Engineers at NASA’s Michoud Assembly Facility in New Orleans have completed the “forward join,” connecting structures to form the top part of NASA’s Space Launch System (SLS) rocket’s core stage. This first core stage will send Exploration Mission-1, the first integrated flight of SLS and the Orion spacecraft, out beyond the Moon. The forward join mated three structures shown above: the forward skirt, the liquid oxygen tank and the intertank. This milestone marks the beginning of integration and assembly of the massive, 212-foot-tall SLS core stage, which will include the rocket’s four RS-25 rocket engines, propellant tanks, and flight computers. Now, NASA and Boeing, the SLS prime contractor, will continue to integrate various systems inside the forward part of the core stage and prepare for structural joining of the liquid hydrogen tank and engine section to form the bottom of the stage. These two parts of the core stage will then be assembled to form the largest stage NASA has ever built. Watch this video showing how the structures were connected.