Long duration exposure facility LDEF

There are elements of the space environment that make it harsh on materials that are employed in space. The presence of atomic oxygen and the ever-present ultraviolet rays of the sun are dominant. Some of the very best scientific data on the survivability of materials in space come from experiments conducted on NASA s Long-Duration Exposure Facility (LDEF). Summaries of those data (7,5) reveal that atomic oxygen may be a major problem for materials that deteriorate upon oxidation. Most dramatic among the LDEF samples was the erosion of exposed carbon surfaces owing to the loss of surface carbon as CO and CO2. These results became design considerations. 

In order to study the effects of space environment on different materials, including polymers [326, 450, 1326, 2314], NASA s Office of Aeronautics and Space Technology launched, in 1984, the Long Duration Exposure Facility (LDEF) unmanned, free-ffying spacecraft (Fig. 9.9) for long term (69 months) exposure to the space environment [1198, 1632]. 

LDEF long duration exposure facility LOI limiting oxygen index... 

Fig. 9.9. NASA Long Duration Exposure Facility, unmanned, free-flying spacecraft. (Reproduced with permission from LDEF-69 Months in space, conference publication 3134, part 1 published by NASA.)...

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