The final design of the space shuttle, which is still used today, was designed to carry between five and seven astronauts, and was to be used for approximately 100 launches, or 10 years by the program. The first completed, fully functional NASA space shuttle was the Columbia, which made her debut at the Kennedy Space Center in Florida on March 25, 1979. Columbia was launched for the first time on April 12, 1981. Other space shuttles to follow included Challenger in 1982, Discovery in 1983, Atlantis in 1985 and Endeavour in 1991. Challenger was lost when it exploded during ascent on January 28, 1986, killing all seven astronauts aboard. Seventeen years later on February 1, 2003, the Columbia space shuttle was destroyed when it disintegrated during reentry, again killing all seven crew members on board. Space shuttles still in active use by NASA today include Atlantis, Discovery and Endeavour. Enterprise, Pathfinder, and Explorer are all full-scale replicas of other active space shuttles, but were built for display and test flights only, and have never actually entered orbit.