RS-25 Engine Completes 500-Second Test.

An RS-25 engine fired up for 500 seconds June 11 at NASA's Stennis Space Center near Bay St. Louis, Mississippi. Four RS-25 engines will power NASA's new rocket, the Space Launch System, to send astronauts on future missions beyond Earth’s orbit, including to an asteroid and ultimately to Mars. This is the third firing of an RS-25 development engine on the A-1 test stand at Stennis, with four more tests planned for the current development engine.