Preliminary structural evaluation and design of the HL-20

A lifting body concept, the HL-20, was designed at NASA Langley Research Center, and a structural analysis of the configuration with a cylindrical pressurized welded aluminum alloy 2219 crew cabin was presented. Loads for the vehicle were assembled from mission loading conditions such as abort, on-orbit pressurization, blast overpressure, aerodynamic maneuver, and touchdown. The critical loading conditions were identified, and resultant loads were mapped onto the structure in order to review the effects of the mission loading conditions. The HL-20 structural concept was sized for the mission loads, and the resulting structural weights were calculated. Carbon--carbon and graphite/polyimide honeycomb heat shields are discussed.