The Effects of Space Environment on Structural Materials 660675
The early estimations of spacecraft engineers concerning potential degradation of structural materials in the space environment have not been as extensive as was first believed. In general, the mechanical properties of bulk structural metals are very little affected by the space environment except, of course, for the probability of penetration by meteoroids. The fatigue life of flexed structural materials in simulated space vacuum has been studied and it has been shown by some investigators that fatigue life is decreased. However, other studies have shown that the reverse is true.
The very thin plastic film structures such as the balloon satellites could be more susceptible to damage by the space environment. The successful performance of the Echo 1 satellite, however, has indicated some resistance to the deleterious effects of the space orbital environment by these materials. The development of the polyvinylidene films has resulted in a material more resistant to vacuum ultra-violet degradation than the polyethylene terephthalate previously used.
However, the planning of programs for longed lived satellites (of the order of 1 year in space), multimanned satellites, manned space stations, missions, manned and unmanned, to the moon and planets, and orbiting astronomical observatories, have imposed more exacting demands upon the reliability of the properties of materials for aerospace applications.