Apollo 13

[allancw]

Having just re-watched Ron Howard's Apollo 13, and having consulted with medical people, one question I have: Why didn't the astronauts don their space suits for the three day trip back to earth with no climate control or power in the LEM?

Related issues: Alan Bean has stated that a LEM on the moon with no power (as it was on the powerless LEM returning from the moon, a three day trip under the same conditions) would heat up to 250 degrees f. Yet the Apollo story is that the cabin cooled down to '34 degrees,' according to Lovell. Explain the discrepancy, please.

Assuming that Bean is somehow wrong.... Three days at 34 degrees f would cause severe hypothermia, even death, according to an EMS friend. So how did they survive so well? And again, why not don their spacesuits to stay warm?

The skin of the LEM was 'like two layers of tinfoil.' How do they expect us to believe that whatever the temperature really was (250 f or 34 f) -- with no power would it not be unsurvivable?

[raven]

I've wondered this too actually. Apparently, given the limited water aboard, sweating in the spacesuits would be more dangerous than the hypothermia of being in the rather chill environment.
I am pretty sure it wasn't that cold for the entire trip though
Bean could easily be mistaken.  I know someone here can give the math showing the actual ambient temperature the LM would have. Though I would like a definitive source proven he said this at all.
Also, it's LM, lunar module. While some NASA sources used LEM, the official term past a certain point was LM, lunar module.

[ka9q]

Thermal conditions on the lunar surface are not the same as in deep space, even in the daytime, despite being a hard vacuum in both places.

Objects in vacuum achieve radiative equilibrium with their surroundings. That is, they reach a temperature where the heat power they absorb is exactly equal to the heat power they radiate.

The sun is not the only thing heating a spacecraft. Not only do the earth and moon reflect some of the sun's visible and near-infrared radiation, the sunlight they don't reflect is absorbed, producing heat that is re-radiated in the far infrared. They too reach radiative equilibrium with their surroundings. (A change in the earth's radiative equilibrium is the mechanism behind global warming.)

A LM sitting on the lunar surface is exposed not only to the full force of sunlight but also to a hot lunar surface occupying fully half of the sphere that surrounds it. The lunar surface reaches over +100C at lunar noon, though the Apollo missions were all gone by then.

The LMs were covered with multilayer insulation designed to block as much of this incoming thermal radiation as possible. But keeping heat out also keeps it in, creating a new problem: how to get rid of the waste heat generated internally by electronic equipment and the astronauts' own metabolism. This was done by evaporating water with waste heat much like a "swamp cooler" used in drier locations on earth. Although this consumed precious water, it was a practical solution because the LM only had to operate for a few days at most, and it required relatively little electrical power to drive the coolant pumps. (A regular air conditioner burns most of its power in the compressor that recycles the coolant, but here the water coolant wasn't recycled.)

Battery power was extremely limited in the Apollo 13 LM so its internal systems generated much less internal waste heat than in normal operation. And because it was in deep space, not on the lunar surface, that large external source of heat was missing. It therefore reached thermal equilibrium with its surroundings at a much lower temperature than normal, and that's why it got so cold inside.

[ka9q]

Bean overstated the case a little. The lunar surface does get very hot (over 100C or 212F) at local noon, but all the Apollo crews were gone by then. Temperatures are far more moderate in the local morning, which is when all the landings occurred.

Spacecraft thermal engineering is based on very well understood physical laws, but the computer models are still quite complicated because the environment and spacecraft themselves are so complicated. The spacecraft is represented as a large collection of physical points (or "nodes"), each with a certain thermal mass (specific heat). The nodes have conductive, radiative and perhaps convective connections with each other that have to be evaluated and specified in the model.

The nodes of the external surface are radiatively coupled with the sun, deep space, earth and/or moon in ways that depend on the spacecraft orientation, the positions of those other bodies, and the optical properties of the various surfaces (specifically their darkness at both visible and longwave IR wavelengths). Once you've got this model built you can let the computer turn the crank and solve for the temperature at each node that results in thermal equilibrium. As in computer graphics the basic rules are simple enough but the sheer amount of computation required makes the end result anything but simple.

[Inanimate Carbon Rod]

LEM. Check.

[allancw]

You guys are over my head with some of your data/explanations.... I appreciate the time and effort though. But still, the question remains: Lovell has stated that the temperature in the LM (I stand corrected) quickly dropped to 34 f. This is hypothermia time and sorry but a spacesuit and some sweating would be better than hypothermia (or death, according to my EMS friend).

Bean said as I quoted him in a film (I recall) called Moon Movie. Trust me, I screen-grabbed it. I also found it incredible that Bean didn't know he went through the Van Allen Belt. (You all here should have seen by now his embarrassing interview on this subject.) I compare it to running into someone who claims he climbed Everest and when asked how he handled the thin air answers, 'What thin air?'

I doubt that there are any 'technical' explanations for this one.

I also find it incredible that the Apollo 11 crew claimed they could see no stars from the moon's service and in a BBC interview Armstrong said you cannot see stars from sislunar (sp?) space either -- frankly, you could tell he was lying in this one. It's on Youtube, search 'BBC interviews Neil Armstrong.' You can then go to NASA's 'Pictures of the Day' and see what the day time sky would look like from the earth with no atmosphere (or the moon, same thing). It would be breathtaking.

That an astronaut (all three of the Apollo crew) would lie about this is damning, no?

Also, that they 'lost' 10,000 reel to reel telemetry tapes -- the scientific history of the missions -- makes 'the dog ate my homework' look like gospel. Ditto with the specs to the LM and the Saturn. This sort of thing does it for me.

When I started looking into the possibility that Apollo was a hoax, I totally expected it to be a BS 'conspiracy theory.' I was in for a surprise.

[allancw]

One other thing, and I do appreciate the feedback, even if you guys are on the other side: I'm a professional photographer and the attached photo raises a big red flag. The moonscape is clearly lit from the far left (looking at the photo), whereas for the earth to be 'full', the sun must be behind the camera. In fact, if you look closely, the 'sun' is slightly to the right, the other side.

Two suns?

[Echnaton]

One other thing, and I do appreciate the feedback, even if you guys are on the other side: I'm a professional photographer and the attached photo raises a big red flag. The moonscape is clearly lit from the far left (looking at the photo), whereas for the earth to be 'full', the sun must be behind the camera. In fact, if you look closely, the 'sun' is slightly to the right, the other side.

Two suns?

We are on the other side of what? If you think the missions were faked in some way you must have an alternative theory that better accounts for the evidence. Care to tell us what you think happened.

The photo is lit from the far left?  What exactly does that mean? Care to do the work to show the angle of the lighting?  It is a known photogrammetric  process.  It would also be helpful if you would provide the NASA catalogue number of the actual photo rather than a low res screen capture. 

Think long and hard before you hold yourself out as a professional, there are several people here that can put you to the test on that account. 

[smartcooky]

Lovell has stated that the temperature in the LM (I stand corrected) quickly dropped to 34 f. This is hypothermia time and sorry but a spacesuit and some sweating would be better than hypothermia (or death, according to my EMS friend).

I don't agree with your EMS friend. 34°F is about 1°C. I have spent longer than three days in conditions colder than that in an 11x11 tent on the side of Mt Cook during a military training exercise, with only body heat and warm clothes to stay warm. And I didn't have a space suit either.

You can see from this chart...



...that it is possible for humans to live up to 10 days @ 0°C, which is a degree colder than what the Apollo 13 astronauts had to endure.

NOTE: Chart pinched from here.

http://www.livescience.com/34128-limits-human-survival.html




 

[Echnaton]

Having just re-watched Ron Howard's Apollo 13, and having consulted with medical people, one question I have:

What does the movie have to do with anything?  What medical experts did you consult with?  Do they have any experience as space flight surgeons?  Can you provide any of their analysis? 

[smartcooky]

One other thing, and I do appreciate the feedback, even if you guys are on the other side: I'm a professional photographer and the attached photo raises a big red flag. The moonscape is clearly lit from the far left (looking at the photo), whereas for the earth to be 'full', the sun must be behind the camera. In fact, if you look closely, the 'sun' is slightly to the right, the other side.

Two suns?

That is not a NASA photo, that is from Kaguya, the Japanese Lunar Orbiter. I too am a professional photographer and photo-processor. I see nothing wrong or suspicious about the photo (other than crappy resolution).

How can you say that the photo is lit from the far left when it is clearly lit from about four to five o'clock (six o'clock being directly behind the camera).



NOTE: I found a higher resolution version of your screenshot and have cropped to show the crater shadow below to indicate that its the same photo. The fixed 1:1 circular marquee over the Earth clearly shows that it is gibbous, not full. The terminator is clearly visible on the left side of the disk.

[Chew]

I also found it incredible that Bean didn't know he went through the Van Allen Belt.

The VAB is not some clearly defined zone like a house or a road, where you are either in it or not. The AB is like the Earth's atmosphere: dense at the bottom, less dense the higher you go. All the Apollo missions were designed to avoid the densest section.

(You all here should have seen by now his embarrassing interview on this subject.) I compare it to running into someone who claims he climbed Everest and when asked how he handled the thin air answers, 'What thin air?'

Except no one can sense the VAB. A more apt analogy would be to ask someone if they can feel the difference between 50% and 51% humidity.

I doubt that there are any 'technical' explanations for this one.

The explanations found in reality work really good.

I also find it incredible that the Apollo 11 crew claimed they could see no stars from the moon's service and in a BBC interview Armstrong said you cannot see stars from sislunar (sp?) space either

Watch the complete interview to get the context of the question Armstrong was asked. The interviewer asked him a question about a very specific location and a very specific time.

-- frankly, you could tell he was lying in this one.

Sure, if you already have the preconceived idea he is lying. If you take it at face value he seems genuine.

It's on Youtube, search 'BBC interviews Neil Armstrong.' You can then go to NASA's 'Pictures of the Day' and see what the day time sky would look like from the earth with no atmosphere (or the moon, same thing). It would be breathtaking.

Try standing directly under a bright streetlight and look straight up. Tell us how many stars you see.

That an astronaut (all three of the Apollo crew) would lie about this is damning, no?

Sure, if they were lying. But they're not.

Also, that they 'lost' 10,000 reel to reel telemetry tapes -- the scientific history of the missions -- makes 'the dog ate my homework' look like gospel.

Do you know the complete history of that story? It seems you don't.

Ditto with the specs to the LM and the Saturn.

Right out of the hoax believer playbook. Now go do some real research and find out how you've been lied to.

This sort of thing does it for me.

When I started looking into the possibility that Apollo was a hoax, I totally expected it to be a BS 'conspiracy theory.' I was in for a surprise.

No, you believed it was a conspiracy before you "started looking" into it.

I think this falls under the "just asking questions" so mark your box if you have it.

[allancw]

Yes, slightly gibbous but you're hoisting by your own petard since the sun is then to the right of camera, with the moonscape lit from the left... the dark shadow band at the bottom clearly should be sun-lit.

[gillianren]

Your Shakespeare is wrong, too.  The expression is "hoist by your own petard" and roughly means "blown up by your own hand grenade." 

[Chew]

the dark shadow band at the bottom clearly should be sun-lit.

Huh? The bottom is lit. Look at the shadow made by the peak in the crater. The sun is obvious to the right.