The second operational space shuttle orbiter, Challenger (OV- 099), started out as a high-fidelity test article, and underwent 11 months of extensive vibration testing. Then it was converted into a full flight vehicle. Challenger was named after a US Navel research vessel that plied the Atlantic and Pacific oceans in the 1870s. The Apollo 17 lunar module also carried the same name. Challenger was rolled out of Rockwell's Palmdale facility on the last day of June 1982 and was flown to the Kennedy Space Center a few days later. Problems with fuel leaks in the main engines and with the payload delayed its maiden flight from January until April 4, 1983. That flight, the sixth by the shuttle, was the first of only ten by Challenger. The tenth, in January 1986, ended in disaster when the orbiter was blasted apart in a catastrophic explosion shortly after lift-off. The flight crew of seven perished, the first US astronauts to do so in a space flight. During its brief lifetime, Challenger completed 987 orbits of the Earth and logged more than 69 days in space. It achieved some notable space firsts. Its maiden flight (STS-6) saw the deployment of the first tracking and data relay satellite (TDRS- 1), and the testing of the new shuttle spacesuits by Donald Peterson and Story Musgrave. On its second flight (STS-7) Sally Ride became the first American woman to fly in space. On the third (STS-8) Challenger made the first night launch and landing. On the fourth (STS-41B) Bruce McCandless became the first astronaut to spacewalk without a safety tether, flying in the MMU (manned manoeuvring unit) up to 30 metres away from the orbiter. The mission came to an exciting end when Challenger became the first orbiter to touch down at the Kennedy Space Center. The MMU was back in action on the next Challenger mission (STS- 41C) during spectacular spacewalking by George Nelson and James van Hoften to capture and repair the ailing Solar Max satellite. That mission also saw the deployment of the LDEF (long-duration exposure facility). Sally Ride made her second space flight on Challenger's sixth mission (STS-41G), along with Kathryn Sullivan, who became the first American woman to walk in space. Challenger carried Spacelab modules into space on its next three flights, in 1985. On STS-51B the Spacelab 3 crew was accompanied by two monkeys and 24 rodents. On STS-51F the Spacelab 2 pallet payload included an 'igloo' containing automatic control systems. An abort-to-orbit situation occurred on lift-off following premature shutdown of one main engine. On its last complete flight (STS-61A) Challenger carried Spacelab D1 on a mission dedicated to, and largely financed by, West Germany. It featured a record eight-astronaut crew. Challenger's tenth and what was destined to be its final mission (STS-51L) was dubbed the 'teacher's flight' because it included teacher Christa McAuliffe, who was scheduled to conduct the first lessons from space. But it was not to be. Just 73 seconds into the mission after what appeared to be a perfect lift-off on January 28, 1986, a fireball erupted around Challenger and the orbiter was blasted into pieces. In the conflagration the crew of seven perished. As well as Christa McAuliffe, the crew were Richard Scobee, Michael Smith, Judith Resnik, Ellison Onizuka, Ronald McNair and Gregory Jarvis. While the nation mourned and all shuttle flights were halted indefinitely, an intensive salvage operation went ahead to find what remained of Challenger from the waters off Cape Canaveral. Over the next seven months, nearly half of the orbiter structure was located and recovered. After analysis, the mangled remains of the magnificent flying machine Challenger were transported to an abandoned Minuteman missile complex on Cape Canaveral Air Force Station and placed in storage there. They serve as a reminder of the ever-present danger that attends all those who dare to venture into space.
