Nuclear Thermal Propulsion

Nuclear thermal propulsion uses a nuclear reactor to heat propellant directly and exhaust it through a nozzle. The nuclear reactor core is the hottest element in the engine and limits the effectiveness of the drive.

Nuclear thermal engines allow for shorter transit times and/or lower propellant requirements than chemical engines. They are usually planed for orbital operations only, and are in completion with alternative technologies such as Nuclear Electric Propulsion (NEP) and Solar Electric Propulsion (SEP).