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Radioisotope Power Systems

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About the Radioisotope Power Systems Program

The Radioisotope Power Systems (RPS) Program is a technology development effort, managed by NASA, that is strategically investing in nuclear power technologies that would maintain NASA's current space science capabilities and could enable future space exploration missions. NASA, working in collaboration with the U.S. Department of Energy (DOE) funds research and development efforts on Stirling technology for a potential Stirling Radioisotope Generator (SRG), and new thermoelectric materials, such as skutterudite-based thermoelectric couples that could be integrated into the Mult-Mission Radioisotope Thermoelectric Generator (MMRTG) to create an enhanced MMRTG (eMMRTG). NASA also works with DOE to maintain the capability to produce MMRTGs; the first MMRTG to be launched, now provides electrical power and heat for the Mars Science Laboratory rover, Curiosity.The MMRTG has been baselined for use as the power source for the Mars 2020 mission as well.

The RPS program is designed to enable more capable future space missions by supporting the development of advanced technologies for power conversion using heat from the natural decay of plutonium-238. DOE owns and produces the nuclear fuel and the nuclear power systems, and directly manages the design and development of all radioisotope power systems used by NASA.

Program Organization

The NASA RPS Program is a multi-center effort among the NASA Glenn Research Center, the NASA Jet Propulsion Laboratory(JPL), and the Johns Hopkins University Applied Physics Laboratory (APL). The program reports to the leadership of NASA's Science Mission Directorate (Planetary Science Division) at NASA Headquarters. The Program is managed by GRC on behalf of NASA Headquarters.

GRC has decades of experience developing the Stirling converter technology that could be utilized by a potential future SRG. As part of its program management responsibilities, GRC leads program planning, financial tracking, and scheduling activities. JPL provides support for program planning and mission analysis, as well as continued research and development of improved thermoelectric materials that could be employed by future radioisotope thermoelectric generators, or RTGs. JPL also supports launch approval engineering, which is concerned with engineering, communications, and regulatory issues related to the safe launch of radioisotope power systems. APL supports the RPS program with mission and systems analyses.

For Further Information

To learn more about the RPS Program, visit the program web pages, or contact the program by email.

NASA missions enabled by radioisotope power:

*A full list of missions is available at

*Sort missions by clicking the column headers.

*Sort missions by clicking the column headers.

DivisionNameLaunch DatePhase
Planets Cassini
The Cassini Mission is in the midst of a detailed study of Saturn, its rings, its magnetosphere, its icy satellites, and its moon Titan. Cassini also delivered a probe (called Huygens, provided by the European Space Agency) to Titan, and ...
19971015 October 15, 1997 3Operating
Planets Galileo
The Galileo mission produced a string of discoveries about asteroids, a fragmented comet, Jupiter's atmosphere, Jupiter's magnetic environment, and especially about the geologic diversity of Jupiter's four largest moons. This mission is part of SMD's Outer Planets Flagship program.
19891018 October 18, 1989 4Past
Planets Mars Exploration Rover - Opportunity
The Mars Exploration Rover Opportunity was originally designed for a 90 Sol mission (a Sol, one Martian day, is slightly longer than an Earth day at 24 hours and 37 minutes). Its mission has been extended several times as it ...
20030707 July 07, 2003 3Operating
Planets Mars Exploration Rover - Spirit
Mars Exploration Rover Spirit landed in Gusev crater on Mars in January 2004. The rover carries a sophisticated set of instruments that allow it to search for evidence of liquid water that may have been present in the planet's past. ...
20030610 June 10, 2003 4Past
Planets Mars Pathfinder
Mars Pathfinder launched December 2, 1996 and arrived on the surface of Mars on July 4, 1997. The mission was an engineering demonstration of key technologies and concepts for use in future missions to Mars; it also delivered science instruments ...
19961204 December 04, 1996 4Past
Planets Mars Science Laboratory
NASA proposes to develop and to launch a roving long-range, long-duration science laboratory that will be a major leap in surface measurements and pave the way for a future sample return mission. The mission will also demonstrate the technology for ...
20111126 November 26, 2011 3Operating
Planets New Horizons
The New Horizons Pluto-Kuiper Belt Mission will help us understand worlds at the edge of our solar system, by making the first reconnaissance of Pluto and Charon. The mission will then visit one or more Kuiper Belt Objects, in the ...
20060119 January 19, 2006 3Operating
Planets Pioneer 10 & 11
These Pioneer missions traveled through the asteroid belt to observe Jupiter, Saturn and continue on to the outer solar system.
19720303 March 03, 1972 4Past
Heliophysics Ulysses
The Ulysses Mission was the first spacecraft to explore interplanetary space at high solar latitudes, orbiting the Sun nearly perpendicular to the plane in which the planets orbit. This mission was part of SMD's Heliophysics Research program.
19901006 October 06, 1990 4Past
Planets Viking 1 - 2
Two Viking spacecraft, each composed of an orbiter and a lander, flew to Mars in the mid 1970's. They measured atmospheric water vapor, did chemical analysis of the soil, and took photographs of the entire surface.
19750820 August 20, 1975 4Past
Heliophysics Voyager
The twin Voyager 1 and 2 spacecraft continue exploring where nothing from Earth has flown before. In the 25th year after their 1977 launches, they each are much farther away from Earth and the Sun than Pluto is and approaching ...
19770905 September 05, 1977 3Operating