"6_2_2_3_14.TXT" (2933 bytes) was created on 01-02-89 STS 41-G On Oct. 5, 1984, Challenger returned to flight with its launch at 7:03 a.m. 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; 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. Astronaut Sullivan became the first woman to walk in space when she and David C. Leestma performed a 3 hour EVA on Oct. ll demonstrating the Orbital Refueling System (ORS) and proving the feasibility of refueling satellites in orbit. Nine hours after liftoff, the 5,087-lb, Earth Radiation Budget Satellite (ERBS) was deployed from the payload bay by the RMS arm, and its on-board thrusters boosted it into an orbit 350 miles above the Earth. 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, operation of the Shuttle Imaging Radar-B (SIR-B) was conducted. 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 70mm still cameras. The SIR-B effort 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 by 7 feet. It operated throughout the flight but problems were encountered with the Challenger's Ku-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 originally planned. Payload Specialist Scully-Powers, an employee of the U.S. Naval Research Laboratory, performed a series of oceanography observations during the mission. Garneau conducted experiments sponsored by the Canadian government, called CANEX, which were related to medical, atmospheric, climatic, materials and robotic sciences. A number of GAS canisters covering a wide variety of materials testing and physics were also flown. STS 41-G was an 8-day, 5-hour, 23-minute, 33-second mission which traveled 4.3 million miles and completed 132 orbits. It landed at the Shuttle Landing Facility at KSC -- the second Shuttle landing there -- on Oct. 13, at 12:26 p.m. EDT.