Gaseous fission reactor

Gaseous fission reactors are a hypothetical type of nuclear reactor proposed for use in space travel. One limitation on the specific impulse of conventional fission reactions in nuclear thermal rockets is that if the temperature is too high the reactor core melts. The solution is to create a reactor whose core is gaseous. This can create specific impulses of 20,000 s which is good enough for fast interplanetary travel.

See also: spacecraft propulsion