The Exploration Mission 2 or EM-2 is scheduled to be the first crewed mission of NASA's Orion on the Space Launch System. The mission is to restart manned exploration of the Solar System. NASA plans to launch in 2023 with a crew to perform a practice flyby of a captured asteroid in lunar orbit. This mission is expected to be the first time Americans will have have left low Earth orbit since Apollo 17 in December 1972.
EM-2 is a single-launch mission of a Space Launch System Block IB with an Exploration Upper Stage, lunar Block 1 Orion Multi-Purpose Crew Vehicle (MPCV) and a payload insertion of 50.7 t. It would be a ten- to fourteen-day mission with a crew of four astronauts who would spend four days in lunar orbit. Its current description is "Crewed mission to enter lunar orbit, test critical mission events, and perform operations in relevant environments". The target for EM-2, as of 2015, might be to perform a flyby of a captured asteroid in lunar orbit, to be conducted in 2023.