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Post by PhantomWolf on Aug 22, 2005 5:33:52 GMT -4
Having just watched the 1995 British Museum DVD The Apollo Story, narrated by Sir Patrick Moore, I noted that he stated that is Apollo 13's accident had occured on the way back from the moon then the crew would have been doomed because they would have already jetisoned Aquarius. This got me wondering as to if this would have been true, or if it would have depended on where in the journey home. Could the crew have lasted in Odyssey long enough to get home, or would they have run out of air? Assuming that they coulkd have, could they have made their re-entry withough the use of the Service module in any way? Is there anyway that they could have made it, or as he stated, would they have been doomed?
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Post by Count Zero on Aug 22, 2005 6:08:01 GMT -4
Offhand, I think the killer (literally) would have been power. The explosion and subsequent oxygen loss took-out the fuel cells on the SM. The CM only had a couple of hours of battery life. On the return, they would not need to maneuver much (unless the venting pushed them off-course). If they could've diagnosed the problem quickly and shut everything down, they might have made it, on the other hand, maybe just the juice needed for the radio would have been too much of drain. Also, did they need power to push air through the lithium hydroxide canisters? The situation would have been very, very desperate.
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Post by gwiz on Aug 22, 2005 6:14:34 GMT -4
I agree, power to run the guidance computer and inertial platform too, otherwise they couldn't control the re-entry trajectory.
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Al Johnston
"Cheer up!" they said, "It could be worse!" So I did, and it was.
Posts: 1,453
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Post by Al Johnston on Aug 22, 2005 7:12:05 GMT -4
I think they would have needed power to move the air around full stop: on Earth it would circulate by convection currents, but you don't get those in freefall. Otherwise the astronauts would have had to move around to avoid building up their own individual bubbles of depleted air.
Of course if it had been judged that desperate, one astronaut could have been given the job of fanning his hands over an open LiOH canister...
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Post by echnaton on Aug 22, 2005 9:19:46 GMT -4
If the explosion would have occurred during LM decent it would likely have meant that there could have been no recovery. At some point during decent, the decent stage contained too little fuel to get back to the CSM and would have to be jettisoned for the astronauts to return to orbit. Without the decent stage there would have been insufficient electrical power in the LM asset stage to keep the it functional for a trip home. Further they would have been forced to use the CSM engine to the TEI burn, consuming precious battery power needed for reentry. Pushing further back into the mission I imagine that if the explosion occurred any time after the LOI burn, a safe return would have been problematic from even a theoretical perspective.
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Post by stutefish on Feb 22, 2006 17:26:57 GMT -4
This kind of reminds me of the HB claim that the missions couldn't have happened, on account of the Saturn V needing weeks of prep and a crew of thousands while we're expected to believe that the AM could achieve similar results with a tiny fraction of the support infrastructure.
The answer, of course, is manifold. One of the key factors is that both the Saturn V and the Apollo AM were designed with the available resources in mind.
The guys who solved the Apollo 13 problem solved the problem in front of them using the resources available to them.
And their solution was pretty unpredictable and even a little "crazy". It certainly wasn't something anybody had forseen or planned for.
I'd like to think that if the Apollo 13 problem had been different in nature, the solution would also have been different in nature. Obviously, there would have been a point of no return somewhere along the way, but I'm not sure the limitations of the solution they went with would have much bearing on problems they didn't actually have.
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Post by maelin on Feb 22, 2006 21:26:46 GMT -4
I concur with stutefish here. The three astronauts on Apollo 13 and all the engineers and mission planners and other NASA guys back on Earth solved the problem through (often ingenious) use of whatever they had available to them. As it turned out, their expertise and creativity, combined with the resources available, were sufficient to solve the problem. When you change the problem and the resources, then obviously the -same- solution wouldn't work. But there's no real way to tell whether the expertise and creativity would have been sufficient to solve that different problem.
It's not really possible to go hypothetically back in time and change the circumstances of events and then try to work out with any degree of certainty what the results would be. You can hypothesise what might have occurred, and people do this all the time in alternate history fiction (a popular one is "What if Hitler won the war?") but you can never really know for sure.
Don't let me stop you hypothesising, though, just remember you can never really be certain about the results of an alternate past event. At least not with as many unknown variables as Apollo 13 had.
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Post by Jason Thompson on Feb 23, 2006 5:26:32 GMT -4
I don't think they could have made it had the accident happened any time after LM jettison. The explosion caused the CSM to lose its entire oxygen supply except for the surge tank that was isolated in the CM. The surge tank was to last for a few hours only since it was only to be used for re-entry once the service module had been jettisoned. After the accident the crew used the oxygen supply of the LM simply because there was no other oxygen supply for them to use.
Whatever power saving measures mission control and the astronauts could improvise, they couldn't avoid the fact that with all the oxygen in the SM having vented into space and the surge tank in the CM only supplying a few hours of oxygen they'd all have suffocated long before re-entry.
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Post by thestargazer on Feb 23, 2006 9:37:48 GMT -4
This puts me in the mind of a statement I recall hearing from one of the Apollo-13 crewmen (and honestly I can't recall who it was) who said that, had a return attempt been unsuccessful that there was (and this isn't a direct quote, mind) "a vent that we could open" to release the remaining air supply in the cabin. Basically a suicide option.
Yet in the intervening years I've heard Jim Lovell state that literally right up to the last second of life they had they'd be fighting to get back safely.
I'd like to think I'm misremembering that first statement and that the second one is the more accurate but can anyone lend any insight...?
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Al Johnston
"Cheer up!" they said, "It could be worse!" So I did, and it was.
Posts: 1,453
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Post by Al Johnston on Feb 23, 2006 12:44:01 GMT -4
I suspect that knowing their craft as well as they did, they would each be conscious of several "suicide options", while still doing their damnedest to get themselves and their ship back home.
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Post by dwight on Feb 23, 2006 16:19:10 GMT -4
Just curious, say they miscalculated the reentry coords, was there any possibility of a "Marooned" style rescue? For example could a Saturn 1B be readied in time to do a possible CSM -> CSM transfer?
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Post by Jason Thompson on Feb 23, 2006 18:23:11 GMT -4
This puts me in the mind of a statement I recall hearing from one of the Apollo-13 crewmen (and honestly I can't recall who it was) who said that, had a return attempt been unsuccessful that there was (and this isn't a direct quote, mind) "a vent that we could open" to release the remaining air supply in the cabin. Basically a suicide option.
This sounds like a misremembered response to the question of suicide pills. It may have been Jim Lovell who was asked, but apparently a journalist asked if the astronauts had suicide pills to take in case of a definite non-survivable scenario. The astronaut pointed out that they would never give up anyway, but in any case suicide pills wouldn't be necessary, since you could easily kill yourself in any one of a dozen ways when you're in a spaceship, most easily by venting the oxygen.
Which puts me in mind of a story I heard about a journalist who was flummoxed by Buzz Aldrin. Apparently, and I don't know how true the story is, Aldrin was asked what he would spend his last hours doing if the LM ascent engine failed to ignite after the EVA. One might reasonably assume that the journalist was looking for something along the lines of 'I'd pray, make peace with myself and just wait for the end in the glorious knowledge that we died trying to expand Man's horizons.' What he got was:
'I'd be trying to get the engine working!'
Just curious, say they miscalculated the reentry coords, was there any possibility of a "Marooned" style rescue? For example could a Saturn 1B be readied in time to do a possible CSM -> CSM transfer?
Even if it could, the two CSMs would be travelling in opposite directions at great speed. By the time the returning CSM gets near enough to realise that the re-entry has been miscalculated it is travelling at near 25,000mph. There is no possibility of slowing it down because there would be insufficient fuel to do so. It would then either shoot on past in which case it will certainly not return before the oxygen runs out, or it will burn up in the atmosphere. Even assuming you could calculate the orbit of a new CSM to meet it as it made its nearest approach, the second CSM would only be doing about 17,500mph (orbital velocity). No-one in their right minds is going to try and rendezvous with an object moving at 7,500mph relative to them!
The only way I can see of doing a CSM-to-CSM rescue is in lunar orbit, because that's the only time when both vehicles could be travelling in the same direction at near-enough the same speed to allow for rendezvous. By the time the craft is approaching the Moon you'd be hard-pressed to catch up with it (I don't think even launching a Saturn V with only a CSM equipped with the minimal supplies needed to affect a rescue could blast that CSM out of Earth orbit with enough oomph to catch a vehicle with a day or two head start), and when it's coming back it is constantly accelerating towards you: not an ideal rendezvous situation.
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Bob B.
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Post by Bob B. on Feb 23, 2006 18:36:54 GMT -4
Just curious, say they miscalculated the reentry coords, was there any possibility of a "Marooned" style rescue? For example could a Saturn 1B be readied in time to do a possible CSM -> CSM transfer? If the reentry was miscalculated the spacecraft would either come in too steep, in which it would burn up in the atmosphere, or too shallow, in which it would skip back out into space. In the first case the crew would obviously be dead. In the second case the spacecraft would still be in an Earth orbit, since it was traveling below escape velocity, but it would be in a long elliptical orbit that would take it far out into space before returning to Earth. It would probably be several days before the craft would return, by which time the consumables would be gone and the crew dead. Furthermore, a rescue using a Saturn 1B would be impossible because the stricken spacecraft would swing by Earth at such high velocity that a rescue mission wouldn't be able to catch up with it.
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Bob B.
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Post by Bob B. on Feb 23, 2006 18:56:28 GMT -4
Jason,
A lunar orbit rescue is one possibility. The only other scenario I see as a possibility is to put a CSM in orbit on a Saturn V and then wait for the damaged spacecraft to swing by Earth. As it approaches perigee, the rescue craft would perform an S-IVB burn and the two ships would rendezvous close to Earth at 25,000 mph. After the crew transfers to the good spacecraft, they'd have to either wait while the ship completes its long orbit, or a second burn big burn would have to be performed to abort and come straight back to Earth.
In either rescue mode a Saturn V launch would be necessary, which simply isn't possible on such short notice. A Saturn 1B would be inadequate for the task.
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Post by Fnord Fred on Feb 24, 2006 16:46:27 GMT -4
Wouldn't they be short on space too? I'm guessing that the rescue craft would need at least one and probably have at least two crewmen to do the rendevous. Did we have a vehicle that could take 4-5 people through reentry? Did the CM even have a proper airlock for spacewalks? I was under the impression that they could only leave the CM by either the hatch (e.g. when they landed in the ocean) or through the LM.
Also, didn't they only have two suits? Would they have to leave someone behind?
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