STS-51B Fact Sheet

By Cliff Lethbridge

STS-51B — Challenger

17th Space Shuttle Mission

7th Flight of Challenger


Robert F. Overmyer, Commander

Frederick D. Gregory, Pilot

Don L. Lind, Mission Specialist

Norman E. Thagard, Mission Specialist

William E. Thornton, Mission Specialist

Lodewijk van den Berg, Payload Specialist

Taylor G. Wang, Payload Specialist

Orbiter Preparations:

Tow to Orbiter Processing Facility – October 13, 1984

Rollover to Vehicle Assembly Building – February 10, 1985

Rollout to Launch Pad 39A – February 15, 1985

Rollback to Vehicle Assembly Building – March 4, 1985

Rollover to Orbiter Processing Facility – March 7, 1985

Rollover to Vehicle Assembly Building – April 10, 1985

Rollout to Launch Pad 39A – April 15, 1985


April 29, 1985 – 12:02:18 p.m. EDT. The mission was first manifested as STS-51E, but was rolled back from the launch pad due to a timing problem in the Tracking and Data Relay Satellite-2 (TDRS-2) main payload. Subsequently, mission STS-51E was canceled.

Challenger was remanifested with STS-51B payloads. TDRS-2 was reassigned to mission STS-51L. April 29 launch was delayed 2 minutes, 18 seconds due to a launch processing system failure.


May 6, 1985 – 9:11:04 a.m. PDT at Runway 17, Edwards Air Force Base, California. Rollout distance was 8,317 feet. Rollout time was 59 seconds. Mission duration was 7 days, 0 hours, 8 minutes, 46 seconds. Landing occurred during the 111th orbit.

Mission Summary:

The mission’s primary payload was Spacelab-3. This was the first operational flight for the Spacelab orbital laboratory series developed by the European Space Agency (ESA). Studies were held in materials sciences, life sciences, fluid mechanics, atmospheric physics and astronomy.

The lion’s share of experimentation was on materials processing in a microgravity environment. However, two monkeys and 24 rodents were observed for effects of weightlessness. Of 15 primary Spacelab experiments, 14 were considered successful. Two GAS experiments were also conducted.