The thing is, though, to cool something in an airless environment you just put up some sunshades and suddenly everything is a ridiculous -100 C or so. No convec

The thing is, though, to cool something in an airless environment you just put up some sunshades and suddenly everything is a ridiculous -100 C or so. No convective or conductive heat transfer to speak of, so it's entirely radiative, which means a couple layers of tinfoil reduce it to functionally zero. Assuming your tinfoil doesn't melt, of course.