My Science School

After extensive preparation, the STS lift off from the launch tower. After eight seconds, the rocket is travelling at 160km/h (100mph), but it only takes one minute to reach 1600km/h (1000mph). At a height of 45km (28 miles), the solid rocket boosters are jettisoned. They fall back to Earth, using parachutes. When the fuel in the external tank is used up, it too is jettisoned, burning up in Earth's atmosphere. Once the orbiter reaches a low-Earth orbit, it stays there for up to two weeks before beginning the dangerous return trip.

The space shuttle was developed by the National Aeronautics and Space Administration, more commonly known as NASA. The vehicle consists of a winged orbiter, two solid-rocket boosters, and an external fuel tank. As with previous spacecraft, the shuttle is launched from a vertical position. Liftoff thrust is derived from the orbiter's three main liquid-propellant engines and the boosters. After two minutes, the boosters use up their fuel, Separate from the Spacecraft, and after deployment of parachutes are recovered following splashdown. During this time, the speed of the shuttle is about 1400 meters per second.

After about eight minutes of flight, the orbiter's main engines shut down; the external tank is then jettisoned and burns up as it reenters the atmosphere. The orbiter meanwhile enters orbit after a short burn of its two small Orbiting Maneuvering System (OMS) engines. At this time, its top speed is an amazing 8,000 meters per second! To return to earth, the orbiter turns around, fires its OMS engines to reduce speed, and, after descending through the atmosphere lands like a glider.

After four orbital test flights (1981-1982) of the space shuttle Columbia, operational flights began in November of 1982. On January 28, 1986, a shuttle exploded shortly after takeoff, killing all seven astronauts. Shuttle flights were suspended until September 1988, while design problems were corrected, and then resumed on a more conservative schedule; NASA was forced to reemphasize expendable rockets to reduce the cost of placing payloads in space. By the end of 2000, 102 missions had been completed and five different orbiters had been seen in service.

Picture Credit : Google