Carbon (graphite) fibers that are contained in composites have had a profound influence on the aerospace industry for the past decade or more. Today, these fibers are used in commercial and military aircrafts, in the nose cap and the leading edge of the shuttle, and made possible the nonstop circumvention of the earth by the very light weight aircraft, Voyager.
Carbon fibers will become even more important in future advancements of aerospace technology depending on the abilities of researchers to overcome technical barriers, engineers to apply these materials and producers to make them on a cost-effective basis.
Space applications are expected to be a major growth area, but special engineering and environmental requirements must be met. To do so means carbon-fiber-filled composites must not only have very high specific strength and stiffness properties, but they must be able to withstand a variety of new and different conditions such as multiple thermal cycles per day between 250°F (121'C) and -250°F (-157"C), solar radiation effects and atomic oxygen erosion at lower orbits. All of these effects to composites must be understood for flights that last for years rather than days or minutes. Such conditions represent real challenges to the scientists and engineers.
Fortunately, today there are available more alternatives for solutions to these problems than there have been in the past. For example, there exist graphite fibers with moduli approaching the theoretical value of 140 mpsi and strengths in excess of 700 kpsi. But the evolution of these high-Perotante fibers has progressed much further than our ability to effectively utilize and translate their properties into composite properties. However, it is expected that this challenge will be addressed by future research emphasis. Also, there are alternative matrices that include a spectrum of properties that are derived from polymers, metals and carbons. Each of these composite systems has its own advantages and disadvantages.
This means their constitutive properties must be understood in order to select the proper combination of fibers and matrix for a particular engineering or environmental problem.