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Radioisotope Thermoelectric Generator (RTG)

A nuclear power source that converts the heat of decaying plutonium-238 directly into electricity. RTGs let missions operate far from the Sun or through the lunar night — powering Voyager, Cassini, and the nuclear Mars rovers Curiosity and Perseverance (the earlier rovers were solar-powered).

Highlights

  • Powers deep-space missions where sunlight is too weak

Knowledge connections

Sources

The primary and reference sources this topic draws on.

  • NASANational Aeronautics and Space Administration

    Mission data, planetary science, space telescopes, and public-domain imagery.

    Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.

  • NASA JPLJet Propulsion Laboratory / Solar System Dynamics

    Orbital data, ephemerides, and small-body parameters for planets, asteroids, and comets.