NASA engineers picked up this year where they left off in 2017, conducting a certification test of another RS-25 engine flight controller on Jan. 16, 2018, on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Mississippi. The 365-second, full-duration test came a month after the space agency capped a year of RS-25 testing with a flight controller test in mid-December. A 3D printed part tested in December was tested again. This rocket engine component, a pogo accumulator assembly, is part of an ongoing series of tests with parts made using advanced manufacturing techniques that will make building future engines more affordable.
For this “green run” test, the flight controller was installed on RS-25 developmental engine E0528 and fired just as during an actual launch. Once certified, the flight controller will be removed and installed on a flight engine for use by NASA’s new deep-space rocket, the Space Launch System (SLS). NASA is building SLS as the most powerful rocket in the world, designed to carry humans on the Orion spacecraft and enable missions to the Moon and Mars.
Launch of the SLS rocket will be fueled by four RS-25 engines firing simultaneously to generate 2 million pounds of thrust and working in conjunction with a pair of solid rocket boosters to produce more than 8 million pounds of thrust.
RS-25 engines for the initial SLS flights are former space shuttle main engines, modified to provide the additional power needed by the larger SLS rocket. A key part of that modification is the new flight controller, which works as the RS-25 “brain,” helping the engine communicate with the SLS rocket and providing precision control of engine operation and internal health diagnostics. NASA is testing all RS-25 engines and flight controllers for SLS missions at Stennis.
The initial SLS Exploration Mission-1 (EM-1) will serve as the first test flight for the new rocket and will carry an uncrewed Orion spacecraft. All the engines for this flight have been tested at Stennis and are ready to be attached to the rocket’s core stage being built at NASA’s Michoud Assembly Center in New Orleans. Current engine tests are for controllers for Exploration Mission-2, the first flight that will transport astronauts aboard Orion.
In addition to testing the engines for those flights at Stennis, NASA is preparing the B-2 Test Stand at the center to test the entire SLS core stage with its four engines for EM-1. This “green run” testing will involve installing the flight core stage on the B-2 stand and firing all four RS-25 engines simultaneously, just as during an actual launch. RS-25 tests at Stennis are conducted by a team of NASA, Aerojet Rocketdyne and Syncom Space Services engineers and operators. Aerojet Rocketdyne is the RS-25 prime contractor. Syncom Space Services is the prime contractor for Stennis facilities and operations.