STS-51J

STS-51J was NASA's 21st Space Shuttle mission and the first flight of Space Shuttle Atlantis. The crew launched from Kennedy Space Center's Launch Complex 39A on October 3, 1985, with Karol J. Bobko as commander, Ronald J. Grabe as pilot, Robert L. Stewart and David C. Hilmers as mission specialists, and William A. Pailes as payload specialist. It was the second Shuttle mission dedicated to a Department of Defense payload, so public details during the flight were deliberately limited. NASA's later history material notes that the primary payloads were declassified in 1998 as two third-generation Defense Satellite Communications System spacecraft, DSCS III USA-11 and USA-12, deployed from Atlantis on an Inertial Upper Stage. NASA's mission page lists the flight at 4 days, 1 hour, 44 minutes, and 38 seconds, with 64 orbits and landing on Runway 23 at Edwards Air Force Base on October 7, 1985. The flight completed the original four-orbiter Shuttle fleet and gave Atlantis its operational debut.