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148:55:58 Irwin: Got it?
148:55:59 Scott: Yup. (Pause)
[Evidently, Fendell has some control over the iris because the scene brightens and, although the image of the flag saturates, Jim comes into view as he goes of-camera to the left to changes places with Dave.]148:56:08 Irwin: Okay.
148:56:09 Scott: Get it?
148:56:10 Irwin: Got it. (Pause)
[Jim has just gotten the camera from Dave. Just before Dave comes into view and gets into position east of the flag, the TV images darkens.]148:56:23 Allen: And, Jim, you'll get a feedwater tone in about a minute. Just wanted to warn you, and we're coming up on twenty minutes remaining, two-zero.
148:56:32 Irwin: (Responding to Joe) Okay. (To Dave) Oh, that is a good picture.
148:56:35 Scott: Isn't that a neat picture?
148:56:38 Irwin: Get little...(Pause)
148:56:42 Scott: (Garbled)
148:56:43 Irwin: Try another setting. How about an f/8?
148:56:45 Scott: Yeah, try f/8.
148:56:47 Irwin: Leave it at...
148:56:48 Scott: Yeah.
148:56:49 Irwin: ...f/11, there.
148:56:50 Scott: Yeah. That's what it called for in the...
148:56:51 Irwin: Yeah. (Pause) Okay, I'm taking you again, boss.
148:56:56 Scott: Okay.
[The TV image brightens as Dave salutes.]148:56:58 Irwin: Oh, you look colorful.
148:56:59 Scott: How about that? Even with the dirt, huh? (Pause)
148:57:05 Irwin: Okay.
[Dave hops off camera to the left.][Jim took four pictures of Dave, AS15-92- 12448 to 12451. Frame 12451 is the best of these. Note the footprints and Rover tracks in the crater to Dave's right. This is the last surface picture on magazine 92. The remainder of the magazine was used in orbit.]148:57:07 Scott: You like that flag there, Joe?
148:57:10 Allen: It's beautiful.
148:57:15 Scott: Yeah. We think it's pretty nice, too. (Long Pause)
[Dave crosses in front of the TV, headed for the LM.][Note the slight motion of the lower righthand corner of the flag after Dave passes. Journal Contributors have suggested a number of possible causes: (1) Dave could have brushed against the flag with his left arm as he went by; (2) he could have kicked some dirt with his boot that hit the bottom of the flag; (3) he could have pushed a mound of soil sideways with his boot that pushed against the flagstaff ; (4) the impact of his boots on the ground as he ran past could have shaken the flagstaff; (5) he might have been carrying a static charge which attracted the flag material; (6) the flag could have been disturbed by emissions from the backpack.]
[In thinking about these possibilities, numbers 5 and 6 are very unlikely, since there is no evidence of similar flag motions during the Apollo 14, 16, and 17 deployments for which we have good video or - in the case of Apollo 14 - film coverage. With regard to foot impacts, we can certainly see the ground move when flagstaffs and cores are hammered into the ground, but the motions extend only a few centimeters outward and, because the Apollo 14 flag points at the LRV TV camera, Dave problably doesn't get close enough to the flagstaff for his footfalls to have any noticeable effect. Similarly, it doesn't seem likely that he got close enough to the flagstaff to have moved it with a displaced mound of dirt.]
[The possibility that Dave kicked some dirt high enough to hit the bottom of the flag is not out of the realm of possibility, although in the many cases were we have good TV coverage of sprays of dirt flying out ahead of running astronauts, most of the particles have relatively flat trajectories and land after traveling a meter or so. Indeed, Buzz Aldrin did some purposeful test kicks to see what happened and how the sprays looked under various lighting conditions. This is discussed after
110:18:31. Buzz comments, "Houston, it's very interesting to note that when I kick my foot (garbled) material, with no atmosphere here, and this gravity (garbled) they seem to leave, and most of them have about the same angle of departure and velocity. From where I stand, a large portion of them will impact at a certain distance out. Several (garbled) percentage is, of course, that will impact (garbled) different regions out (garbled) it's highly dependent upon (garbled) the initial trajectory upwards (garbled) determine where the majority of the particles come down, (garbled) terrain."]
[My impression is that few, if any, particles go above knee height.]
[A likely explanation is that Dave brushed the flag with his arm as he went running past. As can be seen in the TV, he is carrying the Hasselblad camera that he just got from Jim and it looks as though, if he brushed the flag at all, he did so with his left elbow. To check this possibility, I have compared three views of the scene: (1) Jim's fourth tourist picture of Dave, AS15-92-
12451; (2) the TV view of Dave while Jim was taking that picture; and (3) the TV view of Dave as he went past the flag after the picture taking was complete. The results are summarized in a
labeled detail from 12451.]
[Because the TV camera is not visible in 12451, I have estimated its location from Dave's fourth photo of Jim, AS15-92-
12447. Using that estimated camera location, the four green lines show the relative vertical locations of the top of the flag where is is tied to the flagstaff, the top of the main body of Dave's PLSS, the bottom of the flag where it is attached to the flagstaff, and the bottom of Dave's PLSS. Relative vertical locations can be measured as the intersections of the lines with any vertical plane such as the left edge of the image.]
[Although Fendell moves his aim to the right and then up by small amounts between the time Jim takes 12451 and the time Dave crosses between the camera and the flag, the relative locations and spacing of the top and bottom of the flag do not change and, conseuqently, these can be used to place the top and bottom of Dave's PLSS as seen in the TV image onto 12451. Because DAve stood with his PLSS erect while Jim was then taking his picture but then assumed a more normal posture by leaning forward about 10 degrees while he was running, I have adjusted the apparent locations of the top and bottom of the PLSS (red lines) so show where the PLSS would have been had it been perfectly vertical.]
Finally, I placed the PLSS (red rectangle) where it would have been in 12451 had Jim taken the picture at the moment Dave was running past the flag. There are two ways the PLSS can be placed. In the first, I measured the apparent height of Dave's PLSS as seen in 12451 and found the place the top and bottom red lines are that far apart. This marked the location of the side of the PLSS nearest to the TV camera. The rest of the PLSS outline was then drawn to scale. Alternatively, we note that, in the TV record, the apparent long dimension of Dave's PLSS - measured along a line titled 10 degrees to vertical - when he ran past the flag was 2.4 times the apparent long dimension of his PLSS when JIm was taking 12451. This means that the near face of the PLSS at the former time is 2.4 times as far from the TV as it was at the latter time. This would put the PLSS a bit closer to the TV camera than I have placed it in the
labeled detail.]
[The result is not clear-cut. The estimated PLSS locations makes it possible that Dave's elbow could have touched the flag; but just barely, if at all. This may be consistent with the low amplitude of the observed motion, in that the low amplitude suggests only a slight perturbation, as might have happen if Dave barely brushed the flag with his elbow.]148:57:40 Irwin: (To Houston) Can we get in now?
148:57:44 Allen: Jim, you're coming up on feedwater tone, probably.
148:57:45 Irwin: What else have you got for us, Joe? (No answer) (Pause)
148:57:55 Scott: (To himself) Okay.
148:57:57 Irwin: That was good timing, Joe. I've got it.
[Fendell pans right, looking for Dave and Jim at the LM.]148:58:00 Irwin: Dave will you put me on...
148:58:01 Scott: Yeah.