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Test Qualifies Final Main Engine Controller for First Crewed SLS Launch

Written by: Space Foundation Editorial Team

STENNIS SPACE CENTER, Miss. (Feb. 1, 2018) – NASA and Aerojet Rocketdyne today cleared a significant milestone toward the first crewed flight of the agency’s Space Launch System (SLS) with the latest successful test firing of an RS-25 engine, which powers the heavy-lift rocket’s first stage.

The 365-second test qualified the fourth and final RS-25 engine controller for Exploration Mission-2 (EM-2), which will see the SLS launch astronauts aboard NASA’s Orion spacecraft in the 2020s. The new controller serves as the brain of the engine, enabling it to communicate with the SLS, manage thrust levels, and monitor its performance. The first stage of each SLS vehicle is powered by four RS-25s, derived from the Aerojet Rocketdyne-built Space Shuttle Main Engine.

“We are thrilled to mark another important step toward humankind’s first foray beyond low Earth orbit since 1972,” said Eileen Drake, Aerojet Rocketdyne CEO and president.
Also featured on today’s test was an additively manufactured component known as the Pogo Accumulator Assembly, designed to dampen vibrations that can cause the launch vehicle to become unstable in flight. About the size of a beach ball, the Pogo system is the largest additively manufactured component tested on the RS-25 to date.

“This is the third of four scheduled tests to confirm not only the functional performance of the Pogo, but also to verify the structural margins and capabilities,” said Dan Adamski, Aerojet Rocketdyne director for the RS-25 program. “All the data gathered to date has matched up very well with our predictions.”

Newly built RS-25 engines, the first six of which are under contract to NASA for future SLS flights, will contain numerous additively manufactured components, including the Pogo Accumulator Assembly, to help keep costs down. Testing of the Pogo hardware will continue through the month of February.

Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), is an innovative company delivering solutions that create value for its customers in the aerospace and defense markets. The company is a world-recognized aerospace and defense leader that provides propulsion and energetics to the space, missile defense and strategic systems, tactical systems and armaments areas, in support of domestic and international markets. Additional information about Aerojet Rocketdyne can be obtained by visiting our websites at and

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Mary Engola, Aerojet Rocketdyne
[email protected]

Steve Warren, Aerojet Rocketdyne
[email protected]