On October 21, NASA specialists conducted a test of the RS-25 rocket engine with serial number 10001 at the Fred Haise Test Stand at the John C. Stennis Space Center, located near Bay Saint Louis, Mississippi. The test team ran the experimental engine for almost eight and a half minutes, which amounts to approximately 500 seconds of continuous operation. This is exactly how long the RS-25 engines operate during an actual launch of the SLS (Space Launch System) heavy-lift launch vehicle, which is used in the Artemis program for lunar missions. Such tests allow NASA engineers to gather data on engine performance under conditions that closely simulate an actual launch and to verify its reliability and characteristics before use in future missions. The Artemis program aims to return humans to the Moon and subsequently prepare for crewed missions to Mars, with the SLS rocket serving as a key element of this program by providing the necessary thrust to place spacecraft on a trajectory toward the Moon. RS-25 engine tests are conducted regularly to confirm their readiness for operation and to refine the design before subsequent launches.