Space Launch System (SLS)

The Space Launch System (SLS) is an American super heavy-lift expendable launch vehicle developed by NASA starting in 2011.

The first launch, designated Artemis 1, occurred on November 16, 2022, from Kennedy Space Center. It replaces the Ares I and Ares V launch vehicles, which were cancelled along with the rest of the Constellation program, a previous program aimed to return to the Moon.

The SLS is the successor to the retired Space Shuttle, and the primary launch vehicle of NASA’s deep space exploration plans through the 2020s. The SLS has the highest payload capacity of any currently operational launch vehicle and the third-highest capacity of any rocket ever to reach orbit, trailing the Energia and Saturn V.

Crewed lunar flights are planned as part of the Artemis program, leading to a possible human mission to Mars. The SLS is being developed in three major phases with increasing capabilities: Block 1, Block 1B, and Block 2. SLS Block 1 launch vehicles are to launch the first three Artemis missions and five subsequent SLS flights are planned to use Block 1B, after which all flights will use Block 2.

The SLS was explicitly designed to launch the deep space Orion spacecraft and make use of the ground operations and launch facilities at NASA’s Kennedy Space Center in Florida. Artemis is projected to use at most one SLS each year until at least 2030. SLS is launched exclusively from LC-39B at the Kennedy Space Center.

The first launch was originally mandated by Congress for December 2016, but was delayed by six years from the original six-year program schedule.

After the first four Artemis missions, NASA plans to transfer production and launching of the Space Launch System to Deep Space Transport LLC, a joint venture between Boeing and Northrop Grumman.