Radioisotope Power Systems

Space nuclear power to explore the deepest, dustiest, darkest, and most distant regions of our solar system and beyond.

NOW

Active Missions

Years in Service at NASA

Active Missions

Artists's concept of a Voyager spacecraft in deep space.

RPS — short for radioisotope power systems — are a type of nuclear energy technology that uses heat to produce electric power for operating spacecraft systems and science instruments. That heat is produced by the natural radioactive decay of plutonium-238.

FEATURED STORY

NASA to Explore Two Landing Options for Returning Samples from Mars

Both potential options would use a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) that can provide power and heat through the dust storm season at Mars, allowing for reduced complexity.

To maximize chances of successfully bringing the first Martian rock and sediment samples to Earth for the benefit of humanity, NASA announced Tuesday a new approach to its Mars Sample Return Program. The agency will simultaneously pursue two landing architectures, or strategic plans, during formulation, encouraging competition and innovation, as well as cost and schedule savings.

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The rover is upside down in this straight from the back view. The image is centered on a cylinder with fins, the spacecraft's Radioisotope Thermoelectric Generator.

The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) for NASA'S Mars 2020 Perseverance rover is shown during a fit check with the rover in a payload processing facility at NASA's Kennedy Space Center in Florida on April 16-17, 2020.

NASA/JPL-Caltech/KSC/DOE

Voyager Mission

New Science from Voyager 2
NASA’s Voyager 2 flyby of Uranus decades ago shaped scientists’ understanding of the planet but also introduced unexplained oddities. A recent data dive has offered answers.

The Voyagers owe their ability to operate at such great distances from the Sun to their nuclear electric power sources, which provide the electrical power they need to function.

Dr. Edward Stone (1936-2024)

Voyager Project Scientist

Why Radioisotope Power Systems?

RPS provide electricity and heat that enable spacecraft to explore beyond the capabilities of solar power, chemical batteries, and fuel cells.

u.s. flag visible on spacecraft in clean room

POWER TO EXPLORE

RPS offer the key advantage of operating continuously over long-duration space missions, largely independent of changes in sunlight, temperature, charged particle radiation, or surface conditions like thick clouds or dust.

En esta imagen, el rover Perseverance de la NASA muestra la roca 'Chevaya Falls' cerca del centro, tomada en un autorretrato compuesto por 62 im�genes.

A CRITICAL TECHNOLOGY

RPS — short for radioisotope power systems — are sometimes referred to as a type of "nuclear battery." Some of the excess heat produced by RPS can be used to enable spacecraft systems to operate in extremely cold environments.

An astronaut in a spacesuit removes a cylinder from the side of a lunar lander on the Moon.

A LEGACY OF EXPLORATION

RPS have enabled NASA's exploration of the solar system since the Apollo era of the late 1960s. The U.S. Navy launched the first radioisotope power system in 1961. A total of 24 NASA missions have successfully flown with an RPS since 1969. Five radioisotope power systems powered missions are currently active.

Powered by RPS: Great Shots from Around the Solar System

26 Images

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Earth is a tiny pixel of white in a dusty sunbeam in this image of the vast emptiness of deep space.

Magestic Saturn and its rings are barely illuminated view of the entire planet.

Giant Jupiter is half illuminated by the Sun and its moon Io is a crescent in the foreground. A small glowing volcanic plume is erupting from Io.

A sweeping landscape gives way to hills on the colorized horizon in this artistic Mars composite image.

The image from NASA's Voyager 2 shows the Great Dark Spot and its companion bright smudge; on the west limb the fast moving bright feature called Scooter and the little dark spot are visible.

This false-color photograph is a composite of 15 images of the Moon taken through three color filters NASA Galileo solid-state imaging system during the spacecraft passage through the Earth-Moon system on December 8, 1992.

A color-enhanced image shows cloud patterns moving around a hexagon -shaped storm om Satirm.

In the early morning hours of July 8, 2015, mission scientists received this new view of Pluto -- the most detailed yet returned by New Horizons. The image was taken on July 7, when the NASA spacecraft was just under 5 million miles 8 million kilometers

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Radioisotope Power Across the Solar System

Space nuclear power to explore the deepest, dustiest, darkest, and most distant regions of our solar system and beyond.

NASA

Latest News

More RPS News

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NASA to Explore Two Landing Options for Returning Samples from Mars

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NASA Mars Orbiter Spots Retired InSight Lander to Study Dust Movement

Engineers in cleanroom suits insert a cylindrical device into a spacecraft.

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After 60 Years, Nuclear Power for Spaceflight is Still Tried and True

Article3 months ago

Thre children, a boy and two girls, sit on a model rock formation.

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Perseverance Pays Off for Student Challenge Winners

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Here’s How Curiosity’s Sky Crane Changed the Way NASA Explores Mars

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Learn More and Get Involved

Power to Explore Student Essay Challenge 2025
K-12 students, your task is to plan a mission that uses Radioisotope Power Systems (RPS) to a dark, dusty, or far away moon in our solar system.
U.S. Department of Energy
The NASA Radioisotope Power Systems Program is a joint partnership with the U.S. Department of Energy.