Feasibility Study of Endo- and Exo-skeletal Framed Structures with Envelopes for LTA Platforms

14. ABSTRACT 16. SECURITY CLASSIFICATION OF: A pathway for design and fabrication of Endo- and Exoskeleton framed elliptical envelopes was demonstrated. Envelope sizes of 2 ft x 0.5 ft and 5 ft x 1.25 ft were successfully fabricated and their buoyancy and lifting capability were assessed. A technique of filling the envelope with helium was demonstrated. The weight of 2 ft by 0.5 ft envelope before and after filling with helium was 0.082 lb (37 g) and 0.018 lb (8 g), respectively. Using the concepts developed for the 2ft x 0.5ft envelope, the fabrication was successfully scaled to 5 ft x 1.25 ft. The weight 1. REPORT DATE (DD-MM-YYYY)