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Progress in the area of precision segmented reflectors (PSR) for space applications has been driven by panel development activities. A number of small to medium size panels have been fabricated to demonstrate feasibility. The primary emphasis to date has been on making the panels lightweight and with high precision surfaces. Because of this emphasis, composite materials, and in particular, graphite fiber reinforced epoxy materials, were an obvious choice for construction of the panels. Indeed, many of the panels in existence have been fabricated from materials of this type. In terms of space applications, however, where stability and durability are of concern, it appears that these materials may not possess the balance of properties required for long term missions. Testing of these materials in simulated use environments has shown that they are deficient in either their thermomechanical properties, their stability (dimensional and environmental) or their fabricability. Recognizing that the development of new or modified materials for panel construction will be imperative if PSR technology is to be utilized in long term space missions, a program has been initiated to achieve this end. An initial set of material requirements has been developed based on a variety of mission scenarios. It is clear that no one material will be applicable to all such missions. Some potential candidate materials or generic classes of materials have been identified. Because of the basic requirements of light weight and stiffness, attention has continued to focus on advance composites. In the near term, it is likely that modified fiber reinforced organic matrix composites have good applicability. In the longer term materials such as carbon/carbon composites, graphite/glass composites and metal matrix composites may ultimately provide the best mix of properties. In this paper, information on PSR panel material requirements, as well as, test data on state-of-the-art materials will be presented. In addition, potential candidate alternate materials and progress toward their development will be discussed.
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