
A re-usable crewed launch vehicle. The
first-generation US shuttle launched in April 1981, managed by
NASA's Johnson and Marshall Space Centers. The first Soviet
shuttle, Buran, was launched in November 1988 for a single test
flight without crew, using the Energiya booster. The European Space
Agency shuttle Hermes programme was cancelled after several years'
development.
The US shuttle carries up to
seven crew, and is capable of launching a 24 400-kg / 53 700-lb
payload into low Earth orbit; missions are up to 14 days' duration.
It comprises a delta-winged lifting body orbiter with main engines,
a jettisonable external fuel tank, and two auxiliary solid rocket
boosters. The fleet comprises four vehicles: Columbia, Discovery,
Atlantis, and Endeavour.
It has been successfully used
to launch numerous science and applications satellites and on-
board experiments, to carry the Spacelab module, and to retrieve
spacecraft from orbit. The Challenger explosion on the 25th flight
(28 Jan 1986) 73 sec after launch caused the loss of the crew. The
first reflight took place in September 1988, and a replacement
orbiter, Endeavour, became operational in May 1992.
The Space Shuttle is a reusable rocket-launched
vehicle designed to transport people and cargo between Earth and
orbiting spacecraft, and then to return to the Earth's surface by
gliding down and landing on a runway. A Space Shuttle consists of a
reusable delta-winged spaceplane, called an orbiter; two
solid-propellant booster rockets, which are recovered and also
reused; and an expendable tank containing liquid propellant for the
orbiter�s three main engines. Only the orbiters have names,
and an orbiter alone is not a full Space Shuttle.
The Shuttle was selected in the early 1970s as
the principal space launcher and carrier vehicle to be developed by
the National Aeronautics and Space Administration (NASA). Planned
as a replacement for expensive, expendable booster rockets, it
would complete NASA's new Space Transportation System (STS). The
program finally got under way in the early 1980s.

The shuttle takes off from the Kennedy
Space Center in Florida and usually lands at Kennedy. It is carried
into space on the back of a powerful liquid-fuel rocket, with a
second pair of solid-rocket boosters strapped onto the sides. The
shuttle lands like a conventional aircraft, though it depends
heavily on sophisticated computers, software, and skilled pilots.
There is little room for error and no second chances; at 10,000
feet high and 25 miles from touchdown, it must already be in the
glide slope and centred precisely on the runway to make a proper
landing.

The Space Shuttle was developed by the
National Aeronautics and Space Administration. NASA coordinates and
manages the Space Transportation System (NASA's name for the
overall Shuttle program), including intergovernmental agency
requirements and international and joint projects. NASA also
oversees the launch and space flight requirements for civilian and
commercial use.
The first shuttle was Columbia, launched on April
12, 1981. It broke up shortly before a scheduled landing, on
February 1st, 2003.

The Space Shuttle system consists of four
primary elements:
- a winged
orbiter that carries both crew and cargo;
- three
Space Shuttle main engines;
- an
external tank containing liquid hydrogen (fuel) and liquid oxygen
(oxidizer) for the orbiter's three main rocket engines; and
- a pair
of large, solid-propellant, strap-on booster rockets (Solid Rocket
Boosters (SRBs))

At lift-off, the entire system weighs
4,400,000 pounds (2,000,000 kilograms) and stands 184 feet (56
metres) high. During launch the boosters and the orbiter's main
engines fire together, producing 7,000,000 pounds (31,000,000
newtons) of thrust.

After two minutes of flight a Space Shuttle
reaches an altitude of 32 miles (48 kilometers) and the boosters
have burned all their propellant. They then detach and parachute
into the ocean. Two waiting ships recover them, for refurbishment
and reuse on later missions. After the orbiter has exhausted the
propellants in the external tank upon attaining 99 percent orbital
velocity, it releases the structure, which disintegrates while
falling through the atmosphere.

The orbiter and external tank continue on
toward Earth orbit. When the orbiter�s main engines cut off,
just before achieving orbit, the external tank is jettisoned, to
re-enter the atmosphere and break up over a remote ocean area. On
most missions the orbiter continues to coast until it reaches the
other side of the Earth from where the external tank was discarded.
The on-board orbital maneuvering engines are then fired to place
the vehicle in a near- circular low-Earth orbit. Most operational
missions last from four to seven days, though longer ones are
sometimes required.

The first Space Shuttle lifted off from
Pad A on Launch Complex 39, Kennedy Space Center, on April 12,
1981. After a two-day, test-flight mission that verified the
ability of the Orbiter Columbia to function in space, it landed at
Edwards AFB in California. The vehicle was piloted by John Young
and Robert Crippen. The STS-1 mission marked the first time that a
new space vehicle carried a crew on its initial flight.
An assembled Space Shuttle is approximately 184
feet (56 meters) long, 76 feet (23 meters) high to the tip of the
orbiter�s vertical tail, and 78 feet (24 meters) wide,
measuring across the orbiter�s wingtips. Liftoff weight is
usually about 4,500,000 pounds (2,041,200 kilograms).
An orbiter's three liquid fueled engines --
drawing propellants from the external tank -- and the two
solid-propellant rocket boosters burn simultaneously for the first
two minutes. Together, they produce about 7.3 million pounds (32.4
million newtons) of thrust at liftoff.
When the mission has been completed, the orbiter
re-enters the atmosphere and returns to Earth, gliding to an
unpowered landing at either KSC or Edwards AFB.