NASA’s Space Nuclear Propulsion (SNP) Office aims to revolutionize space travel by developing and demonstrating higher performance propulsion systems to achieve the agency’s ambitious science and exploration goals. Within this effort, NASA is exploring two propulsion systems – nuclear thermal and nuclear electric – each providing unique and complementary capabilities.

Nuclear thermal propulsion provides high thrust at twice the propellant efficiency of chemical rockets, freeing up weight and mass for payload and mission-essential supplies aboard the spacecraft. Heat is generated in the fission reactor and directly transferred to a flowing liquid propellant turning it into a gas, which is then expanded and exhausted through a nozzle to propel a spacecraft.

Nuclear electric propulsion uses heat from the fission reactor to generate electricity, much like nuclear power plants on the Earth. That electricity is then used to ionize a gaseous propellant and electromagnetically accelerate it, generating thrust that propels a spacecraft.

Developing advanced space nuclear propulsion systems is key to NASA’s Moon to Mars vision. It will allow for more rapid transits to destinations from the Moon to Mars and across the outer solar system. Nuclear propulsion systems can also provide much higher power for onboard instruments and communication systems, which can be especially beneficial as the spacecraft travels farther from the Sun where the ability to harness solar power becomes impractical.

• NASA’s space nuclear propulsion project is led by the agency’s Space Technology Mission Directorate and funded through its Technology Demonstration Missions program based at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The project, also at Marshall, collaborates with DOE to advance the key technologies needed for future human missions to Mars.
• DOE facilities supporting NASA’s space nuclear propulsion project include Idaho National Laboratory, Oak Ridge National Laboratory, and Los Alamos National Laboratory.
• In addition to Marshall, NASA centers supporting nuclear thermal propulsion activities include NASA’s Glenn Research Center in Cleveland and NASA’s Stennis Space Center in Mississippi. 
• Nuclear thermal propulsion development is also supported by the Massachusetts Institute of Technology, University of Alabama Huntsville, Aerojet Rocketdyne, BWX Technologies, UltraSafe Nuclear Corporation, the Aerospace Corporation, Analytical Mechanics Associates, and Geocent.
• Each supporting entity brings its own unique expertise and capabilities to contribute to the goal of realizing a high-performance fission-based propulsion system to enable extended human exploration of the solar system.