D traverse map, the tracks they made are visible in a detail from LROC image M127049821 (lower left) and are approximated by the jagged track drawn on LROC image M114064206 (upper left). The distance traveled is about 132 meters and their average speed was 61 meters/minute. They are near the east rim of Flank Crater, about 40 meters above the label 'DgÕ and near boulder USGS 1014 on the USGS map.]

133:56:32 Mitchell: Yeah, I've got the rock on board.

133:56:33 Shepard: Okay, let's press.

[This is sample 14311, a 3.2 kg breccia which broke into four pieces prior to its arrival in Houston. A 115-gram fragment (14311,63) has become a NASA display sample and was photographed by Kipp Teague while it was on exhibit at Lynchburg College, Lynchburg, Virginia on 28 October 2000.]

133:56:50 Shepard: Okay. Now, we did not see that until we started approaching the edge of the boulder field. There's no evidence of that at all that we noticed.

133:57:01 Mitchell: Not down this far. One thing I did notice further outside of where we saw the white underneath; it looked like an impact had either been of the white rock or it was a splatter of white. And it was just outside where Al was reporting that the underlying layer was white. As a matter of fact...No, that's just...The Sun angle was causing it. Right now, some of the spray that we're kicking up looks white underneath, but I'm convinced it's just the (Sun) angle. I looked back the other way, and it's not substantiated.

133:57:45 Haise: Roger, Ed. (Long Pause)

RealVideo Clip (8 min 46 sec)

[Note that, until Al and Ed get back to the LM, the TV picture shows an unchanging scene - except for very minor changes in shadow length as the Sun rises 0.5 degrees per hour.]

[The MET almost overturns.]

133:58:55 Haise: Very good, Al. Looks kind of like you're making a little better time going down than up.

133:59:05 Mitchell: Yeah, the slope's a different way, Fredo. (Pause) In this case, the MET helps.

133:59:22 Shepard: Okay, don't let me lose that baby (meaning Weird Crater). That's it right there with the three...

133:59:24 Mitchell: Yeah.

133:59:25 Shepard: ...with the three rocks beyond it.

133:59:26 Mitchell: Yup.

133:59:29 Shepard: We're getting down to the place where we won't be able to see it. (Pause) This is probably Flank right here, isn't it?

133:59:48 Mitchell: I'm not going to say until I get down and look at the exact pattern. It probably is, Al. But if this is really Flank, we should have been at the top of Cone Crater where we were.

134:00:01 Shepard: Yeah, I know.

[Since leaving the site of the grab sample, they have been on the move for about 3 minutes 30 seconds and have traveled about 290 m at about 83 meters/minute. See the D-to-E traverse map. They are about 35 meters north of the crater labeled '915' on the USGS map segment at the lower right on the D-E map.]

134:00:12 Haise: Okay. It maybe looks down here, Ed, that may be what you're looking at there, if you've got another Flank-size crater, is the one by (Station) E.

[Fred is refering to the crater at CS.3/78.4 ( 0.6 Mb ) on the pre-flight geology map. This is the crater they confused with Flank during the outbound trek. The nearest rim of this crater is about 60 meters west of the planned Station E location. Initially, Ed seems to think that Fred is talking about the much smaller crater that is immediately WNW of the planned Station E location. This small crater is labeled '915' on the post-flight USGS map. Ed soon realizes that he and Fred are both talking about the crater at CS.3/78.4. See, also, the D-to-E traverse map.]

134:00:42 Haise: Okay, that looks like it may be the one by E.

MP3 Audio Clip by Ken Glover (6 min 16 sec)

134:00:43 Mitchell: ...20, 30 feet across. (Listens) Yeah, I think that's it, Fredo. And it's...Oh, it's at least 50 or 60 feet deep. (Pause)

[At 134:00:24, Ed began by describing the large crater centered at CS.3/78.4 ( 0.6 Mb ). On the map, the grid squares are 50 meters across and, as Ed says, the crater diameter is about 40-50 meters. He then mentioned a small, sharp crater on the south edge of the large crater with a diameter of 20-30 feet (6-9 meters). On the map, we see that this crater is centered at about CR.8/78.4 and is roughly 7 meters (23 feet) in diameter. Because even fresh craters have depths no more than 20 to 25 percent of their diameters, Ed's depth estimate of "50 or 60 feet (15-18 meters)" necessarily refers to the large crater.]

134:01:04 Mitchell: Okay. (Long Pause)

[This is Station E, near CR.9/78.7 (0.6 Mb). As Al mentions in a moment, they are on, or near, the rim of the 40-50-meter crater, as indicated on USGS map. From Station D to Station E they traveled about 375 meters and covered the distance in about 4 minutes and 30 seconds. This implies an average speed of about 83 meters/minute. See, also, the D-to-E traverse map.]

[Mitchell, from the 1971 Technical Debrief - "Even though there was a little confusion (in the navigation), we were able to spot ourselves coming by Flank, and then Fredo helped us to identify the one by point E. We knew where we were at that point but, after we passed point E and started looking for Weird, it just wasn't there."]

[Shepard, from the 1971 Technical Debrief - "But the boulder was, so we had a good landmark. That may be the way you'd do it."]

134:01:29 Mitchell: Yeah, it's falling apart as you pick it up; very crumbly, isn't it?

134:01:32 Shepard: Okay. You got a bag ready?

134:01:33 Mitchell: Yeah.

134:01:35 Shepard: Very, very soft rock from the rim of that crater, plus another one fairly close to it with crystal in it, that's flashing now; going into bag...

134:01:46 Mitchell: 15-N.

134:01:47 Shepard: Okay.

[This "very, very soft" rock is a regolith breccia, a clump of soil consolidated in an impact. Regolith breccias are also known as "instant rock". They put two pieces of the rock in bag 15-N but, by the time the bag was opened at the Lunar Receiving Lab in Houston, it contained "seven fragments with a lot of ÔresidueÕ"]

134:01:56 Shepard: (Garbled).

134:01:57 Mitchell: Not quite; let me get it in there.

134:02:02 Shepard: Stay behind me; we don't want to lose anything now.

134:02:04 Mitchell: Okay.

[They are leaving Station E and are headed toward Station F. As indicated on the E-to-F traverse map, Al will make a brief detour to Weird Rock.]

134:02:07 Mitchell: Yeah, we're going right for Weird. Head right for the big boulder. Then Weird's right beyond it.

134:02:12 Shepard: All right. (Long Pause) (To himself) Easy!

134:02:34 Mitchell: Okay, keep going. (Long Pause) (To Houston) This is Ed. I'm going back to Medium cooling.

134:02:54 Haise: Roger, Ed. (Long Pause)

134:03:07 Mitchell: One of the problems of going down hill here is that you have essentially diffraction, I guess, around your body, and it creates a halo effect in your shadow, and you just can't see a darn thing right in front of you.

[Jones - "Is there an example of the halo effect in one of the pictures?"]

[Mitchell - "Yeah, I think you can almost see it in the pictures. Most shadows are absolutely black and white, but when you're looking down-Sun, it's like it blossoms, just like it blossoms on the TV. Around the image. When you're looking down-Sun, everything seems to blossom around the shadow, right out in front of you. Around your own shadow. It's like you're getting a diffraction pattern - a reflection - in some way. Like the light's bending. It gives you a screwy effect, it really screws up your vision."]

[Jones - "That plus the zero-phase reflections that tend to wash things out."]

134:03:32 Mitchell: It's either blacked out or washed out right immediately down-Sun of you. We're going predominantly down-Sun now. (Long Pause)

134:04:07 Shepard: Okay, Fred, we're still moving, and MET's about 3 minutes away now from Weird.

134:04:17 Haise: Roger, Al. (Pause)

134:04:23 Mitchell: The crater we are going by now - we're just to the north of it, Fredo - is an old subdued crater.

[They have been on the move for about 2 minutes 20 seconds since leaving Station E. The subdued crater is the one centered at CQ.3/75.2 (0.6 Mb). On the USGS map, this crater is east of the smaller crater labeled '1211' and immediately north of the one labeled '1212'. See, also, the E-to-F traverse map. They have covered about 195 meters since leaving Station E; and their average speed is now about 84 meters/minute or about 5 km/hr. This speed is comparable to those achieved by various J-mission crew members, albeit on flatter ground. Note that Al and Ed are now off of Cone Ridge.]

134:04:32 Shepard: If you want to run over behind that boulder over there, and I'll try and talk to you.

134:04:36 Mitchell: You're the one that has to get behind it and try to talk to Houston.

134:04:38 Shepard: Oh, that's right.

[The two PLSSs are not identical. The comm unit in Ed's PLSS only 'talks' to the comm unit in Al's PLSS and not directly to the LM. Al's PLSS is the one that 'talks' to the LM and, thereby, acts as a relay station for Ed's comm. In order to see if a large boulder affects comm to the LM, it is Al who has to put the boulder between himself and the LM.]

[The track Al made running to the boulder can be seen - albeit faintly - in a detail ( 0.3 Mb ) from the November 2009, 0.5 m/pixel LROC image.]

[This brief experiment may be a relic of a much more elaborate set of lunar surface communications experiment proposed for Apollo 13 by BellComm researcher I.I Rosenblum in a 5 October 1970 memo ( 3.6Mb ) downloaded from the NASA Technical Reports Server in November 2008.

134:04:41 Shepard: Okay. (Pause) On second thought, maybe it's not big enough. (Garbled)...

134:04:51 Mitchell: No, don't think it is.

134:04:53 Shepard: No, I guess not. Sure is a big old boulder! I'll take a picture of it anyway. (Pause)

[This is Weird Rock, labeled '1204' on the USGS map. See, also, the E-to-F traverse map.]

[Al's photos are AS14-64- 9134 to 9136. David Harland has combined them as a mini-pan.]

[Weird Rock is visible on the traverse map at CR.0/74.3 ( 0.6 Mb ) and, also, in AS14-64- 9146, a frame in the pan that Al will take at Station F. Note that, in Al's Station F pan, which he takes at 134:07:18, the MET tracks do not go near the boulder, confirming that it was Al who took the boulder photos.]

[With regard to the possibility of losing comm if they don't have line-of-sight to the LM, Journal Contributor Bill Wood writes, "While one would think that a VHF signal in the range the PLSS transmitters used (roughly 250 to 300 MHz) should be only line of sight, the signals can bounce and bend around the surface of the Moon up to a point. Especially with the 1 -2 watt power the PLSS transmitters used. I suspect they could go a few kilometers over the horizon and still communicate just fine. If they could keep a direct line of sight they could probably go as far as 500 km or so and still be heard."]

[In a second e-mail, Bill added, "Each time the CSM would go around to the far side of the Moon, the S-band downlink signal (2200 Mhz) would actually be present for a short time after it went behind the moon. It has a very distinctive signature that one could hear if the receiver operator had the dynamic phase error (DPE) signal on a speaker. Tom Jonas, our shift Receiver-exciter engineer occasionally reported seeing the CSM downlink on the USB receiver spectrum display unit popping in and out just before the CSM would come out from behind the Moon. So it looks like even S-band signals get refracted on the surface of the Moon."]

134:05:23 Shepard: Oh, probably a couple of hundred meters short of Weird. (Long Pause)

134:05:42 Mitchell: This country is so rolling and undulating, Fred, with rises and dips everywhere, that you can be going by a fairly good-size crater and not even recognize it.

134:05:57 Haise: Roger.

134:06:00 Shepard: (To Ed) Okay, I'm back with you.

[The tracks Al made as he ran to rejoin Ed are not obvious in the detail ( 0.3 Mb ) from the November 2009 LROC image.]

[The youngest component of the Weird group is the sharp, raised-rim crater at CR.2/72.9 (0.6 Mb), which is labeled '1202' on the USGS map.]

134:06:39 Mitchell: Okay.

[They are at Station F, near CQ.0/73.5 (0.6 Mb). See, also, the E-to-F traverse map.]