Exploration of Jupiter 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, , has continued with eight further spacecraft missions. All of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but two have been flybys that take detailed observations without the probe 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 to reduce fuel requirements
Jupiter will be the European Space Agency's Jupiter Icy Moon Explorer (JUICE), due to launch in 2022, followed by NASA's Europa Clipper mission in 2025. There has been great interest in studying the icy moons in detail because of the possibility of subsurface liquid oceans on Jupiter's moons Europa, Ganymede, and Callisto. Funding difficulties have delayed progress. NASA's "JIMO" ("Jupiter Icy Moons Orbiter") was cancelled in 2005. A subsequent proposal was developed for a joint NASA/ESA mission called EJSM/Laplace, with a provisional launch date around 2020. EJSM/Laplace would have consisted of the NASA-led Jupiter Europa Orbiter and the ESA-led Jupiter Ganymede