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Last Update: February 10, 1998
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Experiment Title: Effects of Solar Radiation on Glasses
Original Principal Investigator(s): Whitaker, Dr. Ann F. - Invest. Role: Present, Whitaker, Dr. Ann F. - Invest. Role: Original, Kinser, Dr. Donald - Invest. Role: Present, Whitaker, Dr. Ann F. - Invest. Role: Present, Kinser, Dr. Donald - Invest. Role: Original, Whitaker, Dr. Ann F. - Invest. Role: Original, Mendenhall, Dr. Marcus - Invest. Role: Present, Nichols, Mr. Ronald - Invest. Role: Original, Nichols, Mr. Ronald - Invest. Role: Present, Wiedlocher, Mr. David - Invest. Role: Present, Tucker, Dr. Dennis - Invest. Role: Present, Weller, Prof. Robert - Invest. Role: Present,
Experiment Description:Damage of glass in space systems by space debris and micrometeoroids is of
interest due to the susceptibility of glass to catastrophic fracture under
impact load. The Gemini window impact and simulated meteoroid impact failures
in Orbiter windows indicate possible catastrophic effects of impact events in
space. Lunar soil samples collected during the Apollo 11 mission reveal
micrometeoroid impacts in glass spheres formed from the ejecta of larger
meteoroid impacts. Impacts in such glasses exhibit central melt regions sur-
rounded by fracture zones and spall areas. The influence of debris or
micrometeorite impacts on mechanical properties of glass determine, in part,
their sensitivity to the space environment.
The deterioration of glass when subjected to solar radiation has been
scientifically observed. Since glass is in a metastable state, this is not an
unexpected event; the glass would achieve a lower state of energy if its atoms
were rearranged in a long-range repetitious lattice structure. Changes in the
properties of a glass are commonly associated with exposure to solar
radiation. Because of insufficient test data for glasses exposed to actual
space radiation, the materials engineer must attempt to extrapolate from data
for artificial solar radiation exposure in order to select glasses for use in
hardware that were exposed to the space environment for long periods of time.
This limitation severely degrades the confidence level for the performance of
glasses utilized in space.
Photograph Classification: Flight
Associated Photograph(s):
LaRC - L90-10388
KSC - None
JSC - S32-76-054
LaRC - L84-07165
KSC - KSC-384C-317.08
JSC - None
LaRC - L91-11718
KSC - KSC-390C-1997.02
JSC - None
LaRC - L84-07158
KSC - KSC-384C-317.01
JSC - None
LaRC - L92-17662
KSC - KSC-390C-731.11
JSC - None
LaRC - L90-10495
KSC - None
JSC - S32-89-013
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