The third operational orbiter, Discovery (OV-103), is named after two famous sailing ships. Henry Hudson sailed in one in 1610/11, searching for a north-west passage between the Atlantic and Pacific Oceans, only to come across what became known as Hudson Bay. Discovery was also the name of Captain James Cook's ship on the voyage during which he discovered in 1778 what he called the Sandwich Islands, better known to us now as the Hawaiian islands. Discovery was delivered to the Kennedy Space Center in November 1983 and made its space debut on August 30 of the following year on STS-41D. During this mission three satellites were deployed, and among the crew of six Judy Resnik became the second American woman to travel in space. Discovery's second mission (STS-51A) was highlighted by the recovery of two disabled comsats, Palapa B2 and Westar VI, during some spectacular spacewalking by Joseph Allen and Dale Gardner. On its fourth flight (STS-51B) unscheduled spacewalking by Jeffrey Hoffman and David Griggs failed to activate the Leasat 3 comsat that refused to work after deployment. But pride was restored on Discovery's sixth flight (STS-51I) when William Fisher and James van Hoften carried out successful repairs on the satellite and sent it on its way. STS-51I took place in August/September 1985. Because of the grounding of the shuttle fleet following the Challenger disaster, Discovery did not make its next flight for three years. This mission, STS-26, marked the return to flight of the shuttle. Discovery was, as it were, the phoenix rising from the ashes of Challenger. As Discovery and the shuttle stack sat poised on the launch pad on September 29, 1988, they looked no different from earlier shuttles. But appearances were deceptive. In the wake of the Challenger accident more than 400 major and minor modifications had been made to shuttle systems. Over 150 changes had been made to the solid rocket boosters (SRBs) alone, to prevent a recurrence of the fault that precipitated the Challenger disaster. Changes were also made to the plumbing of the external tank and to the main engines. It was Discovery, however, which underwent the most extensive modifications, some 220 in all. The heat shield was upgraded in places, and the brakes, tyres and steering gear improved. The crew flew in new pressurized orange-coloured flight suits, each with oxygen tank, parachute and inflatable life raft. And a new emergency escape system was fitted, for use during a launch abort while the orbiter was in gliding flight. It took the form of a telescopic pole, along which the astronauts could slide and clear the orbiter prior to deploying parachutes. On September 29, 1988, Discovery blasted off the launch pad in spectacular fashion and conducted a textbook mission. When the orbiter touched down at Edwards Air Force Base on October 3, mission control at Houston observed: "A great ending to a new beginning." That it was. Since then Discovery has continued in the forefront of the exploration of space with the launch of the Hubble Space Telescope (STS-31), which is peering deep into the universe; the Ulysses space probe (STS-41), which is investigating the polar regions of the Sun; and the UARS (upper atmosphere research satellite, STS-48), which is closely monitoring the Earth's atmosphere, particularly with regard to ozone depletion.
