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.

This report contains the proceedings of the Retardation and Recovery Symposium sponsored by the Aeronautical Systems Division on 13 and 14 November 1962. The Introductory Session was opened with the Keynote Address which reviewed the use and applications of deployable aerodynamic decelerators throughout the past fifty (50) years and noted the areas in which additional work had to be accomplished. The four Technical Sessions deal with the latest significant developments in the retardation and recovery area. The Technical Sessions begin with presentations and discussions of investigations in the hypersonic and supersonic flight regimes followed by a technical analysis of transonic and supersonic flow phenomena. In addition, new aerodynamic decelerator designs and discussion of the wind tunnel tests pertaining to these designs, as well as overall reliability of recovery systems, are presented. The final Technical Session concludes with a discussion of the military, scientific, and general objectives for decelerators intended for future use.

A test was conducted in the Propulsion Wind Tunnel (16T) of the Propulsion Wind Tunnel Facility to determine the flow field in the wake of an ejection seat escape system at transonic flight conditions, and to determine the performance characteristics of a stabilization parachute attached to the back of the ejection seat model. The results were obtained for both simulated rocket-off and rocket-on conditions through a model angle-of-attack range from 0 to 30 deg. High pressure air was used to simulate the escape rocket jet plume at a sea-level altitude. The results show that the ejection seat model was statically unstable, but became longitudinally stable with the parachute for the test range investigated. (Author).