The Space Shuttle Atlantis makes its maiden flight, carrying two DSCS-III Satellites on STS-51-J.

Space Shuttle Atlantis is a retired Space Shuttle orbiter vehicle which belongs to NASA, the spaceflight and space exploration agency of the United States. Atlantis was manufactured by the Rockwell International company in Southern California and was delivered to the Kennedy Space Center in Eastern Florida in April 1985. Atlantis is the fourth operational and the second-to-last Space Shuttle built. Its maiden flight was STS-51-J made from October 3 to 7, 1985.

The Defense Satellite Communications System (DSCS) is a United States Space Force satellite constellation that provides the United States with military communications to support globally distributed military users. Beginning in 2007, DSCS began being replaced by the Wideband Global SATCOM system. A total of 14 DSCS-III satellites were launched between the early 1980s and 2003. Two satellites were launched aboard the Space Shuttle Atlantis in 1985 during the STS-51-J flight. As of 14 September 2021, six DSCS-III satellites were still operational. DSCS operations are currently run by the 4th Space Operations Squadron out of Schriever Space Force Base.

STS-51-J was NASA's 21st Space Shuttle mission and the maiden flight of Space Shuttle Atlantis. It launched from Kennedy Space Center, Florida, on October 3, 1985, carrying a payload for the U.S. Department of Defense (DoD), and landed at Edwards Air Force Base, California, on October 7, 1985.