In close proximity, and connected to metal structures radiating & conducting heat at 120 degrees. You still have to expel that heat somehow, and route it around the spacecraft core.
>>adastr+(OP)
I think stopping the heat conductivity is a solved problem - space telescopes manage to do this. But all in all, cooling in space remains a very big challenge.
>>Tepix+gF
No, it isn’t solved. The James Webb telescope was shipped with cryogenic coolant, and put in an orbit in the shadow of the moon far from the radiating earth. Once it runs out in a few years, it’s done.