Last week, NASA took the next big step on its Journey to Mars ...
The RS-25 rocket engine, developed by Aerojet Rocketdyne, is better known as the Space Shuttle Main Engine (SSME) -- the primary rocket engines used on the space shuttle. The engines are being re-purposed and modified to support NASA's newest rocket, the Space Launch System (SLS).
On the SLS, expendable versions of the engine will be used in a cluster of four to provide thrust for the launch vehicle’s core stage. Each engine will provide a total vacuum thrust of 512,000 pounds, and increase of the 491,000 pounds vacuum thrust on the Space Shuttle.
A total of 16 RS-25 rocket engines are currently stored at NASA's Stennis Space Center, NASA's largest rocket testing facility located in Hancock, Mississippi on the banks of the Pearl River on the Mississippi-Louisiana border.
Now, the first of those engines, engine No. 2059, has been moved to the A-1 Test Stand to be flight tested in early 2016.
The RS-25 rocket engine will be tested to certify it for use on NASA's new Space Launch System (SLS) and advance the capabilities of using this vehicle in deep space and as the system of choice for getting people to Mars.
The "Block 1" version of the SLS vehicle is set to fly its first uncrewed mission in 2018.
The "Block 2" heavy-lift version will be ready for flight later and will be the largest, most powerful rocket ever built, capable of carrying humans on missions to Mars.
Testing will involve installing the flight stage on the B-2 Test Stand and firing its four RS-25 engines simultaneously, just as during an actual launch.
The 16 engines currently stored at Stennis will be made available for the first four SLS missions, and two development engines are available for ground tests.