STS-61-E

STS-61-E was a NASA Space Shuttle mission planned to launch on 6 March 1986 using Columbia. It was canceled after the Challenger disaster.

Mission objectives
Columbia was to carry the ASTRO-1 observatory, which would be used to make astronomical observations including observations of Halley's Comet. ASTRO-1 consisted of three ultraviolet telescopes mounted on two Spacelab pallets, controlled by the Instrument Pointing System (IPS) which was first tested on STS-51-F.

After the Challenger disaster, the flight was remanifested as STS-35 and several crew members were replaced. Both Richards and Leestma were reassigned to STS-28 while McBride left NASA in 1989. Vance D. Brand replaced McBride as the commander while Guy S. Gardner and John M. Lounge replaced Richards and Leestma, respectively.