Final RS-25 Engine Delivered to KSC — All Four Artemis III Core Stage Engines Now on Site

The fourth and final RS-25 engine for the Artemis III SLS core stage arrived at Kennedy Space Center's Vehicle Assembly Building on Tuesday, July 21, 2026, shipped from NASA's Stennis Space Center near Bay St. Louis, Mississippi. All four RS-25 engines — built by L3Harris Technologies and derived from Space Shuttle-era hardware — are now on site; technicians will integrate them with the core stage over the summer. NASA Administrator Jared Isaacman marked the milestone while continuing to publicly push the compressed 'Artemis Acceleration' timeline.