[alangibson]

It seems straightforward to you because you're ignoring everything that makes this not work.

Here's a big one: you can't put radiators in shadow because the coolant would freeze. ISS has system dedicated to making sure the radiators get just enough sunlight at any given time.

[DoctorOetker]

The ISS goes into Earth's shadow for ~45 minutes and then in the sun for 45 minutes, in 24/7 repeat;

this system would not be given such an orbit. Its trivial to decrease the cooling capacity of the radiators: just have an emissivity ~0 shade (say an aluminum foil) curtain obscure part of the radiator so that it locally sees itself instead of cold empty space. This would only happen during 2 short periods in the year.

The design issues of the ISS are totally different from this system.