NASA won't be sending astronauts aboard the first integrated flight of the SLS rocket and the Orion capsule. it was initially considered but was scrapped later on.
NASA"s most powerful rocket won't be flying its maiden flight on 2018. This is after GAO reported that there is very little time to prepare for the first flight given the difficulties the mission is facing.
NASA will look into the possibility of sending astronauts aboard the first flight of the SLS rocket. Exploration Mission 1 will be the maiden flight of Orion and SLS together.
NASA is concluding a series of successful tests in preparation for the first integrated flight in 2018, which include the Orbital ATK rocket test, the RS-25 engine test, the welding on the liquid hydrogen tank, and most recently, the Orion parachute test.