Illustration of Cassini speeding through the gap between Saturn and planet's the innermost rings.
Europa Clipper over Europa
Artist's rendition of NASA's Galileo at Jupiter.

Outer Planets and
Ocean Worlds Program

The successful Galileo and Cassini missions to Jupiter and Saturn greatly deepened our understanding of those giant planets and their intriguing moons. But they have also raised more questions. The Europa Clipper mission is currently in development and scheduled for launch in 2024, and various other missions (such as a Europa Lander) are in very early stages of study.

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Missions Supporting this Program

Europa Clipper over Europa

Europa Clipper

NASA's Europa Clipper will conduct detailed reconnaissance of Jupiter's moon Europa and investigate whether the icy moon could have conditions suitable for life. (Launching 2024)

Cassini at Saturn


A joint endeavor of NASA, ESA, and ASI, Cassini was a sophisticated robotic spacecraft sent to study Saturn and its complex system of rings and moons in unprecedented detail. (1997-2017)

Artist's rendition of NASA's Galileo at Jupiter.


The findings from Galileo, the first spacecraft to orbit Jupiter and make close passes by all its major moons, significantly changed the way we view the solar system. (1989-2003)

Illustration of spacecraft at Jupiter with four moons visible.


NASA is cooperating with ESA on the Jupiter Icy Moons Explorer (JUICE) mission to study Jupiter and its moons Ganymede, Callisto, and Europa. (2023-present)

Artist's rendition of NASA's Voyager spacecraft

Voyager 1

Voyager 1 visited Jupiter and Saturn like its twin spacecraft, Voyager 2, and then it kept going, becoming the first human-made object to enter interstellar space in 2012. (1977-present)

Voyager's Magnetometer Boom

Voyager 2

Voyager 2 flew by Jupiter and Saturn then continued alone to Uranus and Neptune, still the only spacecraft to visit those two distant giants, later reaching interstellar space in 2018. (1977-present)

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