Space Transportation System

The Space Transportation System (STS) is a term often used synonymously with the Space Shuttle program, a United States government initiative that was operational from 1981 to 2011. The STS was the world's first reusable spacecraft system, designed to carry astronauts and cargo to and from Earth's orbit. The system was composed of three main parts: the Space Shuttle orbiter, which housed the crew and payload; the solid rocket boosters, which provided most of the Shuttle's lift during the first two minutes of flight; and the external tank, which carried fuel for the orbiter's three main engines. The STS was used for a variety of missions, including satellite deployment, space science experiments, and construction and servicing of the International Space Station. Despite its many successes, the STS program also experienced two tragic accidents, the Challenger and Columbia disasters, which resulted in the loss of 14 astronauts.