All four RS-25 engines were structurally connected to the core stage for the NASA Rocket Space Launch System (SLS) for Artemis I , the first mission of SLS and the NASA spacecraft Orion.
To complete the rocket stage assembly, engineers and technicians are now integrating the propulsion and electrical systems within the structure. The completed core stage with all four connected RS-25 engines is the largest rocket stage that NASA has built since the Saturn V stages, which sent the Americans to the Moon for the first time.
The stage, which includes two huge fuel tanks, delivers more than 2 million pounds of thrust to send Artemis I to the moon. Engineers and technicians at NASA's Michoud, New Orleans, deployed the fourth RS-25 engine at the rocket stage on November 6, 2019, just one day after the third engine was physically assembled. The first two RS-25 engines were built on stage in October.
Upon completion of the assembly, crews will perform an integrated functional test of flight computers, avionics and electrical systems running throughout the 183 meter high core phase in preparation for its completion later this year. This test is the first time that all flight avionics systems have been tested together to ensure that the systems communicate with each other and properly control the flight of the rocket. Integrating the RS-25 engines into the massive core phase is a collaborative, multi-stage process for NASA and its partners, Boeing, the core phase prime contractor, and Aerojet Rocketdyne, the prime contractor for RS-25 engines.