GSE designed modifications to Building 103, a 45,000-square-foot facility in Area 47/48, to allow the transition from External Tank manufacturing to Space Launch Systems (SLS) manufacturing. Area 47/48 will be used to integrate SLS core stage sub-assemblies, including liquid hydrogen tanks, engine sections, intertanks, liquid oxygen tanks, and forward skirts. In addition to the final integration of the above-listed sub-assemblies, Building 103 will also house the installation of engines, feedline and press lines, systems tunnels with applicable wiring, and final testing and systems checkout. GSE provided structural, mechanical, electrical and fire protection design services for the renovated facility.