Temperature System

How and why do we control heat on a spacecraft?

What happens to heat once it is released into space?

Heat is released as electromagnetic radiation or, in other words, infared waves. All objects generate electromagnetic radiation. The radiation generated by an object basically depends on its temperature. Warm objects, such as yourself, generate far infared radiation. Far infared means that infared radiation that is far away from the visible light side and near the microwave side.

However, if you really heat an object up to several hundred degrees, it the starts to generate near infared radiation. If you continue heating the object then you will get the following visible light colors in sequence:

And if you still continue heating, most of the energy released will then drift into the ultraviolet region.

Object Temperature Radiation generated
human body 100F far infared
really hot oven 700F

near infared

electric stove burner 1000F dull cherry glow (light)
candle 1500F bright orange glow (light)
light bulb (filament inside) 3000F white light
oxygen/hydrogen flame 6000F bluish white
  10,000F+ near ultraviolet

All radiation which leaves the spacecraft eventually becomes part of what is known to astronomers as the background radiation constant. The background radiation constant is average amount of radiation that the universe holds. The background radiation constant can also be seen as the average temperature of the universe. This means that all radiation released eventually becomes part of the background warmth of the universe.

Why do we have to control heat on a spacecraft if there are no people on board?
How is DS1's heat balance maintained?
What is heat?
How does heat move?

What is a heat sink?
How do active heat sinks work?
Does heat travel differently in space than it does on Earth?

What makes EM radiation?
Where does energy come from and go?
What other forms of energy does a spacecraft releases into space?