In other news
Airbus have come up with a new moniker for the 737, the Splatoliner.
You need to cool - or rather moderate the temperature of electronics and other equipment in space because of massive temperature swings between sunlit and unlit areas.
If your rad hardened but otherwise clapped out PowerPC chip is happy running at 75°c then you need a temperature control system that can deal with the swings of temperature and keep it at that point, which also needs to be fast reacting (some things in here don't react well to icing) so with extra capacity for the quick changes between heating and cooling.
If something is always going to be in the lee of a planetary body you just need heaters - ditto if you are sending it to the outer planets - but even then it's sensible to fit some degree of cooling - in case of unforeseen circumstances.