STS-41-G - Mission Summary

Mission Summary

On 5 October 1984, Challenger launched from Kennedy Space Center at 7:03 am EDT, marking the start of the STS 41-G mission. It was Challenger's sixth mission, and the 13th liftoff in the Space Shuttle program.

On board were seven crew members—the largest flight crew ever to fly on a single spacecraft at that time. They included commander Robert L. Crippen, making his fourth Shuttle flight and second in six months; pilot Jon A. McBride; three mission specialists – David C. Leestma, Sally K. Ride and Kathryn D. Sullivan – (the first time two female astronauts had flown together); and two payload specialists, Paul Scully-Power and Marc Garneau, the first Canadian citizen to serve as a Shuttle crew member, as well as the first Canadian in space.

Astronaut Sullivan became the first American woman to walk in space when she and David C. Leestma performed a 3-hour EVA on 11 October 1984, demonstrating the Orbital Refueling System (ORS) and proving the feasibility of refueling satellites in orbit.

Nine hours after liftoff, the 5,087 pounds (2,307 kg) Earth Radiation Budget Satellite (ERBS) was deployed from the payload bay by the RMS robot arm, and its on-board thrusters boosted it into orbit 350 miles (560 km) above the Earth. The ERBS was the first of three planned satellites designed to measure the amount of energy received from the Sun and reradiated into space. It also studied the seasonal movement of energy from the tropics to the polar regions.

Another major mission activity was the operation of the Shuttle Imaging Radar-B (SIR-B). The SIR-B was part of the OSTA-3 experiment package in the payload bay, which also included the Large Format Camera (LFC) to photograph Earth, another camera called MAPS which measured air pollution, and a feature identification and location experiment called FILE, which consisted of two TV cameras and two 70 mm still cameras.

The SIR-B was an improved version of a similar device flown on the OSTA-l package during STS-2. It had an eight-panel antenna array measuring 35 feet by 7 feet (11 m by 2 m). It operated throughout the flight, but problems were encountered with Challenger’s K_u band antenna, and therefore much of the data had to be recorded on board the orbiter rather than transmitted to Earth in real-time as was originally planned.

Payload Specialist Scully-Power, an employee of the U.S. Naval Research Lab, performed a series of oceanography observations during the mission. Garneau conducted a series of experiments sponsored by the Canadian government, called CANEX, which were related to medical, atmospheric, climatic, materials and robotic science. A number of GAS canisters, covering a wide variety of materials testing and physics experiments, were also flown.

A claim was later made that the Soviet Terra-3 laser testing center was used to track Challenger with a low-power laser on 10 October 1984. This supposedly caused the malfunction of on-board equipment and the temporary blinding of the crew, leading to a U.S. diplomatic protest. However, this story has been comprehensively denied by the crew members.

During the 8-day, 5-hour, 23-minute, 33-second mission, Challenger traveled 3,289,444 miles (5,293,847 km) and completed 132 orbits. It landed at the Shuttle Landing Facility at Kennedy Space Center – becoming the second shuttle mission to land there - on 13 October 1984, at 12:26 pm EDT.

The STS 41-G mission was later described in detail in the book Oceans to Orbit: The Story of Australia's First Man in Space, Paul Scully-Power by space historian Colin Burgess.