Temperature System How and why do we control heat on a spacecraft?

What is heat?

This is one of those questions that is simple and complex at the same time. Everyone has felt heat, but what is it?

The simple answer is that heat is energy.

Heat travels in waves like other forms of energy, and can change the matter it touches. It can heat it up-which starts molecules moving or it can cause chemical reactions like burning to occur.

Heat can be released through a chemical reaction (such as the nuclear reactions that make the Sun "burn") or can be trapped for a limited time by insulators. It is often released along with other kinds of energy such as light, radio waves, or sound waves. A burning candle releases light and heat waves; an explosion releases light, heat, and sound waves. The Sun releases all kinds of energy waves.

Why do we have to control heat on a spacecraft if there are no people on board?
How does heat move?
How and why do we control heat on a spacecraft?
What is energy?
Is there energy in space?

What are heat sinks in DS1?
What are heat sources in DS1?
Does heat travel differently in space than it does on Earth?
Will DS1 get heated directly by the Sun?
What role does the Sun play in space missions like DS1's?

What other forms of energy does a spacecraft releases into space?
What happens to the heat once it is released into space?
What makes EM radiation?
Why does electrical current make heat?
Where does energy come from and go?