STS-31

The 35th Space Shuttle mission, STS-31 using Space Shuttle Discovery, launched April 24, 1990, and returned April 29.

The primary payload was the Hubble Space Telescope (HST), deployed in a 380-statute-mile orbit. The shuttle's orbit in this mission was its second highest orbit up to that date, in order that the HST could be released near to its operational altitude well outside of the atmosphere. Discovery orbited the earth 80 times in this, its 10th mission.

Secondary payloads: IMAX Cargo Bay Camera (ICBC) to document operations outside crew cabin and hand-held IMAX camera for use inside crew cabin; Ascent Particle Monitor (APM) to detect particulate matter in payload bay; Protein Crystal Growth (PCG) to provide data on growing protein crystals in microgravity; Radiation Monitoring Equipment III (RME III) to measure gamma ray levels in crew cabin; Investigations into Polymer Membrane Processing (IPMP) to determine porosity control in microgravity environment; Shuttle Student involvement program (SSIP) experiment to study effects of near-weightlessness on electrical arcs, and Air Force Maui Optical Site (AMOS) experiment.

Crew

• Commander: Loren J. Shriver
• Pilot: Charles F. Bolden, Jr
• Mission Specialist 1: Steven A. Hawley
• Mission Specialist 2: Bruce McCandless II
• Mission Specialist 3: Kathryn D. Sullivan

• NASA PAO page about STS-31