An RS-25 engine undergoes a hot-fire test.
SLS Engine Getting Ready for the Test Stand

Formerly known as the space shuttle main engine, the RS-25 accumulated over 1 million seconds—or almost 280 hours — of hot fire experience during 135 missions and numerous related engine tests like the one pictured here. Four RS-25 engines will power the core stage of NASA's Space Launch System (SLS) and the engine will go back in the stand to begin testing this summer at NASA's Stennis Space Center.

Image credit: Aerojet Rocketdyne

Page Last Updated: April 11th, 2014
Page Editor: Brooke Boen