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id$THE SHUTTLE ERA:
   The reusable Space Transportation System marks a new
era for the space age. With the emergence of reusable
components, multi-million dollar throw-away boosters are
mostly a thing of the past.
   The Shuttle can best be described as a "space van"
designed to carry cargo into space. The Space Shuttle
costs about $35 million per flight and can carry up to
29,500 kg of payload as compared with the "expendable"
$25 million Delta rockets used to launch 5,000 pound
payloads during the late 1970's and early 1980's. In fact,
the Shuttle lifts 13 times as much as a Delta, at only a
50% increase in cost.
   The Orbiter is designed to last for one hundred flights
and is both a spacecraft and aircraft. It is about the size
of a DC-9 airliner and is launched with a combination of
solid and liquid rocket engines. The launch configuration
is centered around the External Tank (ET) which contains
fuel for the three Space Shuttle Main Engines (SSME's)
located at the base of the Orbiter. Attacked to the side
of the ET are a pair of Solid Rocket Boosters (SRB's) which
provide the majority of thrust for liftoff.
   The SSME's are the most advanced liquid-fuel rocket 
engines ever built. Each SSME has a rated thrust of 1.6
million newtons at sea level. Propellants for the SSME's
are contained in the ET and are fed into the Orbiter's aft
fuselage by two large conduits. The SRB's produce a total
of about 2.4 million newtons of thrust at liftoff.
   Two minutes into launch the SRB's are discarded and
land in the Ocean to be recovered for re-use. Eight
minutes into the flight, the ET is jettisoned over the Indian
Ocean and is the only shuttle component not retrieved for
re-use.


A BRIEF HISTORY:
   A Space Shuttle Task Group was formed at NASA in April
of 1969 to start Phase A, the conceptual stage of the
project. The Phase A plan was studied by a dozen
aerospace companies after which NASA held a preliminary
review at the Museum of Natural History in Washington in
October of 1969. Early in 1970 NASA released an artist's
impression of its new, winged spaceship, as it appeared
from the preliminary Phase B study. Because of budgetary
constraints, many beneficial compromises had to be made
thus delaying approval of the tree-element Shuttle
System by President Nixon on 5 January 1972.
   The decision to use twin, solid-propellant rocket
motors was settled in March of 1972 with Rockwell
International (then North American Rockwell Corporation)
as prime contractor. The program was to cost $2.6 billion
over six years for an envisioned program of 570 Shuttle
flights for the 1980's and 1990's.
   Testing of the first Orbiter, dubbed "Enterprise" at the
request of fans of the science fiction television series
"Star Trek", began at NASA's Dryden Flight Research
Center at Edwards AFB in February 1977. A sequence of
unmanned, then manned, captive flight tests was
conducted. On 12 August 1977, manned free-flight tests
began when Fred W. Haise and C. Gordon Fullerton flew the
75-ton glider around a U-shaped course to a flawless
landing after it had separated from the specially modified
747 aircraft at 6,950 meters. How the Orbiter would
handle in the high atmosphere at hypersonic velocity only
an orbial test-flight would tell. The approach and landing
tests at Edwards ended in October of 1977. Orbiter
"Enterprise" was then sent to Marshall Space Flight Center
in Huntsville, Alabama for eight months of structural
vibration tests.
   The Shuttle was scheduled to make its first manned
test flight in March of 1978. A series of problems
developed which delayed the project until early 1981.
An initial launch date of 10 April 1981 for the Orbiter
"Columbia" was set by NASA, though it was not until
April 12, at 7.00.03.98 am EST did she lift off from Launch
Comples 39A at Kennedy Space Center in Florida. The
initial setback was caused by computer communications
problems. Commanding the first Shuttle launch was John
W. Young with Capt. Robert L. Crippen as pilot. Columbia
made a safe re-entry on 14 April, with only a few missing
tiles after flying from a Mach 25 orbital velocity through
a 8,148 km glide to a perfect touchdown on Runway 23,
Edwards AFB, California, just 54 hours and 22 minutes
after lift-off.


Five Orbiters have been built:
Challenger OV-099 ** Was a test vehicle, lost 1/28/86.
Enterprise OV-101 ** Test vehicle, non flyable.
Columbia   OV-102
Discovery  OV-103
Atlantis   OV-104

** ORBITER DIMENSIONS **
Length:             37.24 meters
Height:             17.27 meters
Wingspan:           23.79 meters
Cargo Bay:          18.3 x 4.6 meters
Weight (empty):     75,000 kg
Lift-off weight:    2,040.816 kg


** EXTERNAL TANK DIMENSIONS **
Length:             47 meters
Diameter:           8.38 meters
Weight (empty):     35,400 kg
Lift-off weight:    743,253 kg

** SOLID ROCKET BOOSTER DIMENSIONS **
Length:             45.5 meters
Diameter:           3.7 meters
Weight at launch:   586,506 kg
Thrust at launch:   11,800,000 newtons


** OVERALL STS DIMENSIONS **
Length:             56.1 meters
Height:             23.4 meters
Lift-off weight:    2,040,816 kg

** SPEEDS **
@T+0:00:50          Mach 1.0
@T+0:02:12          Mach 4.5
@T+0:06:30          Mach 23.5


** SHUTTLE ALTITUDE LIMITS **
Low Orbit:          240 km      Maximum payload
Standard Orbit:     400 km      Normal payload
Maximum Orbit:      1,100 km    Minimal payload

** ORIBTER MATERIALS **
Aluminum is the major structural material, used with
boron and kevlar where appropriate. The bay doors are a
graphite/epoxy composite. Thermal protection is provided
by four types of materials:
1. Coated Reinforced Carbon-Carbon (RCC is a graphite
cloth chemically converted silicon carbide).
2. High-temperature Reusable Surface Insulation (HRSI is
formed silicia formed by ceramic bonding).
3. Low-temperature Reusable Surface Insulation (LRSI is
basically the same as the HRSI, except for different
optical properties).
4. Flexible Reusable Surface Insulation (FRSI is coated
Nomex Felt). RCC is used on the nose caps and leading
edges (usually grey colored). HRSI tiles are black tiles,
while LRSI and FRSI show as white areas.


The ET uses a variety of foam coverings, the most
important being abalative, while its structure is aluminum.
The SRB's use the same materials, with some fiberglass in
key areas. The SRB structure is comprised of various
aluminum alloys.

