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Getting Low, Grabbing, Kneeling, Falling, Getting Up

Copyright 2008 by the Editors of Working on the Moon.
Last revised 8 June 2008.

1. Summary

The Apollo 11, 12, and 14 crews avoided contact with the ground for four reasons:

(1) Considerable effort was made during Apollo to protect surface equipment from excessive solar heating.  The silver surface of the Hasselblad cameras used outside the LM is an example.  Although the combination of the multi-layered suit and the cooling system in the PLSS was designed to handle any likely heating loads with plenty of margin to spare, dust on the suits could, in principle, increase the rate of solar heating and, therefore, the use rate of cooling water by the PLSS sublimator.  However, experience showed that cooling water use rates were well within the expected range and that any increase due to dust on the suits was masked by variations in use from times of light workloads to times of high workloads.

(2) Prior to Apollo 11, the suit had not been cleared (approved) for kneeling.  During the post-flight Technical Debriefing, Neil Armstrong said, ""In general, there were a lot of times that I wanted to get down closer to the surface for one reason or another.  I wanted to get my hand down to the surface to pick up something.  This was one thing that restricted us more than we'd like.  We really didn't have complete clearance to go put our knees on the surface any time we wanted.  We thought the suit was qualified to do that in an emergency, but it wasn't planned as a normal operation."

(3) Despite the care taken by the Apollo 11 crew, they brought a great deal of dust into the cabin, some from use of the Lunar Equipment Conveyor (LEC), some on the lower parts on the suits, and some on bags and other containers brought up from the surface. Both crewmen got quite a bit of dust on their skin while doffing gloves and helmets.  Use of a vacuum brush and of the Environmental Control System (ECS) oxygen hoses to get dust off the suits and other surfaces eventually resulted in most of the dust being captured in the ECS Lithium Hydroxide canisters filters.  Floating dust was not a major problem when they returned to weightless conditions in lunar orbit. They did wear their helmets during the ascent to prevent any dust particles from getting in their eyes, particuarly after their return to weightlessness.  The Apollo 12 crew spent about three times longer on the lunar surface than did the Apollo 11 crew and, despite continued efforts to avoid getting the suits dirty and to clean some of the dust off the suits before climbing the ladder at the end of each EVA, the amount of dust was too great for the ECS filters to handle.  The amount of dust, particularly after they returned to lunar orbit, was both an annoyance and a possible threat to eyes and lungs. (See Section 6.2 of the Apollo 12 Mission Report for a discussion.)  Later crews used a large dust brush for cleaning the suits before climbing the ladder at the end of each EVA and also stomped their feet once on the ladder to shake off more dust.  They also had a vacuum cleaner for use in the LM cabin and a filter on the ECS Cabin Fan to capture more of the dust.  Finally,  from Apollo 15 onward, the crews stepped into jettison bags once they were back in the cabin in an attempt to isolate the suit legs.  These measures reduced the amount of dust in the cabin to levels acceptable in the context of Apollo.

(4) The A7L suits worn by the A11-14 LM crews had convolutes at the ankles, knees shoulders, elbows, and wrists so that those joints could be used with some ease.  However, the suits did not have a convolute at the waist, so that bending the waist was difficult.  During the 1991 Apollo 12 mission review done for the ALSJ, Pete Conrad was asked if he could have knelt to retrieve a dropped color chart and replied. said, "I can't bend over, so it doesn't do me any good to kneel.  If I kneel, I'm not getting any closer (to the ground)...Well, I'm getting closer, but I can't bend over and, (with my back vertical), I can't get my arms down past my knees, so it's still not doing me any good."



As Neil Armstrong commented during the post-flight, Apollo 11 Technical Debriefing, being able to pick things up or to work with them close to the ground  would have made the work a lot easier: "We didn't let ourselves settle on our knees a lot of the times to get our hand on the surface.  Now I think that is one thing that should be done more on future flights.  We should clear that suit so that you could go down to your knees, and we should work more on being able to do things on the surface with your hands.

On Apollo 11, Neil was on the surface for only about 2 hours 12 minutes and Buzz for only about 1 hour 42 minutes.  As was appropriate for this first mission, their work load was far less ambitious than that of the later crews but, still there were times when it simply made sense for them to reach down, usually using the spacecraft for support and, on one occasion, Neil can be seen bobbing down to one knee to grab something off the ground, probably the close-up stereo camera.

After Neil and Buzz demonstrated that there were no fundamental problems in doing useful work, NASA went ahead with plans for the follow-on crews to do two four-hour EVAs and, later, three seven-hour EVAs

The A15 crew started out trying to keep clean, but found that they were going to get dirty no matter what they did.  Rocks too big for the tongs had to be picked up.  Dropped pieces of equipment had to be retrieved.

Falls were inevitable. In the interest of making best use of their time, the Apollo 15 crew became more casual about kneeling and falling, except when working on slopes.  The A16 and A17 crews threw themselves into the work except on the steepest slopes or when working around rocks big enough to be hazardous.

Because control of dust is going to be a far more important consideration in long-duration lunar stays than it was during the brief Apollo visits, on-going assessments should be made of the relative merits of - and emphasis on - (1) limiting dust accumulation on the suits through the use of canes, grabbing tools, etc., (2) suit cleaning prior to re-entry into shirtsleeve environments, and (3) use of dust locks for stowage, maintainance, and repair of suits and other outdoor equipment. Procedures and equipment will undoubtedly be modified as further experience is gained.

2. Lessons

Much of what was learned during Apollo relative to the topics discussed on this page apply specifically to the Apollo suit and particularly to the A7LB suits worn by the Apollo 15, 16, and A17 crews.

Important characteristics of the suit.  Using the suit.  Using 1/6th-g.  Learning from the experience of prior crews.  Training in the 1/6th-g airplane.

Falling on the moon is usually not dangerous because (1) the moon's weak gravity gives the astronaut time to react; (2) the weak gravity field means that the astronaut's impact velocity is much lower than it would be on Earth; (3) excepting sizeable rocks - which are not common except near the rims of large, fresh craters -  the ground is soft; (4) because the Apollo astronauts worked relatively near each other, if either of them fell in an awkward position, his crewmate could help him get up; and (5) the multi-layered, soft suit was forgiving.  There were no instances during Apollo of astronauts falling on rocks big enough to be a hazard.

There were no known falls on Apollo 11; two probable falls on Apollo 12, and none on Apollo 14.  There were four known or possible falls on Apollo 15, one of them fairly spectacular.  There were twelve falls on Apollo 16, one of them potentially dangerous.  And there were 9 falls on Apollo 17, two of them spectacular.

No injuries resulted from any of the falls - excepting a wound to Charlie Duke's pride - and there was no equipment damage nor any increased suit leakage.  Suits and, sometimes, camera lenses got dirty.  The astronauts had lens brushes when needed.


3. Getting Low and Grabbing


The LM crews had scoops and tongs for use in picking up small rocks.  The tongs, in particular, could also be used for  grabbing dropped sample bags and other small, dropped objects.  If, however, a rock or dropped object was too large for the scoops or tongs, one method of picking something up off the ground was so bend a knee enough that the astronaut could get the object in his hand and then rise without having touched a knee to the ground.  If the Rover, part of the LM, or a long-enough tool - such as the Universal Handling Tool (UHT), a scoop, or a geology rake - was available it could be used as a support or prop.  Taking the support in one hand, he could put his opposite leg out to the side, bend that knee, and get low enough for a grab.  Rising with the help of the support was relatively easy.  If no support was available, it was possible to do a dynamic grab, bobbing down with one knee and making the grab before  the internal pressure of the suit started to straighten the bent knee.  With practice, some of the astronauts got fairly good at doing dynamic grabs, particularly John Young who, prior to Apollo 16, had gained some proficiency in the 1/6th-g airplane.  Even Young sometimes had to make more than one attempt at a grab.  Loss of balance and falling was always a possibility.

The following table is not exhaustive.  The included examples generally have good TV coverage and demonstrate of variety of techniques used on the Moon - some more successfully than others.


Ground Elasped Time (hh:mm:ss)
Type or Circumstance
Notes

Apollo 11

Technical Debriefing
Need to get closer to the surface
Armstrong - "In general, there were a lot of times that I wanted to get down closer to the surface for one reason or another.  I wanted to get my hand down to the surface to pick up something.  This was one thing that restricted us more than we'd like.  We really didn't have complete clearance to go put our knees on the surface any time we wanted.  We thought the suit was qualified to do that in an emergency, but it wasn't planned as a normal operation."  Extended discussion of kneeling.
109:44:57
Using the ladder for support
While holding onto the ladder with his right hand, Buzz tries reaching down to his left, probably bending his knees.  "Reaching down is fairly easy. "
110:52:57
Dynamic grab
Neil bobs down to one knee to grab something off the ground, possibly the close-up camera.  During the post-mission Technical Debriefing, Neil mentioned that had to pick it up off the surface on three separate occasions, bobbing down once and using tools the other two times.  "It's a major effort to get down to the surface to pick the thing up."  Discussion
111:23:29
Using the MESA for support
Buzz bends his knees and reaches forward to get the close-up camera.

Apollo 12

118:19:43
Leaning on a rock?
On the way back from Middle Crescent Crater, Pete and Al want to collect some samples that prove to be too big for the tongs. The dialog suggests that Al leans on a larger rock and has Pete push the desired samples into reach.  No TV.
133:44:09
Using a strap to get low
Al takes hold of a strap on the Surveyor parts bag Pete is wearing and provides support while Pete reaches down to grab a sample.  Although Pete and Al recommended this technique for use by later crews, it was never repeated.  No TV.

Apollo 14

113:52:26
Going to one knee
Shepard, from the Technical Debrief - "Balance was good and getting control was good.  I did not fall down at any time during either EVA.  I got down on my knee a couple of times to pick up some things, but I got right back up again.  Never, at any time, did I have any trouble with falling down and balance."
115:26:10
Using a LM strut for support
Al leans on the LM strut while he places the back-up, B&qmp;W TV in the east footpad.
115:27:47
Using tongs rather than kneeling
Ed drops the weigh bags and, rather than use the MESA for support, gets the tongs from Al. "It'd probably save getting any dirtier than necessary."
115:30:09
Flight suit not "broken in"
Mitchell, from the Technical Debrief - "Although my suit did exceptionally well, far better than the training suit ever did, it was still stiffer and took more effort to just hustle around than the training suit did, which was well broken in.  I encountered a little bit of a problem with bending over, which I had not encountered in one g, and I think this is in proportion to the forces between the one-sixth g and the stiffness of the suit compared with the well-worked-in suit in one g.  I found that I could not bend down to the MET level.  I could not just bring my body forward like I could in the training suit and get down to the MET.  I had to bend my knees or get down on a knee to reach things low on the MET, such as the weigh bags down on the side, or the camera retaining clips on the MET.  It was more difficult for me to bend down for them (than it had been in training)."  Al commented, "I don't know whether it was unique to Ed's suit or not, because I didn't have that problem."
116:50:38
Bobbing down to one knee
Ed goes briefly to one knee, perhaps putting the first geophone in the ground.










Apollo 15

120:52:24
Using the Rover support
Dave leans on the front of the Rover to lock the high-gain mast in place.
122:55:50
Using the scoop to lift an end of the dropped tongs into reach
Dave dropped his tongs earlier and, rather than try a dynamic grab or go to his knees, he has Jim lift one end of the tongs with the scoop.  With his knees bent, Dave gets low eough to grab the tongs.
122:56:48
Deeply bent knee with the other leg out to the side as a counterweight
Dave gets his left leg out to the side and then bends his right knee almost to 90 degrees to get a sample bag low enough for Jim to pour in some soil from the scoop.  At 122:57:06, Dave moves downhill till he is level with Jim and doesn't  have to bend his knees as much to get the sample bag in position.
124:43:20
Dynamic grab
Dave sticks his left leg behind him with his right knee flexed. He then bobs down till his left knee is almost to the ground and grabs the heat flow probe that was on the top of the HFE.
124:46:07
Using the UHT as a prop
Dave reaches down to remove  a dust cover from the heatflow package.  With the UHT in his left hand as a prop, he extends his right leg to the side, bends his right knee inward, and reaches down easily with his right hand.  Les effort than the dynamic grab he did without a prop three minutes earlier or the one he will do in about 25 minutes more.
125:11:04
Dynamic grab
Dave bobs to one knee to grab the heat flow probe, which is on the ground next to the emplacement hole.  His first attempt fails.  Fendell zooms in just in time to capture Dave's second, successful attempt.  As he comes up, he says, "I sure wish I had a UHT." Most likely, he is thinking that he could have hooked the UHT handle under the cable to lift it.
125:13:53
Dynamic grab
It takes Dave three attempts to get the probe bag off the ground.
125:23:15
Dynamic grab
Easy grab of the second heat flow probe.
144:23:00
Dynamic hammer blow
Dave wants to use the hammer to break open a 15-cm rock that is lying on a flat-surface.  He puts his right foot forward toward the rock, puts his left foot back, and flexes his knees, almost touching the ground with his right knee.  Once down, he breaks the rock with a single blow and then lets the internal suit pressure straighten his knees so he can stand.  A classic, elegant use of the suit.
148:27:01
Dynamic grab
Easy grab of the wire loop on the drill.  The loop was about 15 cm off the ground.  The drill stem was nearby at about chest height, but Dave didn't bother using it.

Apollo 16

119:24:37
Probable dynamic grab
John practiced doing dynamic grabs in the 1/6th-g airplane. Charlie comments,"Hey, you're doing pretty well with that deep-knee-bend stuff." John replies, Yeah, I already picked up a rock to see if it was possible."  No TV until they put the camera on the Rover.  Discussion.
120:17:48
Flexing the knees
To get something from the back of the MESA, Charlie  jumps far enough onto the MESA to balance on his stomach.  To get down, he bends his knees up 90 degrees, kicks them down, but doesn't come off.  A second later, he pushes himself off with his hands.  Discussion of the difficulty of keeping the knees bend against the internal pressure of the suit.
120:18:21
Kneeling using the MESA for support
Charlie has no trouble kneeling to pick up a piece of dropped equipment.
120:22:55 Failed dynamic grab
John has dropped the lower flagstaff section and attempts to make the grab.  He doesn't get low enough and decides to kneel while using the upper flagstaff section for support.
121:04:29
Dynamic grab
Charlie successfully grabs the drill-stem rack, which had tipped over.  Although the relatively large size of the rack made this grab relatively easy, Charlie is pleased with his success, "I'm getting where I can bend down in that suit, Tony."
121:11:53
Dynamic grab
Charlie successfully grabs the wrench off the drill stems on his second attempt. He does another successful grab at 121:15:13, jumping up slightly before he starts down so that the knee will bend more and he can get lower.
121:16:48
Using the drill for support
As he completes one of the heatflow holes, Charlie has to lean forward to maintain his grip on the drill and keep it from turning ("torquing") as gets close to full depth.  He looks very stable.
121:26:12
Leaning on drill to reach down
With his feet well back, Charlie leans forward on the drill with his left hand to attach the wrench to the stems.  To get up, Charlie keeps his weight on his left hand and moves his feet far enough toward the drill that he can stand easily.
121:52:04
Dynamic grab
Charlie grabs the rammer-jammer on his second try. In coming  back up, he springs completely off the ground.  He lands on both feet and then does a small hop to his left to get his balance.
121:53:10
Failed dynamic grab
Charlie misses the rock he was trying to grab and has to scramble to his left to avoid falling.
122:52:04
Dynamic grab
John grabs a dropped SCB.  He is partly obscured by the back of the Rover.
123:58:35
Stable bent knee posture to use the hammer
John sticks his left leg out to the side and then bends his right knee enough to use the hammer on a partially-buried rock.  He stays down for about 5 seconds while he strikes the rock twice.  After John stands up for a moment, Charlie offers to hold him down and, as John gets down again, Charlie puts his hand on John's left shoulder.  John pries a piece of the rock loose and then rises, only having stayed down for a second or two.  Note that John wasn't having to reach down quite as far as Dave Scott did when he used the hammer in the Station 6 crater at 144:23:00.
124:08:01 Collecting the biggest Apollo sample
As he had done three times wiile working on the far side of Plum Crater, Charlie puts the scoop out in front of him, holding onto it as his sinks to his knees.  "Big Muley" is roughly cylindrical in shape and is about 20 cm tall and 15 cm in diameter.  It's terrestrial weight in 11.7 kg (26 lbs) but only 2 kg (4.4 lbs) on the Moon.  It is the bulk more than the weight that makes collecting it a challenge.  Charlie rolls the rock toward his right leg and tries to get his fingers under it and roll it up onto his thigh.  That fails and he them leans forward far enough that he can wrap his fingers far enough down that he can press the rock firmly against his leg.  Still using the scoop as a support, he manages to stand.  He then release his grip on the scoop and moves his left hand down toward the rock.  He then does a little jump and the rock floats up enough that he can get a solid grip with both hands.  Excellent TV.
149:03:28
Dynamic grab
Classic example of John in action

Apollo 17

118:25:54
Balancing on toes while in a deep knee bend
Gene and Jack take tourist photos of each other with both the flag and Earth in view.  To do so, they bend their knees, almost kneeling and balancing on their toes.
119:35:45
Using the drill for support
Gene puts his right hand on the drill for stability, puts his left leg back, and flexes his right knee until his left is almost touching the ground.  He attaches the wrench to the drill stems and rises without difficulty.  Gene uses the technique again when he picks up the neutron probe at 121:09:29.
119:36:39
Dynamic grab
On what may be Gene's first attempt at a dynamic grab, he gets down and holds the position long enough to remove the wrench from the drill stems.  He will need some practice to become efficient.
119:39:53
Leaning on the drill without kneeling
To remove the wrench from the drill stems, Gene puts the drill down, bends his knees enough to get his right hand on the drill, moves his feet back a short way, bends his knees slightly and, with most of his weight on his hand, is able to remove the wrench.  He then steps forward and rises without difficulty.  He does something similar when attaching the wrench at 119:44:46 and removing it a short time later. "Oh, man, that works great!"
119:48:57
Knee bends
Gene does a series of quick knee bends so he can push the heatflow probe into the drill stems.  He doesn't use any support.
120:08:01
Dynamic grab
Gene knocks over the drill and, in part because one of the handles is sticking up, grabs it without trouble.
120:33:02
Kneel, dynamic grab, kneel, dynamic grab, kneel.  Difficulty  of working in a small crater.
In a somewhat frustrating and certainly tiring sequence,  Gene uses the drill for support so he can go to his knees to thread a drill stem into the one in the ground.  As he gets to his feet, he knocks the drill over and, after failing with one dynamic grab attempt, gets it with the second.  He rests for a moment and them uses the drill again to kneel while he tries to remove the wrench.  He is unable to free it and hops to his feet to have a rest.  After a few seconds, he tries to re-position the drill, but it falls over.  Once again, it takes him two tries to get low enough to grab the drill.  At the end of this sequence, he mentions that he has been working in a small crater and that working on the slopes was difficult.
120:51:30
Using the suit while removing the deep core with the jack
To get maximum throw of the jack handle, Gene does deep knee bends but, after a short while, he gets on his knees so he can push the jack handle all the way to the ground. He has his left hand on the core stems for stability.  Later, he rises up off his knees and then drops back down to put more force on the handle.  "It was a lot of hard work; and not at all easy."  After about 4 minutes of effort, Gene stands to rest, using the jack handle for support. Comments from Jack, twenty years later, on Gene ability to bend his knees "almost with his backside on his heels.  There's no way I could have done that; I just couldn't bend my suit that much."  During Jack effort with the jack starting at about 121:00:02, although he litterally throws his weight onto the handle, he gets very little knee bend at the bottom of each stroke.
120:55:55
Efficient use of the jack while kneeling
During Gene's second session with the jack, he is on his knees with his right hand on the core stems for stability.  As he pushes the handle down with his left hand, he leans to the left to push the handle all the way down, raising his right knee a few inches off the ground to get better leverage.  After nine strokes, he uses the core stem for support and he hops up onto his feet.  Gene is righthanded.
121:01:30
Controlled fall on the jack handle
After Jack's spectacular fall, he has more success with the jack by grasping the core stem with his right hand - Gene is also holding the stems, probably to minimize any lateral stress Jack might impart - and does a controlled fall, pushing the handle down with his extended left arm.  Gene has his left foot on the treadle to keep it steady.  After Jack does four strokes, they change places.  Gene goes to his knees and, as he did earlier, leans to his left as he pushes the jack handle all the way down.  After about six more strokes, working the handle becomes much easier.
122:19:01
Leaning on boulder
Jack leans on the Station 1 boulder while he breaks off a sample.
123:11:04
Gene supports Jack for deep knee bend
Jack has to unfold the SEP solar panels, which are at about knee height.  To avoid knocking the transmitter over, he gets Gene support so he can do a stable, deep knee bend.



140:52:26
Using the MESA for support
Gene bends his knees, using the MESA for support, to reach the gravimeter button.
143:29:11
Maintaining bent knee posture
Gene uses the hammer on the side of a knee-high boulder.  Discussion of adapting "to whatever the suit would give you."  A short while later, Jack flexes his knee enough that he can skim the sample off the surface with the scoop.
144:47:00
Bobbing to one knee on a slope
While working on the slope outside the rim of Ballet Crater, Jack faces cross-slope and bobs down to his upslope knee to retrieve the scoop.  "Facing up a slope like that, it was easy to get down and back up."
144:50:23
Difficulties on the slope at Ballet Crater
Jack has a sequence of mishaps, dropping things and trying to retrieve them. 
145:31:58
Deep knee bend for close-up photography
Gene bends his knees and gets up on his toes to take some close-ups.  He has a bit of trouble getting into a stable position.  "In one-sixth gravity you can go down slow enough and you can waver in that almost-kneeling position - uncomfortable and hard to sustain - long enough to get a couple of pictures at a 125th of a second."
166:22:32
Jack uses a boulder for support; Gene uses the hammer
Jack retrieves the scoop using the Station 7 boulder for support.  Separately, Gene uses the hammer as a support in the same way he used the drill earlier; he scoots his legs backwards as he leans on the hammer without going to his knees and tries to pick up a football-sized rock.  It is too big.  He goes to both knees and finally gets a good grip.  He uses the hammer to push himself far enough back that he can stand.

4. Kneeling

The following table is not exhaustive.  Most of the included incidents are ones with good TV coverage and/or relevant commentary.  For unknown reasons, John Young and Gene Cernan were able to kneel without needing a support to keep the internal pressure of the suit from straightening the knees and forcing them forward onto their hands.  With a long-handled tool  for support, the other astronauts who tried kneeling were able to do so.



Ground Elapsed Time (hhh:mm:ss) Subject or circumstance Notes

Apollo 11

109:44:57
Trying knee bends at the ladder
Buzz tries some knee bends.  It may be at this point that he gets the smudges of dirt on his knees can be seen in AS11-40-5903.
110:52:57
Bobbing Down on one knee
Neil bobs down briefly, apparently to grab something off the ground, probably the Apollo Close-up Stereo Camera.  See the extensive discussion of kneeling following 110:45:03.

Apollo 12

115:48:57
Low value of kneeling without a hip bellows
In a 1991 comment, Pete notes that kneeling was of less value the early missions because their suits did not have the hip bellows/convolute that allowed the J-mission astronauts sit on the Rover.  The lack of a hip convolute may have made cabin egress more  difficult on the early missions.
118:19:43
Avoid kneeling to keep clean
Pete and Al Bean went to some lengths to avoid kneeling, in hopes of keeping the suits relatively clean.
136:51:56
Ways to kneel
From the post-EVA-2 debriefing:

Gibson: Roger, Al.  Say, did either one of you kneel down
in order to get anything off the surface, or did you use the
newly-developed Bean technique of holding on to the Surveyor parts bag and
lowering the Commander to the surface?

Conrad: Yeah.  Well, we used all kinds of things like that.  You could take the shovel and stick it in the ground and just do a one-arm pushup and lean down and pick up a rock off the ground with the other hand. It's really a ridiculous way to do it.   If you had a suit that would bend, why, you'd have the whole program wired.  But, you could do that. It's okay.  I fell over once out there, and Al picked me back up again.  It's no big deal.

Bean: But, in the same sense, you're always fussing around trying to get down there to get these rocks, and we did kneel down a couple of times. I knelt down and picked some stuff up.  And it's particularly easy if you got that Hand Tool Carrier with you. But we really do need to come up with some sort of strap or something that would allow you to lean over and grab a rock that won't fit in those tongs.

Apollo 14

113:52:26
Tech. Debrief extract
In discussing mobility and stability, Al mentions "I got down on my knee a couple of times to pick up some things, but I got right back up again."  Emphasize the value of training in the 1/6th-g airplane.
115:30:09
Tech. Debrief extract Ed comments on the greater difficulty reaching low on the Moon.  Al says he didn't have any trouble. In the TV, he goes down almost to a kneeling position to attach a weigh bag to the MET.
116:17:29
Kneeling with torso vertical
When the astronauts were at the ALSEP deployment site, TV images of their suits were badly bloomed.  Nonetheless, we see one of them - possibly Ed - sink to his knees with his center-of-mass well back and then, after placing the SIDE subpallet on the ground, rising easily to his feet.  Ed may have used his Universal Handling Tool as a prop to help him keep the internal pressure of the suit from straightening his knees while he got down.  Similar episode at 116:36:53.
116:50:38
Bobbing down onto one knee
Ed pushes a geophone into the ground.
131:24:16
Using the MET for support
Ed uses the MET for support so he can kneel and grab a dropped map.
132:42:43
Drop to one knee
During the climb to Cone, Ed tells Houston, "Al just dropped down on a knee to pick up a rock, and he went in 3 or 4 inches.  Ed has to help Al get up.
133:43:30
Collect a large rock
Working near the rim of Cone Crater, Al collects a 9 kg rock and, although there is no TV coverage, he almost certainly used the same technique used by Dave Scott and Charlie Duke to collect their big rocks: using a long-handled tool for support while kneeling, pressing the rock against his leg, and then rising.

Apollo 15

120:44:01
Keeping clean
In comments on a 1996 draft of the A15LSJ, Dave wrote, "I cannot imagine that a (dirty) suit would not compromise cooling by the PLSS, but maybe we were oversensitized to this issue. Kneeling in the dirt still seems very unattractive to me! More dirt in the cabin, connectors, etc!! After three days of dirt on Apollo 15, I would be even more cautious on the next trip."  See, also, comments after 120:58:47.
125:22:02 Kneeling to put wrench on the drill stems
Dave drilled very deeply and has to put the wrench on the stems very close to the ground.  He uses the drill as a support in getting up.
145:53:23
Going sideways onto one knee
While securing Jim's SCB harness, Dave goes down on his right knee and holds the position for about 5 sections before finishing the job and rising. While he goes down and holds his position, he has his left palm on the back of Jim's PLSS for stability.  There are few (no?) similar instances in the Apollo TV record.
147:36:15
Using the drill for support, saved fall
Dave uses the drill for support as he kneels so he can attach the wrench to the drill stem.  the top of the drill is at about knee height.  He has to reach forward with his righthand and ends up with all his weight on his left hand, with which he is holding the near drill handle, and on his right knee.  His right knee starts to slide under his to his right and he has to use both hands to push himself up and avoid a fall.
147:41:21
Using the drill for support
Dave uses the drill for support as he gets to his knees and tries to put the wrench on the drill stem.  This time, the drill is at about waist height, so he has far less trouble than when it was lower.  Commentary just prior to 147:42:16.
165:32:56
Going to one knee or, perhaps, both knees and picking up his dropped camera without support
After Dave's spectacular trip and fall at the rille, he asks Jim to use the scoop to raise the camera lens barrel into reach.  Jim in unable to do that because the barrel slides away on the soft surface.  Dave then goes down onto one knee - or, possibly, both knees -  and, once he has the camera, rises without difficulty.  He is partly obscured by Jim, so we don't know if he was on one knee or both.  Because Dave grabbed the camera with his right hand, we know he didn't use Jim for support.
165:39:39
Going to one knee, making use of a shelf at the base of the rock
Dave is able to kneel next to a rock by putting his right knee on a shelf at the base of the rock and sticking his left leg out to the side, with his foot noticeably lower than his right knee.  He keeps his back relatively vertical.
166:09:00
Kneeling to collect Great Scott
Dave gets down on both knees, without support.  He is leaning well back, undoubtedly to put his center-of-mass behind his knees to keep his knees bent.  His feet are slightly uphill of his knees, which probably helps him keep his balance.  He has the rock on his right and has a bit of trouble getting his hand low enough to get the rock pressed against the outside of his leg.  The rock is much bigger than his hand.  At one point, he starts to tip to his right, but gets his hand out to steady himself and his left leg out on the other side as a counterweight.  His second attempt goes well and, as he gets the rock onto the outside of his right thigh, he stands easily.

Apollo 16

120:22:55 Kneeling with flagstaff section for support
After failing in his first attempt at a dynamic grab, John uses the upper flagstaff section for support as he goes to his knees to retrieve the lower flagstaff section he had dropped earlier. At 120;24:20, Charlie comments on how dirty John's lower legs are already.  See, also, AS16-113-18339, which Charlie takes soon after.
121:21:21
Kneeling to inspect damaged heatflow cable connection
After John accidentally catches the heatflow ribbon cable on his boot and pulls it loose from the Central Station, he kneels twice as he assesses the damage.  He  uses a 30-cm rock for  support on the first occasion;  on the second occasion, once his is on his knees, he takes hold of a protruding piece of attachment hardware for a bit of stability.  He is remarkably stable throughout this sequence.
121:26:12 Kneeling with the drill for support
For his second attempt to attach the wrench, Charlie puts his right hand on the drill for support while he gets to his knees.  His posture suggests that the internal suit pressure is keeping him from getting all of his weight on his knees.
121:37:04
Kneeling with the chest-high drill stem for support
Holding on the the drill stem with his right hand, Charlie drops easily to his knees
121:45:34
Repeatedly dropping to the knees to work the jack
Charlie gets maximum utility from the jack by dropping to his knees on each stroke and "letting the suit do the work" of getting up.
123:59:15 Using the scoop/shovel for support
Charlie puts the head of the scoop perhaps 1.5 meters out in front of the his feet and leans on it with his left hands as he sinksto his knees. Initially, he has his back nearly vertical and can't reach low enough to pick up the rock fragment John pried off the partially-buried boulder.  He leans forward till his back is about 30 degrees off vertical, moves himself perhaps 30 cm to his right, and grabs the fragment.  He gets to his feet without difficulty, not having moved the scoop head at all.  Charlie uses the technique again at 124:04:44 and at 124:06:34.
124:08:01 Using the scoop for support  while collecting Big Muley
This time, Charlie is much closer to the Rover and we get a good look at the technique and what he has to do the pick up this very large rock, the largest single sample returned from the Moon during Apollo.
165:59:44
Kneeling while working on LMP PLSS
John kneels while attaching the bottom straps on Charlie's Sample Collection Bag (SCB).  Motions of Charlie's PLSS suggest that John uses him for some support.  Another example can be found at 122:52:32.

Apollo 17

118:25:54
Kneeling at the MESA
Because the MESA is lower than expected, Gene has to get on his knees to remove the drill.  With the MESA for support, he has no trouble staying down or getting up. Partial TV.
120:33:02
Kneeling with the drill for support
Gene is unable to seat a new drill stem in the one in the ground and leans on the drill so he can get on both knees.
122:18:17
Using the scoop for support
Gene kneels at the Station 1 boulder to hammer off some fragments, but can't get properly positioned to effectively wield the hammer.  He uses the scoop as a support, moves his knees back 20-30 cm and leans forward on the scoop with his left hand while he hammers with his right.  He has his back to the TV.  With the scoop as a prop, he gets up easily.
123:13:03
Kneeling and using a partially buried boulder for support
On his way back to the LM, Jack stops to inspect a boulder that is perhaps 3-4 meters across with only about 20 cm sticking out of the ground.  He lets himself fall forward until he is leaning on the boulder with his knees on the surrounding soil.  He gets up on his second try at pushing back to get his center-of-mass behind his knees.
145:27:50
On hands and knees to retrieve the scoop
Before retrieving the dropped scoop, Jack kicks it to his right so that, when he drops to his hands and knees, his feet will be downslope of the scoop, perhaps in a small crater.  This will give him leverage when he pushes back off his hands to rotate his center-of-mass far enough back that he can stand.
145:32:42
Getting to one knee on a slope
The surface near the orange soil slopes shallowly upward from the direction of the Rover.  To get a scoop of soil out of the trench, Jack gets his right foot downslope and lowers himself onto his left, upslope knee. Similar situation to Dave Scott's at 165:39:39.  Jack tries a similar technique soon after at the south end of the trench, but loses his balance.
166:59:49
Using Gene's hand for support
Jack goes to his knees to get a fragment Gene hammered off the Station 8 boulder.  Two minutes later, we see Jack on hands and knees examining the boulder.
167:04:26 On hands and knees to roll the Station 8 boulder
Gene has his back to the Rover, so we don't get good views of him getting down or getting up, we do get a good view of the vigorous push he gives the boulder with his right hand, while balancing himself on his left.

5. Falling


The following table is probably imcomplete, but is certainly representative of the Apollo experience.


Instances of Apollo Astronauts Falling and
Circumstances in which care was taken to avoid falls


Ground Elapsed Time (hhh:mm:ss) Type Notes

Apollo 11: no known falls

109:44:23
Potential of fallling when jumping
Armstrong, from the 1969 Technical Debrief - "I would say that balance (while walking) was not difficult; however, I did some fairly high jumps and found that there was a tendency to tip over backwards on a high jump.  One time I came close to falling and decided that was enough of that."  Note that Charlie Duke attempted a high jump during Apollo 16 (see below).  He tipped over backwards and landed on his PLSS, fortunately without any consequences other than a momentary fright and a bit of wounded pride.
111:34:36
Slippery surfaces
Crew comments on tendency to slip while  using the Lunar Equipment Conveyor (LEC); and on various factors that could make footing difficult.  Later crews did not comment on these issues, probably having had the benefit of knowing what to expect and having more time to adapt to lunar conditions.  Apollo 11 was the only crew to do much walking - as opposed to hopping or running - which may have also been a factor.

Apollo 12: two probable falls

115:27:19
New posture
Early in the first EVA, Al Bean comments that, because of the weight of the backpack, they are having to lean far forward to get their center-of-mass over their feet.  "On Earth, you'd fall over (leaning so far forward)."  Adjusting to this  new posture took a few minutes.  Additional comments about not moving backwards.  Pete Conrad mentions that, contrary to comments by the Apollo 11 crew, he did not notice that the ground felt "slippery".
115:30:20
Stumble, no fall
Pete after telling Al, who is still in the LM, "you've really got to watch your step down here." A moment later, while adjusting the height of the MESA, he says "I almost fell."
117:19:03
Probable fall
Bean discusses the greater hazard of moving backwards rather than forwards and mentions that "I tripped a couple of times going backwards."  One such instance may have happened at 117:32:04.
118:25:59
Probable fall
Bean probably fell; but got up without difficulty.  Conrad may have helped him get up.  In 1991, Bean remembered, "I fell down a couple of times." 
132:46:22
Wary of steep slopes
Conrad and Bean had a "safety line" which they might have used in case one of them needed help getting out of a crater.  It was no more than about 10 meters long and was never used.  They thought about going into Bench Crater but decided that the walls were too  steep and the danger of falling was too great.  With regard to the latter, they seem to have been concerned primarily with falling in a position from which it would be difficult to get up.  For example, on their back with head downslope.  Later crews gained experience with steep slopes and, during Apollo 17, getting up from a difficult position.
136:51:56
Pete fell
During the post-EVA-2 debriefing, Pete said, "I fell over once out there, and Al picked me back up again.  It's no big deal."  The time when this happened has not been identified.

Apollo 14: One possible stumble or near fall

118:15:33
Stumble, saved
Off camera, Al Shepard may have stumbled while working around the ladder during EVA-1 close-out.  The dialog suggests that he caught himself by grabbing the MESA.  In a section of the Technical Crew Debriefing reproduced after 113:52:26, Al says he did not fall during either of the EVAs.  Comments about stability and ease of adaptation.
135:16:39
Cable snag, no fall
During the EVA-2 close-out, Al repeatedly snags the TV cable with his foot and at 135:24:38, actually pulls the TV over.  He does not appear to stumble during any of these episodes.

Apollo 15: 3 falls, 1 possible fall, 4 saves, 3 stumbles

120:02:47
Saved fall
The footpad on the ladder strut is not resting firmly on the ground and is free to move.  When Jim Irwin steps on the footpad for the first time, it rotates under him and he saves himself from a fall by grabbing the right handrail.
120:11:24
Cable hazard
Jim moves the TV cable so they don't trip over it during Rover deployment.
120:16:05
Fall walking backwards
During the LRV deployment, Jim backed away from the LM pulling a lanyard and trying to take pictures at the same time.  He was off camera when he tripped and fell.  Dave Scott gave him a hand getting up.  Later, he learned to get up by himself.  "It wasn't difficult ... but it was much easier, you know, to get your buddy to lift you up."  Technique described.
120:42:29
Off balance, saved fall
Dave loses his balance while installing the LCRU on the front of the Rover.  He hops in the direction of the fall, which gives him time to get his hand onto the Rover wheel to steady himself.
120:44:01
discuss care versus efficiency
Discussion of the relative value of (1) trying to keep clean, (2) brushing the suits after a fall or saved fall to avoid excess use of cooling water, or (3) letting the suits get dirty in the interest of using the limited time available most efficiently.  The Apollo 16 and 17 crews made little effort to keep clean and only brushed each other off at the end of each EVA. They threw themselves into their work and fell more frequently. For longer lunar stays, dust control will be essential.
122:43:06
Stumble, no fall
Dave tries to get a sample bag low enough for Jim to reach and stumbles forward.
123:00:46
working on slopes
Working on a hillside at Station 2, Dave has to find a way to stand so he can hold a sample bag low enough for Jim to reach.  Working on slopes required care to avoid falls.
124:01:38
possbile fall during Rover dismount
Back at the LM at the end of the EVA-1 traverse, Jim may have fallen.  Dave wants to look at Jim's camera in case it needs dusting.
124:48:02
Saved fall
Dave attempts a spinning throw - like an Olympic discus thrower - of an empty experiment pallet.  His spin continues after he releases the pallet.  He is off balance but gets his right hand on the ground for some stability and ends up on his feet.
143:54:33
Rover dismount on steep slope At Station 6, Dave parked with the Rover pointed uphill on an 11-degree slope.  Dave warns Jim about the possibility of falling backwards when they jump out of the seats.  Dave may have helped Jim dismount.
144:13:00
stumble, no fall
Dave stumbles slightly while turning to get some sunlight on a rock he is examining.
145:01:44
Rover dismount on steep slope
At Station 6a, Dave had to park on a steep slope with Jim on the downslope side of the Rover.  Dave warns him to be careful jumping off his seat.
145:30:28
Difficulty of bending back to look up without falling
At Spur Crater, Dave is trying to use a sighting scope to point the high-gain antenna at Earth.  He asks Jim to look up at Earth to help him get a rough alignment but Jim decides that, because Earth is so high in the local sky, he would fall if he tried. The sighting scope was re-configured for Apollo 16 and A17, primarily to give a brighter image of Earth.  Here, Dave used LCRU Automatic Gain Control output to get a rough alignment.  The only way to look overhead in the suits was to use the ladder or some other firm support while leaning backwards or turning sideways.
143:56:37
Working on a slope
Jim decides to omit the uphill frames of a panorama because of the difficulty of leaning backwards.
144:27:45
Uphill fall on a steep slope
Dave tries to climb out of a steep crater and loses his balance because of the soft surface.  He starts to fall to his right but stops that component of the frall with his right hand.  Jim helps him up.
145:49:15
Stumble, no fall
Jim stumbles, but does not fall, while standing on the slope just inside Spur Crater taking pictures.
146:08:28
Maintaining balance while collecting large rocks
While off-camera, Jim collects a 4.8 kg rock.  The dialog suggests that he uses the same technique used by Dave used at Station 9a and by Charlie Duke at Apollo 16 Station 1.
147:37:03
Off balance, saved fall
Dave loses his balance while trying to attach a tool to the drill stem.  He starts out on his knees and has his left hond on the near drill handle for support.  He has to reach far forward to attach the tool with his right hand.  As he extends his reach, his left knee comes off the ground and his right knee starts to slide toward his left.  Because of the weight of the backpack, he starts to rotate to his right onto his back.  To catch himself, Dave grabs the drill with his right hand and pushed up with his right foot. As he comes up, he gets his right leg under his center of mass and, with his left leg stuck out behind, spins through about ninety degrees. As he brings his left leg down, he makes a few short steps away from the drill and, finally, brings himself to a stop with a two-footed hop. The elapsed time from the start of the fall to the end of the final hop was almost six seconds and this episode is a dramatic illustration of the length of time one has to respond in one-sixth gravity.
149:02:04
Suit dirty from falls
While using the dust brush on Dave at the end of EVA-2, Jim Irwin wonders why the front of Dave's suit is so dirty.  He then remembers that Dave has saved himself from some spectacular falls, spraying dust around in the process.
165:32:00
Spectacular fall after tripping
While describing details he can see in the far wall of Hadley Rille, Dave is walking forward and trips over a rock he hadn't noticed.  He fell onto his hands and knees and, as his momentum carried him out of the TV field-of-view, he was rolling onto his right side.  Jim goes to him to help him get up but, by the time Jim arrives, Dave is up. Unfortunately, he was still off camera when he got up.  To retrieve the Hasselblad he was carrying, Dave drops to his right knee, grabs the camera, and gets up without difficulty.  One-sixth grvity and the soft surface made this fall much less dangerous than it would have been on Earth.

Apollo 16: 12 falls, 4 saves

120:08:35
Loss of balance, no fall
Charlie Duke loses his balance trying to tug loose the Velcro holding his seat back down.
121:11:53
Dynamic grab, no fall
Charlie bobs down to get the wrench off the drill string.  He had his right leg well forward and his left well back and got the wrench off without losing his balance.  They discuss the technique, which John developed during training in the 1/6th-g aircraft, at 119:24:37.
121:29:52
Off-camera fall
Charlie Duke falls while trying to remove the drill from the deep-core stems.  TV of him having some trouble getting up from his hands and knees.  He will learn to get up more efficiently than he did this time.  At 122:51:29, during preparations for the geology traverse, John Young comments on the amount of dust Charlie has on his suit and/or PLSS.
121:53:10
Loss of balance, no fall
Charlie loses his balance while trying to bob down to grab a rock off the surface.  Because lunar gravity is weak, he has time to recover without falling.  First try at getting up doesn't work but then masters the standard technique of getting on hands and knees and then pushing with his hands so he rotates backwards with his knees and lower legs staying on the ground.  Once his center-of-mass is behind his knees, he rises easily.
122:40:42
Dynamic grab, minor fall Off-camera, Charlie falls while solo sampling, probably while trying to bob down to grab the rock.  He has some trouble getting up and, after he is up, checks to make sure his camera lens is clean.
123:42:57
Dynamic grab, minor fall
Off-camera, John tries to bob down to grab a fallen sample bag and falls.
124:08:29
Care while collecting very large rock
Charlie collects the sample known as Big Muley from the rim of Plum Crater, using the same technique used by Scott and Irwin.  He is very careful and does not lose his balance.  At 11.7 kg (26 pounds), it is the largest sample collected during Apollo.
125:32:23
Controlled fall
John dropped the dustbrush and, as he bobs down to grab it, loses his balance.  Gets himself turned during the fall so he lands on his hands and knees.
125:46:07
Ladder climbing
John climbs the ladder using only one hand on the rails and rungs.  He has a rockbox in his other hand.  Charlie urges care.
144:35:31
Minor fall while  getting up Charlie ended up on his hands and knees  when the penetroeter went all the way into the ground on a steep, soft slope at Station 4.  He falls while trying to get up.
145:28:02
Loss of balance on a soft slope, no fall Charlie loses his balance while working on the soft, inner wall of a crater but runs in place until he can plant the rake and catch himself.
146:26:40
Fall while mounting the Rover
When Charlie tries to jump into his Rover seat, his PLSS hits the seatback and he falls.  John decides they will brush Charlie's lens at the next station.
147:54:48
Fall getting off the Rover
At a level site, Charlie has trouble dismounting and falls when he does get out.  After John helps him up, he checks to make sure his camera lens is clean.
149:12:03
Minor fall while  getting up
Charlie ended up on his hands and knees  when the penetroeter went all the way into the ground at a level site.  He falls while trying to get up.
166:58:18
Dynamic grab, minor fall
John bobs down to grab some fallen bags.  It takes him an extra second or saw to get them in hand and, during that second, he starts to lose his balance and falls as he starts to rise.  He gets up with a novel technique.
167:13:09
Loss of balance, minor fall
Off-camera, Charlie falls while trying to retrieve an SCB.
168:39:18
Fall in awkward position
Off-camera, Charlie falls, probably while picking up a sample he has broken off Shadow Rock.  He ends up on the ground next to the rock and has to have John's help to get up.
170:21:44
Dangerous fall
After John does a few jumps, learning to control his balance by doing a series of jumps that start small and get larger and holding the Rover for stability as he gets started, Charlie does one small jump and then one very large one.  By the time he gets to the top of the jump, he is leaning backwards by 20-30 degrees and, although he lands momentarily on his feet, he cannot keep himself from falling backwards onto his PLSS, fortunately with no damage.

Apollo 17: 9 falls, 1 save, 5 stumbles

117:21:16
stumble, no fall
Early in EVA, Jack Schmitt stumbles but does not fall. No TV.
117:36:06
minor fall
Gene Cernan falls while trying to pick up a dropped tool. "Well, I found how to get up!"  No TV.
117:52:45
minor fall
Jack falls while trying to pick up a rock.  No TV.
118:28:27
Stable posture for looking up, no fall
Discussion of a stable posture Jack uses to look up at equipment on the top of the LM.
119:35:45
stumble, no fall
Gene stumbles while trying to take the wrench off the drill-stem rack.
119:49:04
spinning throw, almost falls
Like Dave Scott during the Apollo 15 ALSEP deployment, Gene does a spinning throw and almost falls.
121:00:59
Spectacular spinning fall
While taking a turn using a jack-and-treadle to remove the deepcore, Jack throws all his weight onto the jack handle, loses his balance, and ends up in a spectacular, spinning fall.  Gene helps him up.  Although Jack is mostly hidden by Gene, as he gets to his feet we can see Gene's right hand on Jack helmet near the top of the visors.  Gene may have been pushing back on Jack's head to help him up.  While he is down, Jack doesn't get his knees bent more than about 60 degrees.
121:38:18
stumble, no fall
Jack stumbles on a rock near the LM.  No TV.
122:13:01
stumble, no fall
Gene stumbles slightly on a fist-sized rock while climbing out of a crater.
122:15:55
stumble, no fall
Jack stumbles while trying to raise the scoop handle high enough to pour a sample into a bag Gene is holding as low as he can.
123:09:08
Need for support when leaning low
The solar panels on the SEP receiver wouldn't stay open on their own, so Jack had to put some duct tape on them.  Because he had to put the tape on at about knee height, he had to lean on Gene to keep his balance.  The TV was not pointed at them during this activity.
145:28:39
Getting up in 1/6th gravity
Cernan comments: "This is not meant as a criticism, but I think that Jack tended to fall more than the rest of us did.  And it's maybe because he became more aggressive.  And, thank God for one-sixth gravity.  You would have dropped things anyway because of the lack of nimbleness and dexterity and you would have wanted to get down to pick things up and chip rocks and what have you.  And one-sixth gravity made getting back up a lot easier than it would have been otherwise."
144:02:16
Minor fall
Off, camera, Gene falls when trying to mount the Rover at the Scarp Gravimeter stop.  He is able to hold on to the Rover to make getting up easy.
144:50:52
Minor fall
While working on the outer slope of the raised rim of Ballet Crater  Jack goes to one knee to pick up a dropped SCB and falls trying to get up.  Ballet Crater got its name because of the efforts Jack had to make repeatedly at this site to retrieve dropped tools.
144:56:23
Minor fall
Jack responds to CapCom Bob Parker's remark about the Houston Ballet calling to request Jack's services for the coming season by doing one-footed hops on his right leg with his left leg extended back and up.  He is clearly playing.  He loses his balance and falls to his hands and knees.  Discussion about confidence in the suit as long as there was no chance of falling on a sizeable rock.
146:36:38
Working in a boulder field
Need for caution in the boulder field on the rim of Camelot Crater
147:53:35
Discuss distribution of dust on the suits
While dusting each other off at the end of EVA-2, Gene mentions that, during his fall while trying to get on the Rover at the Scarp Gravimeter stop, he only got his outboard (left) arm dirty and not his inboard (right) arm.  Also discuss the amount of time spend dusting each other.
164:59:13
Working on a steep slope
Off-camera, Gene has trouble reaching surfaces on the front of the Rover that need dusting.  He decides to defer the dusting to the next stop.  Additional comments at 165:04:48.
165:24:10
Off-camera fall
While sampling on a particularly steep slope - as evidenced by the fact that both astronauts are using the high colling setting - Jack falls while trying to pick up a chip he has broken off one the boulders.
165:36:33
Spectacular fall
While running cross slope to limit his downslope speed, caught his trailing left foot on a small mound or crater rim and started to fall.  He was able to control the fall and ended up on his hands and knees.  Once he gets his feet downhill, he pushes back to get his center-of-mass over his knees and rises without difficulty.  In 1992, Schmitt commented that, by this third EVA, they had a great deal of confidence  and didn't worry much about falling.  Presumably, they were confident in the suits and in their ability to get up when they did fall.  They also knew they would fall slowly in 1/6th-g and that, in the absence of large rocks, the surface was soft.
166:00:29
Working on a slope
Because Jack's seat in on the downhill side of the slope at Station 6, Gene decides to drive the Rover to a more level spot and let Jack get in his seat there.
167:33:28
Minor fall; difficulty getting up from awkward position
At Station 8, Gene parked facing mostly uphill but, apparently, with his side slightly uphill and Jack's slightly downhill.  When Gene tries to jump into his seat at the end of the stop, he falls and is pinned by the slope against the Rover, possibly with his feet uphill.  Gene needs Jack's help in getting up and has him push back on his helmet.


6. Getting Up

The following table is probably not complete, but is certainly representative.   The included examples generally have good TV coverage.

Getting up efficiently after kneeling or a fall required practice.  Each of the astronauts was a lot better at getting up by the end of EVA-3 than during EVA-1.  A variety of techniques were tried.    Getting up was easiest if a means of support was available.  If none was available, the easiest way to get up was to get on hands and knees and then push back with the hands to rotate the torso and PLSS far enough back that the astronaut's center-of-mass was over his feet.  At that point, it was easy to hop up and stand.


Ground Elapsed Time (hhh:mm:ss) Type or circumstance Notes

Apollo 15

144:27:45
Help from LMP
After Dave's fall on the steep, inner wall of the Station 6 crater, he gets on his hands and knees with his weight primarily on his left knee, which is almost on the crater rim, and his left hand, which he has planted just in front of his left knee.  Dave's right knee is slightly downslope and he holds out his right hand for Jim's help.  Jim gets in position in front of Dave with his right foot forward and well planted, his right knee slightly flexed, and his left leg well back.  Jim extends his right hand and holds his arm steady so Dave can use Jim for leverage.  Dave starts to rise, scrambling forward and Jim moves back to get Dave on the level surface outside the rim.




Apollo 16

121:21:21 Two kneeling events
After John accidentally catches the heatflow ribbon cable on his boot and pulls it loose from the Central Station, he kneels twice as he assesses the damage.  He  uses a 30-cm rock for  support on the first occasion but does not appear to use any support on the second.  He is remarkably stable getting up on both occasions.  On the first, he leaned on his left hand, moved his right foot forward and inward and then rocked his torso back far enough that he could push himself up with his right leg.  Finally, he brought his left leg forward and was upright.  On the second, he is on both knees, rocks back to get his center-of-mass over his feet, and rises easily.  He finishes with a slight hop backwards to regain his balance.
121:29:52
Getting up using 10-20 cm of drill stem as a support
Charlie falls off-camera while trying to remove the wrench.  Fendell pulls back on the TV zoom and finds Charlie on his hands and knees.  He has his right hand on the 10-20 cm of drill stem sticking out of the ground.  He pushes himself up slightly with his right hand, maintaining his grip on the stem, and pulls his knees forward until they are under his chest.  He rises from that position, letting the internal pressure of the suit do some of the work and pushing himself up and forward with his feet somewhat like a sprinter coming out of the starting blocks. He runs forward until he has his feet under his center-of-mass.  This is a side view.
121:37:04 Rising using the chest-high drill stem for support
Charlie uses the drill stem for support as he drops to his knees, gripping it with his right hand.  In getting up, he maintains his grip and seems to let the suit do more of the work that in the previous example.  Once he is part way up, he shifts his weight onto his right foot forward and pushes up and forward with that leg while he moves his left leg forward.  He moves forward a step or two to get his feet under his center-of-mass.  This is a front view.
121:43:36
Rising by leaning or pushing back
Charlie got the treadle-and-jack off the Rover for removal of the deep core.  Almost off-camera, he knelt next to the knee-high stem, probably to remove the wrench, and may have used the wrench as support in getting down. His back is vertical.  Once he has the wrench off, he leans back until his center-of-mass is well behind his knees and rises much more easily than in the prior two examples, with no running forward to regain balance
121:53:10 Rising by pushing back with the hands
After saving himself from a fall in his attampt to grab a rock off the surface, Charlie goes to his knees and then rotates forward onto his hands.  One he has the rock, he pushes back a little a tries to run forward under his center-of-mass.  He doesn't make it and falls onto his hands and knees.  He then pushes back hard and once his weight is well behind his knees, rises without difficulty.  This is the standard technique.
149:11:49 Difficulty rising from hands and knees
After the penetrometer unexpectly - and rapidly - sinks to full depth, Charlie starts to fall and catches himself with his right hand.  He ends up on his hands and knees.  On his first attempt to get up, he has his weight on his hands and toes and, when he pushs with his hands to get his torso to rotate up and back, the fact that he didn't have his knees in solid contact with the ground defeats the effort.  On his second attempt, he gets all his weight on his hands, kicks his feet up and, as they come down, pushes up with his hands.  His chest rises about a meter or so off the ground and, at that point, he tries to run forward to catch himself.  He doesn't make it and falls forward.  On his third attempt, he lowers his chest to the ground and, although he has little weight on his knees, push back hard enough that his center-of-mass rotates back far enough that he can spring upright.  Charlie is not yet proficient in getting up from his hands and knees.
149:13:27
Getting up from an erect kneeling position
The penetrometer goes to full depth again, but more slowly.  Charlie ends up on his knees but with his hands still on the penetrometer.  He then leans back until the bottom of his PLSS is touching his heels and holds that position for  a few seconds and wonders if he'll be able to get up.  He decides to try, bounces on his knees slightly and has no trouble standing.  He is learning to use the suit and the weakness of lunar gravity.

Apollo 17

120:57:05
Using the core stems as a crutch
After a second session of jacking the deep core out of the ground, Gene stands to rest, using the waist-high core stem as a support in getting up.  He has been working hard.
121:00:59
Getting up from hands and knees with Gene's help
After Jack spectacular fall at the deep core, he ends up on his hands and knees. Although Jack is mostly hidden by Gene, he can see that his knees are bent no more than 60 degrees.  As he gets to his feet we can see Gene's right hand on Jack helmet near the top of the visors.  Gene may have been pushing back on Jack's head to help him up.  This may be what Jack will do to help Gene up from his fall against the side of the Rover at Station 8 at 167:33:28.
123:13:03 Getting up from hands and knees
On his way back to the LM, Jack got on hands and knees to inspect a partially buried boulder.  On his second try, he is able to push his center-of-mass far enough back that he can hop to his feet.
145:27:50 Jack gets up from hands and knees with his feet somewhat downslope
Before retrieving the dropped scoop, Jack kicks it to his right so that, when he drops to his hands and knees, his feet will be downslope of the scoop, perhaps in a small crater.  This will give him leverage when he pushes back off his hands to rotate his center-of-mass far enough back that he can stand.
165:36:33
Getting up from hands and knees on a slope
After Gene's spectacular fall at Station 6, he ends up on his hands and knees.  He turns himself until his feet are downslope, pushes back with his hands and, once his center-of-mass is far enough back, hops to his feet.  Because of the slope, he doesn't have to push hard with his hands nor rotate his PLSS quite as far back.
167:02:22
Three tries to get up from hands and knees
While Fendell was following Gene with the TV, Jack got on hands and knees to examine the Station 8 boulder.  After Gene returns, we see Jack take threee tries to push him self back far enough that he can stand.  Good TV.  Two minutes later, Gene gets on hands an knees so he can turn the boulder over.  It takes him two tries to get up.  Because he has his back to the Rover, we don't get as good a view of the mechanics of getting up.



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