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Officially designed the
"Space Transportation System," (STS) America's current space workhorse consists
of three components: a large external tank to hold fuel; two solid rocket boosters; and
the Orbiter, which is the space vehicle that holds the crew. The term "Space
Shuttle" applies to the entire system, but is often used to identify just the
Orbiter.
Once the Moon Race had been won, NASA sought Congressional
approval for an STS as the first step to establishing a permanent space station. The
Space Shuttle would be used to ferry people and supplies; it would function as an orbiting
scientific laboratory; and provide the means the place satellites in orbit, then
later repair and recover them.
Approval was granted in 1972 and the first flight occurred in 1981.
The Orbiter looks much like an airplane and is about the size of
a DC-9 jet airplane. Total height is about 184 feet, about half that of the tall,
slim Saturn V rocket; Wingspan is about 78 feet. With the exception of its
windows the entire Orbiter is covered with insulation to protect it from the heat
generated during reentry. On the underside, where reentry heat is extreme, there around
23,000 individual ceramic coated, silica fiber tiles that prevent it from being
incinerated over the course of dozens of reentry's.
Unlike other rockets before them, which lifted off slowly and seemingly
reluctantly, the Space Shuttle leaves the launch pad within three seconds after ignition.
A thrust of almost six million pounds is delivered by the solid rockets with over another
million pounds created by the main engines. About two minutes after liftoff, the
solid rocket boosters burn out and falls away. About eight minutes later, the larger
external tank separates and falls away. |
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