The Uranus orbiter and probe, also known as Uranus Pathfinder by the European Space Agency, is a concept study by NASA and ESA on a mission to the planet Uranus. The mission would be a follow-up to Voyager 2's flyby in 1986. Two possibilities for transfer to Uranus have been considered: one, using an Atlas V 551 to launch the spacecraft into a trajectory that will make use of multiple gravity assists from Earth, Venus, and Jupiter, and the other using the Space Launch System to launch the spacecraft directly towards Uranus.