a spacecraft designed to be used, for example, for travelling between the earth and a space station See related entries: Aircraft, Space travel Culture Space shuttles are part of the US Space Transportation System (STS), and the flights began in 1981. The first four were Columbia, Challenger, Discovery and Atlantis. When Challenger exploded in 1986 killing all seven of its crew, all flights were stopped for more than two years. Endeavor replaced Challenger in 1992. In 2003 Columbia exploded while re-entering the earth's atmosphere and again all flights were stopped. In 2004 the US announced that it will replace the space shuttle with a new type of vehicle by 2010.