When it left earth the telescope was too warm to do it’s job, and the only way to get rid of heat in space is to radiate it away. There’s no convection, no cool breezes (ha!), etc., and radiating heat away is comparatively slow. As far as the ambient temperature of deep interstellar space, I always thought it was just a few degrees above absolute zero. But this close to the sun, it’s another story.
That’s just what I think. I could definitely be wrong about all this. Someone correct me if I am, thx!
Well, it looks as though you are right. Space is cold but near gas giants is very hot.
I remember reading space was in the 70 degrees, though. I guess that was an old article when they didn’t know better, many years ago? Or I dreamt that whole thing up, lol.
https://www.accuweather.com/en/space-news/what-is-the-temperature-in-space-and-why/686238