Photograph courtesy NASA
Space shuttle Columbia, seen here launching in 1993, paved a brilliant legacy before its tragic end. The shuttle disintegrated over east Texas on its landing descent to Kennedy Space Center on February 1, 2003, at the conclusion of a microgravity research mission. Columbia was the oldest orbiter in the fleet and the first shuttle to orbit Earth. It was also the heaviest, weighing 178,000 pounds (80,800 kilograms).