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Hampton, Virginia
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Last Update: February 10, 1998
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Experiment Title: Interaction of Atomic Oxygen With Solid Surfaces at Orbital Altitudes
Original Principal Investigator(s): Gregory, Dr. John C. - Invest. Role: Original, Gregory, Dr. John C. - Invest. Role: Present, Peters, Dr. Palmer - Invest. Role: Original, Peters, Dr. Palmer - Invest. Role: Present,
Experiment Description:Atomic oxygen and nitrogen are known to be extremely reactive when impinging on
solid surfaces. Chemical changes can occur which alter optical and electrical
properties and in some cases even remove layers of material. If the atoms
impinge with the kinetic energy of orbital velocity (approximately 5 eV for
atomic oxygen), the possibility of physical sputtering exists. There is,
however, no experimental evidence for this because laboratory beams of
sufficient flux at these energies are extremely difficult to produce.
The mechanisms for these interactions are not entirely. This experiment was
designed to expose a wide variety of surfaces to the intense atom flux in orbit
in order to determine the gross nature of the effects.
As a platform for this type of experiment, the LDEF is particularly well suited
compared with other spacecraft designed to point or remain fixed in space. The
attitude stabilization mode of LDEF resulted in the same surface always being
presented to the ambient atmospheric flux along the velocity factor, while the
opposite surface of the vehicle remained in a hard vacuum. Images produced by
pinhole cameras using film sensitive to atomic oxygen provide information on
the ratio of spacecraft orbital velocity to the most probable thermal speed of
oxygen atoms. Alternatively, information on the spacecraft attitude relative
to the orbital velocity can be obtained, provided that corrections are
properly made for thermal spreading and a co-rotating atmosphere.
Photograph Classification: Flight
Associated Photograph(s):
LaRC - L90-10416
KSC - None
JSC - S32-77-065
LaRC - L91-09090
KSC - KSC-390C-1558.02
JSC - None
LaRC - L84-07015
KSC - KSC-384C-15.01
JSC - None
LaRC - L90-13407
KSC - KSC-390C-1030.09
JSC - None
LaRC - L84-07005
KSC - KSC-384C-14.03
JSC - None
LaRC - L90-10451
KSC - None
JSC - S32-78-100
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