Guided Parafoil High Altitude Research (GPHAR) Flight at 57,122 ft

Abstract

The purpose of this paper is to summarize the results and document lessons learned following the successful test of a tropopause inflation and flight of a guided parafoil system. The flight was conducted under the NASA Flight Opportunities Program (FOP) on 6 June 2014 from 57,122 ft. MSL using a helium balloon. The total system weight was 224 lb. which flew using a 230 ft 2 parafoil.The primary objectives of the GPHAR program are to both investigate the flight envelope and mature the technology related to the deployment and flight of parafoils at altitudes above 25,000 ft. MSL. Achieving these objectives will enable parafoil systems to be a new viable method for space vehicle recovery.The program had 3 primary technical challenges: 1) successful deployment and inflation of the parafoil system, 2) achieving a stable steady state flight condition, and 3) demonstrating stable and predictable response to AGU control input. Given the lack of precedence of parafoil flight in low density atmosphere, achievement of any one of the three challenges would have been determined a success.During the test, all three challenges were completed successfully. The system successfully released, inflated, and was then controlled with scripted flight followed by autonomous flight. The script portion of flight was a sequence of left and right turns which repeated until transition into autonomous flight at around 12,000 ft. MSL.Data collected during the flight included GPS, inertial, and control data logged onboard the Airborne Guidance Unit (AGU), high definition video, and weather sonde atmospheric data. These data have enabled a number of findings related to high altitude parafoil flight concerning flight performance and turn responsiveness, which will be discussed.In addition to summarizing the test results, this paper will make comparisons of the deployment and inflation data of the 57,122 ft. drop to data collected from an earlier test of the GPHAR system which was conducted at 3,800 ft. MSL. This paper will also evaluate considerations for further exploration of the parafoil flight envelope and make recommendations of future development.