Natural satellite achieved hydrostatic equilibrium, and Uranus has five. It has been suggested that some satellites may potentially harbour life. Among the identified dwarf planets, Ceres has no known natural satellites. Pluto has the relatively large natural satellite Charon and four smaller natural satellites; Styx, Nix, Kerberos, and Hydra. Haumea has two natural satellites, and Eris and Makemake have one each. The Pluto–Charon system is unusual in that the center of mass lies in open space between the two, a characteristic sometimes associated with a double-planet system. The seven largest natural satellites in the Solar System (those bigger than 2,500 km across)
Exploration of Pluto launched in 2030, marking the 100th anniversary of Pluto's discovery, and spending 7-8 years traveling to the Pluto system. The Fusion-Enabled Pluto Orbiter and Lander was a 2017 phase I report funded by the NASA Innovative Advanced Concepts (NIAC) program. The report, written by principal investigator Stephanie Thomas of Princeton Satellite Systems, Inc., describes a Direct Fusion Drive (DFD) mission to Pluto. A fusion reactor would be used to send a 1000 kg orbiter and lander to the Pluto system in only four years (more than twice as fast as "New Horizons"). Global Aerospace Corporation presented a Pluto lander concept