The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to the Department of Defense. Executive ABSTRACTThe Aerospace Corporation was tasked by the Volpe National Transportation Systems Center to provide technical support to the Federal Aviation Administration, Office of Commercial Space Transportation (FAA/AST), in developing guidance for AST and industry use on operational limitations and inspection requirements for suborbital reusable launch vehicles (RLVs) built using composite structures and subjected to a typical flight profile. Four representative suborbital flight profiles were selected from a previous study. A review of the literature was conducted, which included peerreviewed journal articles, conference proceedings, and standards set forth by NASA, AIAA, and ASTM, with the goal of identifying the operational environment phenomena, and their adverse effects on fiber-reinforced polymer matrix composites, and also considerations for maintenance of composites, including lessons learned in the use of composites by the aviation community. Additional contributions were obtained from interviews with various subject-matter experts at The Aerospace Corporation. Environmental phenomena, their adverse effects on composite structure, and mitigation techniques, were identified. The phenomena were not ranked, in part due to lack of substantiated and uniform fidelity and maturity of data for each, but also due to the potential for synergistic effects and for environment coupling. Additionally, further study and data are necessary to understand the influence of exposure time on the effects of these phenomena, and also the severity of their effect at a representative suborbital altitude. A substantial list of references is provided for further reading. SUBJECT TERMS AbstractThe Aerospace Corporation was tasked by the Volpe National Transportation Systems Center to provide technical support to the Federal Aviation Administration, Office of Commercial Space Transportation (FAA/AST), in developing guidance for AST and industry use on operational limitations and inspection requirements for suborbital reusable launch vehicles (RLVs) built using composite structures and subjected to a typical flight profile. Four representative suborbital flight profiles were selected from a previous study. A review of the literature was conducted, which included peer-reviewed journal articles, conference proceedings, and standards set forth by NASA, AIAA, and ASTM, with the goal of identifying the operational environment phenomena, and their adverse effects on fiber-reinforced polymer matrix composites, and also considerations for maintenance of composites, incl...