One Of Four That Will Power Core Stage Of SLS

NASA will conduct the "penultimate" hot fire test of an RS-25 engine on Thursday. This is one of four engines that will power the core stage of NASA’s new Space Launch System (SLS), and carry the agency’s Orion crew capsule as part of the journey to Mars and other deep space destinations.

The test will begin at 1700 EDT and will last 535 seconds, the amount of time the engines will fire during an actual launch.

The test will take place on the historic A-1 test stand at NASA’s Stennis Space Center in Mississippi and is part of a series designed to put the upgraded former space shuttle main engines through the rigorous temperature and pressure conditions they will experience during a launch.

The tests also support the development of a new controller, or “brain,” for the engine, which monitors engine status and communicates between the vehicle and the engine, relaying commands to the engine and transmitting data back to the vehicle. The controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine's health and status.

FMI: www.nasa.gov/exploration/systems/sls/rocket.html