The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

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The core vehicle in NASA’s space transportation
system program and the only American craft used
to carry humans into space since the Apollo-Soyuz
Test Project. Each Space Shuttle consists of an
Orbiter (of which four are in service), an External
Tank (ET), two Solid Rocket Boosters (SRBs), and the
Space Shuttle Main Engines (SSMEs). All these components
are reusable except for the External Tank.
Designed to operate on land, in the atmosphere, and
in space, the Shuttle combines features of a rocket, an
aircraft, and a glider. No other flying machine is
launched, serves as a crew habitat and cargo carrier,
maneuvers in orbit, then returns from space for an
unpowered landing on a runway, and is ready to fly
again within a few weeks or months. Its main engines
and solid rocket motors are the first ever designed for
use on multiple missions.
The Space Shuttle can take up to eight astronauts
into low Earth orbit to carry out a wide variety of
tasks, from satellite launching to construction of the
International Space Station, on missions lasting up
to two and a half weeks. It is used to support research
in astronomy, biology, space medicine, and materials
processing, and has delivered into orbit scientific,
commercial, and military satellites and interplanetary
probes. The Shuttle has also been used to carry Spacelab
and to repair, refurbish, or recover satellites. Since
the first launch on April 12, 1981—20 years to the day
after Yuri Gagarin’s historic flight—Shuttles have
flown two to nine missions a year, except in 1986 and
1987, when flights were suspended following the Challenger
disaster. Although its cost has proven much
greater and its practical launch frequency much lower
than originally anticipated, it represents a giant leap
forward in manned spaceflight capability.
The Shuttle travels from the Vehicle Assembly
Building at Kennedy Space Center (KSC), where its
main components are put together, to its launch pad
on a giant crawler-transporter vehicle—a trip that, at
a maximum speed of 1.6 km/hr, takes about five
hours. Launch complexes 39A and 39B were originally
used for the Apollo missions and renovated for
the Shuttle. A third intended Shuttle launch site built
at Vandenberg Air Force Base, California, by renovating
Titan III launch complex SLC-6 (nicknamed
“Slick-6”), has never been employed.
Space Shuttle
History
Born in 1968 at the height of the Apollo program, the
Shuttle was designed to provide NASA with an efficient,
reusable method of carrying astronauts to and
from a large, permanently manned space station (with
a crew of 12 to 24), and a multipurpose satellite
launch system with the potential to replace Atlas-
Centaur, Delta, and Titan rockets. Originally slated to
enter service by 1977, the Shuttle made its first spaceflight
in 1981 following numerous design changes.
At the outset, NASA envisaged a two-stage Shuttle
with a smaller manned winged vehicle (the Orbiter)
riding piggyback on a larger manned winged vehicle
(the Booster). These would be pad-launched from a
vertical position. The Booster would carry the Orbiter
to a height of about 80 km, at which point the Orbiter
would separate and fire its own engines to reach orbit.
The Booster—essentially a winged fuel tank—would
immediately descend and land near the launch site,
while the Orbiter would return at the end of its mission.
As described by NASA in 1970, this two-stage
Shuttle would be able to carry a 11,300-kg payload to
a maximum 480-km circular orbit.
In a time of recession, it soon became clear that
NASA could not afford a fleet of complicated twostage
Shuttles together with a space station. Furthermore,
although military funding for the Shuttle was
vital, the Air Force specified a payload capability
nearly three times what NASA had in mind. These
factors led to a dramatic redesign of both the Shuttle
and the proposed space station. From a Skylab-like,
single-structure station to be launched by a Saturn V
and serviced by the Shuttle, NASA switched to a
modular concept: the space station would be built
over several years from separate, Shuttle-launched elements.
This not only spread the financial outlay over
a longer period, it meant that the more powerful
Shuttle required would be able to carry heavy military
payloads. The redesign would also allow NASA to
secure private funding to carry commercial satellites
aboard Shuttles while cutting costs by phasing out the
Atlas, Delta, and Titan fleets. With an event like the
Challenger disaster never anticipated, NASA put all of
its eggs in one basket: the Shuttle would become the
Agency’s sole medium-to-heavy launcher into the