The Space Shuttle Main Engine (SSME) reached a historic milestone July 16, 2004, when a successful flight acceptance test was conducted at NASA Stennis Space Center (SSC). The engine tested today is the first complete engine to be tested and shipped in its entirety to Kennedy Space Center for installation on Space Shuttle Discovery for STS-114, NASA's Return to Flight mission. The engine test, which began about 3:59 p.m. CDT, ran for 520 seconds (8 minutes), the length of time it takes for the Space Shuttle to reach orbit.