NASA Plans First Nuclear-Powered Interplanetary Mission to Mars in 2028
NASA announces the development of Space Reactor-1 Freedom, the first nuclear-powered interplanetary spacecraft, set to launch in December 2028 to deploy helicopters on Mars.
NASA has announced the development of Space Reactor-1 (SR-1) Freedom, the agency's first nuclear-powered interplanetary spacecraft, with a planned launch in December 2028. The mission aims to deploy a fleet of three aerial helicopters, known as the Skyfall payload, to scout Mars for future human exploration sites and map subsurface water ice deposits.
SR-1 Freedom will utilize a nuclear electric propulsion (NEP) system, marking a significant advancement over traditional propulsion methods. Unlike radioisotope thermoelectric generators (RTGs) that have powered previous missions by converting heat from radioactive decay into electricity, NEP systems employ an onboard fission reactor to generate electricity, which then powers high-efficiency electric thrusters. This approach offers enhanced efficiency and the capability to operate at all distances from the sun.
The spacecraft's design incorporates a 20-kilowatt fission reactor fueled by high-assay low-enriched uranium (HALEU) and uranium dioxide, encased in a boron carbide radiation shield. For propulsion, SR-1 Freedom is equipped with four 6-kilowatt Hall-effect thrusters built by Busek and three 12-kilowatt Advanced Electric Propulsion System Hall-effect thrusters developed by NASA and Aerojet Rocketdyne.
The Skyfall helicopters, developed by NASA's Jet Propulsion Laboratory in partnership with AeroVironment, build upon the success of the Ingenuity rotorcraft, which completed 72 flights on Mars. These new helicopters are designed to conduct critical missions, including scouting landing zones, identifying terrain hazards, and mapping water ice deposits using cameras and ground-penetrating radar.
NASA emphasizes that SR-1 Freedom will not only support the Mars mission but also establish flight-heritage nuclear hardware, set regulatory and launch precedents, and activate the industrial base for future fission power systems across propulsion, surface, and long-duration missions.
This mission represents a collaborative effort between NASA and the United States Department of Energy, aiming to demonstrate nuclear propulsion and power technologies for sustained exploration beyond the Moon, including future missions to Mars and the outer Solar System. Data from SR-1 Freedom is also expected to support the development of Lunar Reactor-1 (LR-1), a fission surface power system designed to provide continuous energy for a lunar base during periods without sunlight.