RS-25D engine

Employees unload a RS25D rocket engine at NASA's John C. Stennis Space Center on Jan. 17. The engine - and 14 others - will be stored at the facility for future testing and use on NASA's new Space Launch System (SLS). The SLS is a new heavy-lift launch vehicle that will expand human presence beyond low-Earth orbit and enable new missions of exploration across the solar system. NASA's Marshall Space Flight Center in Huntsville, Ala., is leading the design and development of the Space Launch System for NASA, including the engine testing program. Delivery of the 15 RS-25 engines will continue throughout the next few months