STS-41B: FIRST UNTETHERED EVA - FIRST KENNEDY LANDING
This, Challenger's fourth and the shuttle's tenth flight, began on February 3, 1984. It was referred to as flight 41B under a new system of designation NASA had adopted. The '4' stood for 1984, the fiscal year of launch; the '1', for the Kennedy launch site; and the 'B', because it was the second flight of fiscal year 1984. (As time went on this system became increasingly confusing because the fiscal year does not coincide with the calendar year; also flights began to be swapped round! Since the return to flight after the Challenger disaster, missions have been designated by a simple STS number. But these are not necessarily in sequence!) STS-41B was initially written off as a failure by the 'shuttle- bashing' popular press. But it was through no fault of the shuttle system that the two satellites Challenger deployed, Westar VI and Palapa B2, failed to reach their proper geostationary orbits. The faults lay in the PAM (payload assist module) boosters that should have lifted them to high orbit. So it was in urgent need of success that the crew embarked on the next part of the mission, a test flight of the manned manoeuvring unit, or MMU. This jet-propelled backpack is designed to enable spacewalking astronauts to move about freely in space. On February 7 Bruce McCandless donned the MMU and, operating its thrusters, gently jetted out of Challenger's payload bay. He became the first human satellite, the first astronaut to venture on EVA without a safety tether. As he left the bay, he said: "That may have been one small step for Neil, but it's a heck of a big leap for me!", making reference to Neil Armstrong's famous words as he stepped down onto the Moon from the Apollo 11 lunar module in July 1969. Gaining confidence, McCandless gradually flew out to 45 metres from Challenger, then returned. He was then given the go-ahead to venture to more than twice that distance, becoming a tiny white speck against the inky blackness of space. When he returned, he floated in front of Challenger's windshield, asking commander Vance Brand: "Hey, you going to want the windows washed while I'm out here?" McCandless then turned the MMU over to his colleague Robert Stewart, who finally flew out to a distance of 93 metres from the orbiter. Meanwhile McCandless was checking out a mobile foot restraint, a platform that fixed to the end of the RMS (remote manipulator system) arm. Nicknamed the 'cherry picker', it was designed to carry astronauts around the payload bay when carrying out activities, such as the satellite repair work planned for Challenger's next mission (the Solar Max repair). These first flights of the MMU were spectacularly successful. McCandless and Stewart, who flew the MMU again on February 9, delighted in the experience. "They call each other Flash Gordon and Buck Rogers", reported commander Brand, referring to the fictional space heroes. A further triumph was to come for Challenger. On February 11 the weather was perfect at the Kennedy Space Center for the orbiter to attempt the first landing there at the long shuttle landing facility. After de-orbiting over the Pacific Ocean, it crossed the Baja Peninsula, Mexico and Texas, and entered Florida travelling due east. It trailed a double sonic boom behind it across the State, going subsonic as it neared Kennedy. After a final turn out to sea, Challenger lined up for its final approach and made a perfect touchdown on the 5-km long runway. It was the first time any spacecraft had returned to its launch site. This not only saved time, but also some $1 million in transport costs from other landing sites.
