This video shows archival footage of an RS-25 engine hot-fire test conducted by NASA at the Stennis Space Center. These powerful engines—originally used on the Space Shuttle—were upgraded and tested to power the first Space Launch System (SLS) missions, including Artemis flights to the Moon. The RS-25 engines were fired for a full 500 seconds, proving they can operate at higher power levels required for NASA’s super heavy-lift rocket. Tests like this are critical to ensuring astronaut safety and