Shuttlepod One and Cooling

[Sonnenburg]

Saw Apollo 13 again the other day and was reminded of this episode. In this one, Tucker and Reed are stranded with limited oxygen in a flying Yugo (everything in the pod is breaking). With oxygen tanks punctured, we get the following exchange:

TUCKER: Would another half day be worth freezing your butt off?
REED: What are you talking about?
TUCKER: If we lower the thermostat in here to about minus-five centigrade, we should be able to use that power to enhance the efficiency of the atmosphere recyclers.
REED: Our last two and a half days freezing versus our last two days toasty warm.

Given the facts that radiating heat in space isn't very efficient, that machinery actually generates heat (unlike Apollo 13, they didn't shut anything off except, apparently, the heater), and that a shuttlepod -even with a spot with an emergency patch in it- would probably be better insulated than the LEM-command module was in that movie, am I right in thinking there was no reason for it to get that cold that fast? Or am I missing something?

[tim31]

It was in physical contact with a comet? Does that change the situation at all? Probably not(still a vacuum), but it's all I've got.

[open_sketchbook]

Don't Star Trek vessels radiate heat into subspace? It might be that overly efficient cooling mechanisms were their own downfall as the temperature bled out while at impulse. If they displace mass into subspace to accelerate faster, they might actually lose more heat into subspace the more mass they displace. The shuttlepod was going full-tilt, if you'll remember, so it may be that breached systems + subspace mass displacement lead to their rapid temperature drop.

[Ted C]

Given the facts that radiating heat in space isn't very efficient, that machinery actually generates heat (unlike Apollo 13, they didn't shut anything off except, apparently, the heater), and that a shuttlepod -even with a spot with an emergency patch in it- would probably be better insulated than the LEM-command module was in that movie, am I right in thinking there was no reason for it to get that cold that fast? Or am I missing something?

Since there's no way for an object in space to shed heat by conduction or convection, it's my understanding that spacecraft generally have more of a problem with overheating than freezing.

[Bounty]

Overactive radiators perhaps? If it's not losing heat naturally it has to be actively cooled, so perhaps the cooling system was designed to just keep going and leave the precise temperature controls to the internal heater. It's a clumsy system, but hey, a Yugo...

[Junghalli]

I'm not sure if Apollo 13 is really the best comparison. Apollo 13 was moving around at Earth's distance from the sun and, except for periods when it was in the Moon or Earth's shadow, would have been getting plenty of sunlight. If this shuttlepod is somewhere in the outer system it would have been getting almost no heat from its external environment; the only sources of heat would have been the body heat of the crew and waste heat of the machinery, and assuming those weren't enough to raise the internal temperature by many degrees C by themselves the shuttle would have gradually begun to become uncomfortably and then unsurvivably cold without deliberate heating.

Perhaps the shuttle's hull material is a very lousy insulator. Given that spacecraft often have the opposite problem (too much heat) it might have been deliberately designed to conduct excess heat out of the cabin as quickly as possible. As has also been touched on, if it was touching the ground heat might have been conducted into the (presumably very cold) ground, which might also cause rapid heat loss.

[Sonnenburg]

They are definitely in a solar system (not sure how far) but not inside of touching any object. Also, the way they describe it, there's actually something apparently responsible just for heating the cabin, because they save power by turning down the thermostat. In other words, it's not waste heat warming the cabin, it's an actual heater.

And thinking on it more, given that these are meant to be the primary means of going to planets, wouldn't they be designed to have as much insulation around the cabin as possible? This is pre-shields, after all, so it's nothing but hull to deal with a possibly very-fast re-entry?

[Junghalli]

Inside a solar system still leaves the possibility that they're somewhere around, say, Saturn orbit, where the amount of heat they'd get from the sun would be way too little to maintain a survivable environment for humans. It's not much of a stretch to think you might need a heater to maintain survivable temperatures in such an environment.

The Apollo 13 did become very cold when they switched off most of their electronic equipment (link), it doesn't seem like much of a stretch to me to think something similar may have been happening with the shuttle.

[Sonnenburg]

But they took mere hours to reach the temperature Apollo 13 reached at the end of three days, in a ship with everything running compared to one that was powered down. Even if it was out that far, would being on a ship with all those advantages plus the likelihood of a more insulating hull mean they were more likely to last at least as long as the Apollo 13?

[Mr Bean]

But they took mere hours to reach the temperature Apollo 13 reached at the end of three days, in a ship with everything running compared to one that was powered down. Even if it was out that far, would being on a ship with all those advantages plus the likelihood of a more insulating hull mean they were more likely to last at least as long as the Apollo 13?

Without know more about the design we can't say. Maybe they suffer from too GOOD of an engineering issue to the point at which their shuttles equipment by design produces very little waste heat.

Look at it this way in any spacecraft producing heat is bad because it's hard to dump waste head. So lets say they have enough solid state superconducting lower temperature equipment that aside from the possible subspace using engines their comms, the environmental and refresher units produce little heat as does navigation their smug generator.

If you could engineer to that point that all the systems produce little heat then you might indeed run into a situation where you need to add a heater to produce heat thanks to some kickass design and engineering work. Except that heating this is the easiest thing to do, all you need is power and you can heat anything anywhere. Heck those old fashion bare metal home heaters which is nothing more than a heater element backed by a heat reflective surface use very little power as the "waste heat" in this system is what your trying for to begin with.

In Summary
Yes they should in fact survive longer than the Apollo 13 Astronauts could have. Even if their shuttle was almost totally unshielded, even if they were in the middle of deep space with minimal positive heat gain from the sun and no waste heat being produced by the shuttles electronics, they should have run out of air long before they ran out of heat.

Heck they could have gone a long way with that joke by having them alternating baking and wheezing with the heat on and the air off, or breathing and shivering with the heat off and the air on. Regardless, even an unshielded shuttle should be able to keep heat in for more than twelve hours.