Ganymede (moon) be launched in 2024, though this schedule might be revised and aligned with JUICE. A Ganymede orbiter based on the Juno probe was proposed in 2010 for the Planetary Science Decadal Survey. Possible instruments include Medium Resolution Camera, Flux Gate Magnetometer, Visible/NIR Imaging Spectrometer, Laser Altimeter, Low and High Energy Plasma Packages, Ion and Neutral Mass Spectrometer, UV Imaging Spectrometer, Radio and Plasma Wave sensor, Narrow Angle Camera, and a Sub-Surface Radar. Another canceled proposal to orbit Ganymede was the Jupiter Icy Moons Orbiter. It was designed to use nuclear fission for power, ion engine propulsion, and would have studied
Solar System icy objects. Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune. Most of the planets in the Solar System have secondary systems of their own, being orbited by planetary objects called natural satellites, or moons (two of which, Titan and Ganymede, are larger than the planet Mercury), and, in