Cooling Server Satellites
Server satellites are heated by the sun and by power dissipation, and cooled by black body radiation.
For a uniform source surrounded by a uniform radiation heat sink, black body heat radiation power is proportional to the emissivity multiplied by the difference between the temperatures of source and sink to the fourth power:
P = ~ \epsilon ~ \sigma ~ ( T_{source}^4 - T_{sink}^4 )
P == Power flow (W)
\epsilon == emissivity ( 0.0 = white/shiny, 1.0 = black )
\sigma == Stefan-Boltzmann black body constant, = 5.67 × 10−8 W m−2 K−4
The server-sat heat sink is not uniform - the sun is very hot (and visually small), the 250K earth fills a quarter of the sky (at m288), and deep space is 2.7K (effectively zero).