Space shuttle

The Space shuttle was a type of early space vessels used by humans on Earth during the late 20th and early 21st centuries. Designed and built by the United States of America's NASA space agency, the shuttle played an important role in humanity's early exploration of space.

The space shuttle was composed of three components, a reusable orbiter, a large fuel tank, and two booster rockets. After launch the fuel tank and the booster rockets would be jettisoned, and the orbiter would orbit the Earth. After the completion of the mission, the orbiter would reenter the atmosphere and land like an airplane.

Over the years, the United States constructed six of these shuttles, which were;
 * Enterprise (OV-101) - The prototype vehicle. As a test vehicle, this shuttle was not built to actually enter orbit, but was instead used to test the viability of certain systems - such as the landing gear.  NASA briefly considered making the orbiter functional after the Challenger was destroyed, but instead decided to build a new shuttle to replace Challenger.
 * Columbia (OV-102) - The second shuttle, and the first shuttle that was actually functional. The Columbia was destroyed in 2005 when it broke up upon reentering Earth's atmosphere.
 * Challenger (OV-099) - The third shuttle built. This shuttle was destroyed in 1985 when it exploded shortly after takeoff.  The USS Challenger (NCC-71099) was built to honor this orbiter.
 * Discovery (OV-103)
 * Atlantis (OV-104)
 * Endeavour (OV-105) - This shuttle was built to replace Challenger.