I was amused to read recently that the US military plans to send nuclear reactors into space, as if space is not already pretty full of nuclear reactors. Unfortunately, neither the US military nor anyone else on Earth has yet worked out how to harness nuclear fusion – the process that powers the sun and all the other stars. The only human use of fusion is in thermonuclear weapons. This more modest plan involves sending ordinary fission reactors into space.
Nuclear propulsion systems are the preferred choice for future space exploration missions. They are much more efficient than traditional chemical propulsion systems and offer higher thrust than sustainable alternatives such as solar energy.