Spaceflight Insider

NASA conducts 5th test of RS-25 engine flight controller unit

RS-25 engine test on August 30, 2017

NASA capped off summer with a 500-second hot-fire test of a fifth RS-25 engine flight controller unit on the A-1 Test Stand at its Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 30, 2017. Photo Credit: NASA

The final test of the RS-25 engine for the new Space Launch System (SLS) took place on August 30, 2017, at Stennis Space Center near Bay St. Louis, Mississippi. The 500-second hot-fire test is the fifth of the RS-25 engine flight controller unit on the A-1 test stand.

Four RS-25 engines will be integrated with the SLS rocket with the Orion spacecraft during the first test flight, Exploration Mission-1 (EM-1). A controller communicates with the SLS flight computers to ensure that the engines are performing at accurate levels. The new flight controllers are a critical component of engine modification.

During tests, the controllers are installed on a developmental RS-25 engine, which is then fired in the same method. The test is another step closer toward the United States’ mission to return to human deep-space exploration missions. NASA launched a series of summer tests beginning at the end of May, followed by three additional tests.

The four engines generate a combined 2 million pounds-force (8,900 kilonewtons) of thrust at liftoff. With the boosters, total thrust at liftoff will exceed 8 million pounds-force (35,590 kilonewtons). The RS-25 engines designated for use on the initial SLS missions are former Space Shuttle Main Engines, modified to provide the additional power for the larger, heavier SLS rocket.

On the SLS, expendable versions of the engine will provide thrust for the vehicle’s core stage. While engines on the Space Shuttle ran at 491,000 pounds-force (2,184 kilonewtons) of vacuum thrust, the power level was increased for the SLS to 512,300 pounds-force (2,279 kilonewtons) of vacuum thrust to augment the vehicle’s heavy-lift capability.

A total of 16 RS-25 engines are stored at Stennis. The tests, which began in 2015, are conducted by a team of NASA, Aerojet Rocketdyne, and Syncom Space Services engineers and operators.

Video courtesy of NASA



Heather Smith's fascination for space exploration – started at the tender age of twelve while she was on a sixth-grade field trip in Kenner, Louisiana, walking through a mock-up of the International Space Station and seeing the “space potty” (her terminology has progressed considerably since that time) – she realized at this point that her future lay in the stars. Smith has come to realize that very few people have noticed how much spaceflight technology has improved their lives. She has since dedicated herself to correcting this problem. Inspired by such classic literature as Anne Frank’s Diary, she has honed her writing skills and has signed on as The Spaceflight Group’s coordinator for the organization’s social media efforts.

Reader Comments

⚠ Commenting Rules

Post Comment

Your email address will not be published. Required fields are marked *