Exploration of Jupiter
The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of Pioneer 10 into the Jovian system in 1973, and, as of 2023, has continued with eight further spacecraft missions in the vicinity of Jupiter. All of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but two were flybys taking detailed observations without landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys. On 5 July 2016, spacecraft Juno arrived and entered the planet's orbit—the second craft ever to do so. Sending a craft to Jupiter is difficult, mostly due to large fuel requirements and the effects of the planet's harsh radiation environment.
The first spacecraft to visit Jupiter was Pioneer 10 in 1973, followed a year later by Pioneer 11. Aside from taking the first close-up pictures of the planet, the probes discovered its magnetosphere and its largely fluid interior. The Voyager 1 and Voyager 2 probes visited the planet in 1979, and studied its moons and the ring system, discovering the volcanic activity of Io and the presence of water ice on the surface of Europa. Ulysses further studied Jupiter's magnetosphere in 1992 and then again in 2004. The Cassini probe approached the planet in 2000 and took very detailed images of its atmosphere. The New Horizons spacecraft passed by Jupiter in 2007 and made improved measurements of its and its satellites' parameters.
The Galileo spacecraft was the first to have entered orbit around Jupiter, arriving in 1995 and studying the planet until 2003. During this period Galileo gathered a large amount of information about the Jovian system, making close approaches to all of the four large Galilean moons and finding evidence for thin atmospheres on three of them, as well as the possibility of liquid water beneath their surfaces. It also discovered a magnetic field around Ganymede. As it approached Jupiter, it also witnessed the impact of Comet Shoemaker–Levy 9. In December 1995, it sent an atmospheric probe into the Jovian atmosphere, so far the only craft to do so.
In July 2016, the Juno spacecraft, launched in 2011, completed its orbital insertion maneuver successfully, and is now in orbit around Jupiter with its science programme ongoing.
The European Space Agency selected the L1-class JUICE mission in 2012 as part of its Cosmic Vision programme to explore three of Jupiter's Galilean moons, with a possible Ganymede lander provided by Roscosmos. JUICE was launched on April 14, 2023. The Russian lander did not materialize in the end.
NASA plans to launch a spacecraft, Europa Clipper, to study the moon Europa in 2024.
The Chinese National Space Administration plans to launch two Interstellar Express missions in 2024 on a flyby of Jupiter and Tianwen-4 around 2029 to explore the planet and Callisto.
A list of previous and upcoming missions to the outer Solar System (including Jupiter) can be found at the List of missions to the outer planets article.