List of natural satellites
Uranus has 27 named moons, five of which are massive enough to have achieved hydrostatic equilibrium. There are another 13 inner moons that orbit within Uranus's ring system, and another nine outer irregular moons. Unlike most planetary moons, which are named from antiquity, all the moons of Uranus are named after characters from the works of Shakespeare and Alexander Pope's work "The Rape of the Lock".
Oceanus (Uranus orbiter)
Since Uranus is extremely distant to the Sun (20 AU), relying in solar power is not possible past Jupiter, so the orbiter is proposed to be powered by three multi-mission radioisotope thermoelectric generators (MMRTG), a type of radioisotope thermoelectric generator. There is enough plutonium available to NASA to fuel only three more MMRTG like the one used by the "Curiosity" rover. One is already committed to the Mars 2020 rover. The other two have not been assigned to any specific mission or program, and could be available by late 2021. The trajectory to Uranus would require a Jupiter gravity assist, but such alignments are calculated to be rare in the 2020s and 2030s, so the launch windows will be scant and narrow. If launching in 2030, reaching Uranus would occur 11 years later, in 2041, and it would use two bipropellant engines for orbital insertion. Alternatively, the SLS rocket could be used for a shorter cruise time, but it would result in a faster approach velocity, making orbit insertion more challenging, especially since the density of Uranus' atmosphere is unknown to plan for safe aerobraking.