SEEN SEE
E.R
loads in the Orbitar cargo bay. The harsh environments of this bay are gen-
erally divided into either natural or induced environments. The prelaunch
and post landing are considered natural and the induced environments are
those that exist during launch, pre-entry, and landing. On-orbit may be
either. The natural ground and induced environments (more or less controlled)
are not considered extreme. The natural space environments much to the con-
trary pose problems to design. Pressure, is one such prob] em and at 500
nautical miles (926 km) itiis 4.7 x10 torr (9.1 x 10 psi). Solar
radiation (thermal) is another problem and this orbital altitude is rated
at 443.7 Btu/ft2/hr while the earth's albedo is 30% of the solar radiation.
This, of course, occurs at many levels as the satellite orbits the earth
but only the worst case is tested to assure survival of equipment and integrity
Of intelligence acquired.
Film is an especially sensitive problem since under normal conditions, for a
seven to twenty day mission, environmental enclosures and spacecraft structure
give sufficient shielding. On Skylab, for instance, the film vault was the
size of a home freezer with solid aluminum walls several inches thick. This
was found to be adequately protective against the natural radiation environ-
ment of terrestrial space which consists of (1) galactic cosmic radiation
(mainly protons), (2) geomagnetically trapped radiation, and (3) solar flare
particle events.
The system qualification test include the functional tests, temperature control,
EMC/EMI, vibration, dynamic resolution, and thermal vacuum which includes
static and dynamic resolution. Following these exhaustive tests there is a
high rating of confidence that the space camera will acquire good imagery.
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