RS-25 engine installation into the Artemis II SLS Core Stage begins - NASASpaceFlight.com

Four RS-25 liquid-propellant rocket engines are being installed in NASA ’s second Space Launch System (SLS) core stage.

Installation of the upgraded former Space Shuttle Main Engines (SSME) in Core Stage-2 at MAF on Sept. 11 comes several months later than previous plans.

The engines were originally uncrated and prepped for installation early this year , around the time that the core stage engine section was mated to the rest of the stage.

Engine 2047 flew on 15 different Shuttle launches beginning with STS-91 on Orbiter Discovery in June 1998 .

Engine 2062 was assembled at KSC prior to the last Shuttle launch, but assembly of engine 2063 did not occur until it was property of the SLS program a few years later , following shipment to Stennis Space Center in Mississippi .

All four engines were trucked from Aerojet Rocketdyne’s Stennis facility to Michoud a year ago in September 2022 ; at the time the engines were expected to be installed by the end of 2022 .

The SLS core stage has reached the milestone of being ready to accept the engines and installation has begun.

Getting all four engines soft-mated first is the next major milestone.

The post-installation work that Aerojet Rocketdyne team will be supporting is a little different than with Core Stage-1 because there's no Green Run design verification campaign planned at Stennis this time around.