Juno was the first NASA mission to use solar power while operating in orbit around Jupiter, beginning its orbital mission in 2016.
Launched on August 5, 2011, Juno reached Jupiter on July 4, 2016. Its three large solar arrays provide electricity far from the Sun, where sunlight is much weaker than near Earth. Earlier spacecraft that visited Jupiter generally used radioisotope thermoelectric generators instead.
Juno’s polar orbit lets it pass over Jupiter’s poles and avoids spending most of its time inside the planet’s intense radiation belts. Its instruments investigate Jupiter’s atmosphere, magnetic field, gravity, auroras, and deep interior.
Galileo was the first spacecraft to orbit Jupiter, but it used radioisotope power. Juno therefore holds a different record: the first solar-powered spacecraft to orbit the giant planet.