Nuclear energy technology uses heat from fissile materials to produce electric power
Nasa has announced it is seeking proposals for five technological areas, including radioisotope power systems, to support exploration missions with a near-term focus on a base at the south lunar pole.
The solicitation specifically seeks to support the research and development of higher-efficiency power conversion systems, such as radioisotope Stirling generators (RSGs), a specific type of RPS.
Nasa said RSGs can reduce the amount of required fuel by a factor of three to four compared to current RPS technologies while also enabling the potential use of alternative fuels.
An RSG is a type of nuclear energy technology that uses heat from fissile materials to produce electric power for operating spacecraft systems in the darkest, dustiest, and most remote places. A small amount of radioactive material, such as plutonium-238 or americium-241, naturally produces heat as it decays.
Nasa said it is looking to design, fabricate, and test an electrically heated RSG prototype for lunar applications.
It said the effort is “fundamentally a research and development initiative aimed at refining system designs and demonstrating innovative approaches where full system definitions are still evolving”.
The other technological areas included in the solicitation are for solar arrays, oxygen extraction, advanced manufacturing in space, and nanomaterials.
Nasa is looking for an RSG that is capable of providing survival heat and power for landers and rovers to endure harsh environments, such as permanently shadowed regions.
In March, Nasa announced a series of “transformative” initiatives including plans to launch a nuclear electric propulsion spacecraft to Mars in December 2028 and a three-phase plan to establish a lunar base incorporating nuclear-driven heat and power.
The focus is on operations in the south pole region of the Moon where the long nights make solar power less effective, making nuclear an important power option for a lunar base.
SR-1 Freedom Will Use Nuclear For Mars Mission
At the same time, the administration also announced a new project – Space Reactor-1 Freedom (SR-1 Freedom) – a nuclear electric propulsion rocket that Nasa plans to send to Mars in 2028.
SR-1 Freedom, will rely on an onboard fission reactor. Once SR-1 Freedom reaches Mars, it will drop three helicopters that will search the planet for underground water and potential landing sites for missions carrying humans. After completing that goal, the spacecraft might continue to investigate other worlds.
Nasa said the high efficiency and energy density of nuclear propulsion – both thermal and electric – has made its deployment a long-standing goal for space travel.
