Media and social media followers are invited to watch as NASA tests an RS-25 engine like those that will power the rocket that launches astronauts on missions to an asteroid and to Mars. The test will take place Thursday, August 13, at NASA’s Stennis Space Center in Mississippi.

Four RS-25 engines will power the core stage of NASA’s new Space Launch System (SLS), the rocket that will launch the agency’s Orion crew capsule on deep space missions. The RS-25 engine is a modified space shuttle main engine, which powered missions into low-Earth orbit for 30 years. Remaining space shuttle main engines are being upgraded to provide the additional thrust needed for the SLS vehicle.

The test will verify that the RS-25 developmental engine is performing as needed. Engineers especially are focused on verifying the performance of the new RS-25 engine controller component, or “brain.” The controller monitors and regulates engine performance during an engine firing. Testing of RS-25 engines that will be used for flight is expected to begin this fall at Stennis.

Media wishing to attend the test must contact Valerie Buckingham at 228-688-3898 or to request credentials.

Forty social media participants will be selected to view the test firing, tour Stennis facilities and interview NASA and Aerojet Rocketdyne officials as part of a NASA Social event at the test. Interested participants can apply for social media accreditation at: 

All social media accreditation applications will be considered on a case-by-case basis. The application process closes at 5 p.m. EDT Monday, July 6. Because portions of this event may take place in restricted areas, registration is limited to U.S. citizens.

Stennis will test all of the RS-25 engines used on early SLS missions, including those that will launch the vehicle’s first uncrewed mission, Exploration Mission-1. Stennis also is preparing to test the SLS core stage, which will involve firing four RS-25 engines simultaneously. 

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the SLS Program for the agency.

For more information about SLS, visit:

For information about Stennis Space Center, visit: