How and why do we control heat on a spacecraft?

NASA scientists use a variety of devices to create heat, trap heat, and release heat into space. They do this so that the spacecraft runs at optimal efficiency and no parts become too warm or too cold.

Ask any question below to learn about how and why we control heat on a spacecraft.

Why do we have to control heat on a spacecraft if there are no people on board?
What could go wrong on DS1 if there's too much heat?
How is DS1's heat balance maintained?

What is stress?
Why does heat make the electrical system less efficient?
What is heat balance?
What is a heat source?
What is a heat sink?
How do active heat sinks work?
How do passive heat sinks work?
Why does the ship's orientation matter?

What other forms of energy does a spacecraft releases into space?
Why does electrical current make heat?
What's a resistor?
What happens to heat once it is released into space?
How could expanding gas cause heat loss?