Aerodynamic Deployable Decelerator Performance-Evaluation Program : Phase 2

Author / Creator

Bloetscher, E., author

Available as

Online

Summary

The Aerodynamic Deployable Decelerator Performance-Evaluation Program (ADDPEP) aims to advance the state of the art by developing the most effective analytical and empirical techniques for designin...

The Aerodynamic Deployable Decelerator Performance-Evaluation Program (ADDPEP) aims to advance the state of the art by developing the most effective analytical and empirical techniques for designing aerodynamic deployable decelerators and for evaluating these engineering techniques through wind-tunnel and free-flight tests. During ADDPEP Phase 2, two types of decelerators were investigated: large reefed supersonic parachutes and raminflated balloon-type BALLUTEs. The areas investigated included analytical and engineering design, material capabilities, fabrication techniques, and wind-tunnel and free-flight tests. Free-flight tests were performed on a hemisflo parachute having a nominal 16-ft-diameter canopy, a 10-percent extended skirt, and a 14-percent porosity. This design was tested for 200,000-lb opening loads, deployment Mach numbers were 1.50, 1.63, and 1.84 at altitudes of 13,700, 15,500, and 10,500 ft, respectively. The results confirmed that this parachute has excellent aerodynamic characteristics and adequate strength. Five-foot-diameter BALLUTEs, both textile and metal, were fabricated. These were designed for a broad spectrum of deployment conditions ranging from Mach 2.7 at 73,000 ft to Mach 10 at 225,000 ft. The textile BALLUTEs were wind-tunnel and free-flight tested; the metal BALLUTEs were wind-tunnel tested only. Flight tests were limited to Mach 9.7, and wind-tunnel tests to Mach 3. The flight test data supported wind-tunnel data, which indicated that excellent stability and structurally adequate designs can be attained with five-foot-diameter BALLUTEs.

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