STS-51-B was the seventeenth flight of NASA's Space Shuttle program, and the seventh flight of Space Shuttle Challenger. The launch of Challenger on April 29, 1985 was delayed by 2 minutes and 18 seconds, due to a launch processing failure. Challenger was initially rolled out to the pad to launch on the STS-51-E mission. The shuttle was rolled back when a timing issue emerged with the TDRS-B satellite. When STS-51-E was canceled, Challenger was remanifested with the STS-51-B payloads.
Challenger landed safely at Edwards Air Force Base at 12:11 pm EDT on May 6, 1985, after a mission lasting 7 days, 8 minutes and 46 seconds.