NASA plans to send crewed missions to Mars over the next decade—but the 140 million-mile (225 million-kilometer) journey to the red planet could take several months to years round trip.
This relatively long transit time is a result of the use of traditional chemical rocket fuel. An alternative technology to the chemically propelled rockets the agency develops now is called nuclear thermal propulsion, which uses nuclear fission and could one day power a rocket that makes the trip in just half the time.
Nuclear fission involves harvesting the incredible amount of energy released when an atom is split by a neutron. This reaction is known as a fission reaction. Fission technology is well established in power generation and nuclear-powered submarines, and its application to drive or power a rocket could one day give NASA a faster, more powerful alternative to chemically driven rockets.
NASA and the Defense Advanced Research Projects Agency are jointly developing NTP technology. They plan to deploy and demonstrate the capabilities of a prototype system in space in 2027—potentially making it one of the first of its kind to be built and operated by the US.