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Author
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Topic: Could a moonwalker have carried another?
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Paul78zephyr
Member Posts: 246
From: Hudson, MA
Registered: Jul 2005
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posted March 26, 2011 08:41 PM
  
In all the contingency plans NASA made for dealing with an incapacitated moonwalker did they ever consider the possibility of one moonwalker carrying the other - especially in the pre-rover missions? What was the total average weight of a moonwalker in his suit on the moon? Would it even have been physically possible to lift an astronaut given the limited range of movement in the suit? |
MCroft04
Member Posts: 1085
From: Smithfield, Me, USA
Registered: Mar 2005
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posted March 26, 2011 10:13 PM
I don't know if NASA simulated this possibility. But where there's a will, there's a way. Given the 1/6 gravity, and having met many of the moonwalkers who are all over-achievers, my money is on them being able to carry their partner back to the LM if necessary. But good question and I'm anxious to hear if anyone knows if NASA considered this possibility. |
Blackarrow
Member Posts: 1702
From: Belfast, United Kingdom
Registered: Feb 2002
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posted March 27, 2011 01:05 PM
A far bigger problem would have been to get the unconscious astronaut back inside the LM. I suggest that this would not have been possible. If the unconsciousness was temporary, better to wait for the victim to regain consciousness. Anything likely to render an astronaut unconscious for any length of time would probably have had fatal consequences, and I doubt if the NASA doctors would have wanted the healthy astronaut to risk a heart-attack trying to force his unconscious buddy through the LM hatch. |
Obviousman
Member Posts: 405
From: NSW, Australia
Registered: May 2005
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posted March 28, 2011 02:57 AM
I seem to remember the hatch scenario being mentioned somewhere; it was believed to be impossible for one astronaut to get an unconscious partner up the ladder and in the hatch. This was based on multiple attempts during training, and the instructions were that if one could not get into the LM, they'd have to be left behind. |
Tykeanaut
Member Posts: 1070
From: Worcestershire, England, UK.
Registered: Apr 2008
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posted March 28, 2011 04:26 AM
Didn't they have an emergency tether on the LM? Some sections of the Apollo 14 tether come up for auction now and then.I don't know if this would have worked however. |
moorouge
Member Posts: 1089
From: U.K.
Registered: Jul 2009
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posted March 28, 2011 05:20 AM
I tend to agree with Obviousman. Any injury that would prevent ingress to the LM would have resulted in the injured party being left behind. This does not mean that no attempt would be made, but it does mean that at some point a very harsh and difficult decision would have to be made. I do not envy the Flight Director at MSC who would have had to make the call.As I recall, the only contingency plan was the use of a 'buddy' system in the event of a suit puncture. |
Robert Pearlman
Editor Posts: 23493
From: Houston, TX
Registered: Nov 1999
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posted March 28, 2011 08:26 AM
quote:
Originally posted by Tykeanaut:
Didn't they have an emergency tether on the LM?
They had the Lunar Equipment Conveyor (LEC), which according to the Apollo 11 Final Lunar Surface Operation Plan (via ALSJ) "may also be used by the crewmen as a safety tether... as an aid in ascending to the ascent stage."The LEC was attached by carabiner to the crewman's neckring tiedown strap on one end and to a pulley hanging from the LM's cabin ceiling on the other. The question is: could the conscious crew member in this scenario attach the LEC to his incapacitated partner, ascend the ladder and enter the LM, and then pull his crewmate up the ladder and then through the hatch? |
jasonelam
Member Posts: 353
From: Monticello, KY USA
Registered: Mar 2007
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posted March 28, 2011 10:04 AM
The "Buddy System" unit, or BSLSS (Buddy Secondary Life Support System), went into active service on Apollos 14-17 as moonwalk distances increased. It was only designed for sharing cooling water between the two astronauts. It was not designed for oxygen flow between the two. I agree with Obviousman and Moorouge that if there were any injury that would leave an astronaut incapacitated on the surface and prevent ingress that there would simply be no other choice but to leave them on the surface. Fortunately, it never came down to that. As for using the LEC to pull up an injured astronaut, it might be possible, but it also depends on how much weight the LEC can hold and if the astronaut did not get snagged on something (like the ladder rungs) on the way up.
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Robert Pearlman
Editor Posts: 23493
From: Houston, TX
Registered: Nov 1999
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posted March 28, 2011 10:31 AM
Another consideration would be to remove the incapacitated crew member's PLSS at the base of the LM ladder (or on the porch), making it easier for him to be pulled through the hatch. Yes, it would leave him with only the air in his suit, but if the only alternative is to leave him on the surface to die, the risk might be deemed acceptable. |
Blackarrow
Member Posts: 1702
From: Belfast, United Kingdom
Registered: Feb 2002
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posted March 28, 2011 05:02 PM
Robert, leaving the Oxygen Purge System in place would have provided the unconscious astronaut with around 30 minutes of air. But there's a further problem: in the world of science fiction, that would have been enough for a dramatic rescue. In the real world I suspect that after two hours the Flight Director would have had to make his worst-ever call. |
MCroft04
Member Posts: 1085
From: Smithfield, Me, USA
Registered: Mar 2005
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posted March 28, 2011 06:46 PM
I'm reminded of the story Jim Lovell tells about flying off a carrier and losing all the lights in his cabin. After pondering a while on what to do, he noticed the trail in the ocean from fluorescent phytoplankton, which allowed him to find the ship and land safely. Sure, getting an unconscious astronaut back into the LM would have been difficult. But there do appear to have been options (e.g. the tether) and my money would be on these highly creative guys figuring out a way to get it done. Perhaps a good topic at the next ASF cocktail party. |
Skylon
Member Posts: 94
From:
Registered: Sep 2010
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posted March 28, 2011 10:17 PM
I hate to say this, but I could see this being filed under "if it happens, you're probably dead."What exactly are we imagining could incapacitate a moon walker? Short of a twisted ankle, which you could maybe limp home on, when I hear incapacitated I imagine: A) A heart attack, or something similar...in which case it would be near impossible to administer any first aid in time. B) A broken bone, or other form of physical trauma, which, if the trauma has done that to you, probably had the force to puncture the EVA suit or damage it. |
MCroft04
Member Posts: 1085
From: Smithfield, Me, USA
Registered: Mar 2005
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posted March 29, 2011 08:39 PM
How about a mini stroke causing temporary paralysis? Or severe cramps? I'm sure a medical doctor could share numerous ways an astronaut could become incapacitated while on the lunar surface without being fatal. I doubt a broken bone would have occurred on the moon. First bones are protected by the rigid spacesuit, and then in 1/6 gravity there would have been much less stress exerted on the body from a fall or similar event. But if an astronaut had been injured on the moon, I would have given them at least a 50/50 chance of being dragged, pushed, or pulled back into the LM. |
moorouge
Member Posts: 1089
From: U.K.
Registered: Jul 2009
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posted March 30, 2011 02:10 AM
This strikes me as being an excellent project for a school experiment. All that is needed is a ladder, a platform, a correctly sized opening (hatch) and a LM interior box.There are many teachers here on cS, so how about it? |
Blackarrow
Member Posts: 1702
From: Belfast, United Kingdom
Registered: Feb 2002
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posted March 30, 2011 06:30 PM
quote:
Originally posted by moorouge:
All that is needed is a ladder, a platform, a correctly sized opening (hatch) and a LM interior box...
...and a lot of money to hire a "vomit comet" to simulate one-sixth "gee." |
moorouge
Member Posts: 1089
From: U.K.
Registered: Jul 2009
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posted March 31, 2011 11:16 AM
quote:
Originally posted by Blackarrow:
...and a lot of money to hire a "vomit comet" to simulate one-sixth "gee."
Not necessarily. All one needs apart from those already mentioned is a dummy of similar proportions to an astronaut and weighted to simulate what he would have weighed on the Moon.I suspect that the main difficulty would have been getting the incapacitated astronaut through the hatch and not up the ladder. To push or to pull - that is the question. |
Lou Chinal
Member Posts: 864
From: Staten Island, NY
Registered: Jun 2007
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posted March 31, 2011 02:13 PM
As I remember it Grumman was steadfast against having two astronauts on the ladder at the same time. Initially they felt that one guy should be left in the LM at all times. There was a big fear (I'm not sure by who) that an astronaut would fall and break his leg. A compound fracture might puncture the suit.I agree with MCroft04 and moorouge. I can't imagine what trauma would incapacitate the astronaut while leaving the suit intact. |
ivorwilliams
Member Posts: 57
From: Welwyn Garden City, UK
Registered: Jan 2005
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posted April 07, 2011 09:22 PM
quote:
Originally posted by moorouge:
All one needs apart from those already mentioned is a dummy of similar proportions to an astronaut and weighted to simulate what he would have weighed on the Moon.
But I would expect that more effort would still be required on Earth than on the moon even if a dummy of 1/6th earth weight was used. The able bodied astronaut would still be subjected to 1g. |
moorouge
Member Posts: 1089
From: U.K.
Registered: Jul 2009
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posted April 09, 2011 01:53 AM
One mustn't confuse mass with weight. |
canyon42
Member Posts: 84
From:
Registered: Mar 2006
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posted April 09, 2011 06:44 AM
I don't think ivorwilliams is "confusing mass with weight." I believe the point is that even if the dummy is weighted 1/6 normal for the simulation, the weight of the live astronaut (and his suit and equipment and so on) must also be taken into account somehow or it is not an accurate simulation. |
moorouge
Member Posts: 1089
From: U.K.
Registered: Jul 2009
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posted April 09, 2011 07:42 AM
I think that the weight of the live astronaut is irrelevant. His strength is not affected by gravity. The point of the exercise is to determine whether he would be able to hoist the inert body up the ladder and then manoeuvre this body through the hatch. As I said previously, does one push or does one pull? |
Robert Pearlman
Editor Posts: 23493
From: Houston, TX
Registered: Nov 1999
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posted April 09, 2011 08:16 AM
quote:
Originally posted by moorouge:
His strength is not affected by gravity.
His strength may not be affected but his ability to maneuver and steady himself in the lower gravity environment of the Moon is certainly a factor, as is the extent of mobility provided by his suit. |
ilbasso
Member Posts: 1246
From: Greensboro, NC USA
Registered: Feb 2006
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posted April 09, 2011 03:02 PM
Even in 1/6 gravity, a fully-suited astronaut with a PLSS weighed 50-60 pounds. That's a lot to carry in your arms in a very stiff suit. You couldn't carry the incapacitated astronaut on your back or shoulders because of your own PLSS, OPS, and the antenna. Maybe you could put his feet on top of your feet and dance him slowly across the surface. Too fast, and he'd easily bounce off of your feet. |
canyon42
Member Posts: 84
From:
Registered: Mar 2006
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posted April 09, 2011 03:17 PM
While his strength might not be affected by gravity, what he can ACCOMPLISH with that strength certainly is. Carrying someone else up a ladder also means that you are exerting a lot of energy to carry yourself up the ladder as well. (I might find climbing a steep and tall ladder a challenge under normal conditions, but much easier under reduced gravity.) A change in gravity changes both of those factors. The changing weight of the suit (and as Robert pointed out its flexibility and mobility) is yet another factor. Ignoring any of those would make for a less-than-definitive simulation.I would agree that in all likelihood the biggest challenge would be getting the immobile astronaut through the hatch. One question I haven't see addressed here is the size of the porch. Was there enough room on it to put an incapacitated astronaut down for a moment, along with space for the carrying astronaut to stand? If not, it is hard to imagine someone being able to accomplish carrying someone else up the ladder and getting them through the hatch all in one shot without a rearrangement or a place to stand. |
Obviousman
Member Posts: 405
From: NSW, Australia
Registered: May 2005
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posted May 14, 2011 10:11 AM
Might be of interest to some: I found a document on the NTRS discussing lunar mission safety and rescue scenarios (MSC-03978, dated 15 JUL 71).A torn suit is discussed for lunar orbital operations, but surface ops would be the same: A pressure suit tear poses two potential, difficult rescue situations: (i) a critical drop in suit static pressure, and (2) exhaustion of either or both backpack and emergency oxygen supplies. Even if the EVA crewman is attached to the station oxygen supply by an umbilical, a suit tear could cause a critical and even fatal suit static pressure drop. In this circumstance, the survival time will be a matter of seconds or minutes at best, thus making rescue marginal and escape out of the question.If the suit tear could be repaired or sealed off, survival could probably be extended. Another possibility is to provide a pressure garment or bag which could be unfolded / deployed quickly around the crewman and sealed. The oxygen escaping from the suit tear would fill the garment and thereby provide a satisfactory static pressure level. An exhaust pressure relief valve then could maintain the static pressure and composition within acceptable limits during the rescue operation. Looking through the document, I can't find any reference to one astronaut carrying another except in Table 7-6 (Summary of escape / rescue concepts for lunar surface traverses), where it says that for the walkback concept, a sensitivity to incapacitation is that one crewman must be mobile. Another section later says: A handcart, similar to that used on Apollo 14, should be carried by each lander tug. The handcart should be capable of carrying an incapacitated man either in a pressure suit or a pressurized stretcher. |
Obviousman
Member Posts: 405
From: NSW, Australia
Registered: May 2005
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posted May 14, 2011 10:21 AM
A sister report (MSC-03977) discusses the 'broken bone' case: Effects of Hazard 4, Injury Resulting in Fracture or Flesh WoundInvolvement with the movement, emplacement, and/or erection of large and massive structures or instruments could lead to tip-over or collapse with resultant injuries to crew members involved in setting up these instruments / structures. Fractures or flesh wounds are likely in such events. Although suit rupture in such accidents is also possible, it should be recognized that fractures and bruises could occur without suit damage. Corrective Measures for Hazard 4 Preventive measures:
1. All of the preventive measures recommended for Hazard 3 are applicable.
2. The construction, erection, emplacement, etc, of all proposed lunar structures / instrumentation should be practiced on Earth without omitting any steps (i.e., a complete training program) in order to uncover any difficulties that could arise on the moon and thus correct them before the lunar mission is initiated. Remedial measures:
1. A portable lunar shelter should be available in the event the subject emplacements are distant from the base so that a fellow astronaut can supply first aid in the event of accident. A cabin rover should be very suitable in lieu of a portable lunar shelter. Splints and other first aid items should be included as standard equipment in rovers and other lunar shelters. Escape/Rescue Requirements for Hazard 4
1. If an astronaut is seriously injured he will have to be brought back to the LSB or to the lunar space station or to Earth for treatment of his injuries. |
Lou Chinal
Member Posts: 864
From: Staten Island, NY
Registered: Jun 2007
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posted May 15, 2011 02:46 AM
Paul, getting back to your original question the answer I would quess at is 50-60 moon pounds.Agreeing with just about everybody who chimmed in on this topic - the hatch would be the biggest obstacle to over come. |
moorouge
Member Posts: 1089
From: U.K.
Registered: Jul 2009
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posted May 15, 2011 04:19 AM
The reports make interesting reading. However, the date of publication - July 1971 - makes one wonder why it was left so late into the Apollo programme to consider these matters.Was it the complexity of the 'J' missions that made planners think about it? And were any of the recommendations in the reports implemented, e.g. the containment bag? |
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