Despite these tragedies, the Space Shuttle program achieved many noteworthy successes, including the launch and repair of the Hubble Space Telescope, the construction of the International Space Station (ISS), and numerous scientific experiments conducted in space. The program was officially retired in 2011, marking the end of an era in American space exploration.
However, the program is perhaps best known for two tragic disasters - the Challenger explosion in 1986, and the Columbia disaster in 2003, both of which resulted in the loss of the entire crew. These incidents highlighted the risks of human spaceflight and led to significant design and operational changes.
The fleet was composed of five orbital-class vehicles: Columbia, Challenger, Discovery, Atlantis, and Endeavour. Each shuttle was designed to fly multiple missions and then be refurbished and flown again, creating a more cost-effective form of space travel.
The US Space Shuttle program, officially called the Space Transportation System (STS), was NASA's iconic human spaceflight program, running from 1981 to 2011. The program's primary goals were to carry large payloads to and from Earth's orbit, to provide a reusable vehicle for human space exploration, and to conduct scientific research aboard the shuttle.