Space isn’t cold, it’s nothing. It’s a vacuum and vacuum is terrible at heat transfer by convection. It’s why thermos bottles have a vacuum layer to prevent heat transfer. You can try to lose some heat by radiant cooling, but that’s slow and if you’re using solar for power then any radiators become heat sinks picking up more heat from the sun. Then there’s conduction, and again, there’s really nowhere to conduct any heat to, what with the large distance between objects and the vacuum and all. Thermal management in space is kind of a hard problem.
If it was impossible to remove heat from things in space we wouldn’t have spacecraft or satellites. We wouldn’t have a permanently manned research outpost in orbit. Hell, the Earth would probably be a big molten ball of lava. But we can effectively remove heat from an in-vacuum system that produces its own heat, all you need are radiators. If it’s radiating too slowly, you get a bigger radiator.
I didn’t say it was impossible, I said it was hard. Bigger radiators absorb more heat when exposed to the sun. One of the problems becomes keeping the solar panels exposed to sunlight while keeping the radiators out of it. Putting them behind the solar panels might work, but they have to be smaller than the solar panels and any energy the solar panels don’t convert to electricity will be re-radiated as heat and picked up by the radiators, requiring a larger size. You could put them on the 'back" side of the spacecraft, but that limits the size. As mentioned in another comment, you could position the spacecraft in geostationary orbit on the terminator, but then reaction mass requirements for station keeping and data signal latency go way up. It’s a problem that has been worked around by people much smarter than me, but a lot of work went into figuring it out.
Space isn’t cold, it’s nothing. It’s a vacuum and vacuum is terrible at heat transfer by convection. It’s why thermos bottles have a vacuum layer to prevent heat transfer. You can try to lose some heat by radiant cooling, but that’s slow and if you’re using solar for power then any radiators become heat sinks picking up more heat from the sun. Then there’s conduction, and again, there’s really nowhere to conduct any heat to, what with the large distance between objects and the vacuum and all. Thermal management in space is kind of a hard problem.
Makes sense. Thanks for the insight!
If it was impossible to remove heat from things in space we wouldn’t have spacecraft or satellites. We wouldn’t have a permanently manned research outpost in orbit. Hell, the Earth would probably be a big molten ball of lava. But we can effectively remove heat from an in-vacuum system that produces its own heat, all you need are radiators. If it’s radiating too slowly, you get a bigger radiator.
I didn’t say it was impossible, I said it was hard. Bigger radiators absorb more heat when exposed to the sun. One of the problems becomes keeping the solar panels exposed to sunlight while keeping the radiators out of it. Putting them behind the solar panels might work, but they have to be smaller than the solar panels and any energy the solar panels don’t convert to electricity will be re-radiated as heat and picked up by the radiators, requiring a larger size. You could put them on the 'back" side of the spacecraft, but that limits the size. As mentioned in another comment, you could position the spacecraft in geostationary orbit on the terminator, but then reaction mass requirements for station keeping and data signal latency go way up. It’s a problem that has been worked around by people much smarter than me, but a lot of work went into figuring it out.