Blackbody radiation is very counter intuitive
Quite.
...as one explores EM radiation further (Maxwell) it really is not a simple problem. The physics of EM waves (and low energy electrons) interacting with electrons in metals is very involved.
Indeed, the notion that metals are the best conductors of heat and the best conductors of electricity for special electron reasons is kind of fascinating.
There have been lots of claims pertaining to 'it would get too hot!' My memory is hazy, but I recall a discussion about infrared absorption by the Apollo space craft, and how this depended on wavelength and the angle of the incident radiation. In which case we have a calculus problem. Funny how lots of engineering ends up with calculus.
I remember some idiot claiming that physics was basically just applied calculus when what he should have said was that engineering is basically just applied calculus. But yes, we have mathematical formalisms and some hacky approximations to reason about "view factors." And yes, this was actually simulated on a computer for the LM, using a predictably small number of modeled surfaces. To my knowledge it was the first use of computational radiometry in space engineering.
Again memory is hazy; but did the Apollo craft need to rotate in space for reasons of temperature control, and did the astronauts complain that the LM was becoming too cold on the lunar surface?
Both true. Passive thermal control in the CSM is mostly about reducing thermally induced stress in the assembly—a purely engineering problem. When you build something and you let half of it get very hot and the other half get very cold, you run into all kinds of problems and stresses. One answer is to rotate the stack at a rate best calculated to even out the temperature. For spacecraft like geostationary communication satellites, there are active systems that move heat around, since those spacecraft have pointing constraints inherent to their mission and can't be slow-roasted by rotation. The CMs that were docked to Skylab for a long period were actually painted white (i.e., with a different passive thermal control strategy) since they couldn't rotate either.
The LM had a peculiar problem in that the mass distribution for pitch stability put a lot of equipment in the back and the cockpit in the front. The plan was always to land with the sun at the crew's backs so that the spacecraft shadow could be a visual cue for the pilot. But this means that all that bulky equipment is the part of the ship taking the direct sunlight, and the cabin is on the shady side of the ship.
Part of the qualification for new spacecraft designs is vacuum roasting. You put the spacecraft in a vacuum chamber with massive radiant heaters on the walls. You then selectively roast the spacecraft on one side or the other to see what happens.
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