[mike_hearn]

You can just use ordinary radiators. Do the calculations, cooling isn't the problem it's made out to be.

[abirch]

It's the size of the radiators and the expense of getting them up into orbit (along with maintenance)

Most of my assumptions come from discussions like: https://news.ycombinator.com/item?id=46876105

[sokka_h2otribe]

(1) these are not ordinary radiators because ordinary radiators aren't gold plated and don't unfold dramatically from compact shipping sizes (2) It's absolutely loads of radiators