section_path: Use in space
section_name: Use in space
paragraph_text: Use in space
  
  The most common use of nuclear power in space is the use of radioisotope thermoelectric generators, which use radioactive decay to generate power. These power generators are relatively small scale (few kW), and they are mostly used to power space missions and experiments for long periods where solar power is not available in sufficient quantity, such as in the Voyager 2 space probe. A few space vehicles have been launched using nuclear reactors: 34 reactors belong to the Soviet RORSAT series and one was the American SNAP-10A.
  
  Both fission and fusion appear promising for space propulsion applications, generating higher mission velocities with less reaction mass.