Flight Tests of an Unmanned Powered Parachute: A Validation Tool for GN&C Algorithms

Advanced Mission Design Branch, NASA Johnson Space Center
1 September 2000 – 31 December 2001
Co-P.I.s Donald T. Ward, Thomas C. Pollock, and David W. Lund
Total award $219,534

Paratows  buckeyes
The NASA X-38 is the prototype of a Crew Return Vehicle (CRV) which will be used as an emergency escape system or lifeboat from the International Space Station. The X-38 and CRV are some of the first re-entry vehicles to use a parafoil for maneuvering during the terminal phase of its operational trajectory. The CRV will operate with a high degree of autonomy, and its guidance algorithms must be able to avoid obstacles in the landing area, and permit touch down with a rate of descent that will not harm the vehicle occupants, who could be injured or otherwise incapacitated.

To exercise the guidance algorithms and serve as a testbed for the X-38, NASA purchased two Buckeye “powered parachutes”. One vehicle was configured and instrumented to fly autonomously. To assist with the modeling of this vehicle and validation of the guidance algorithms and instrumentation package, tow tests of the X-38 parafoil system (above left) and flight tests of the Buckeye vehicle (above right) will be conducted at the Flight Test Facilityof the Texas A&M Flight Mechanics Laboratory.

Specific tasks and research objectives:

  • Assess the ability of various guidance algorithms to be flown on V201 to maintain heading control.
  • Measure the targeting capability of algorithms for V201 use.
  • Validate wind alignment and estimation performance attained by the guidance algorithms.
  • Quantify navigational errors (including actual deviations from the desired trajectory, biases, noise, etc.) acheieved during the simulated terminal phase maneuvering.
  • Compare data from Buckeye flights to simulator predictions of performance and extrapolate the findings to the X-38 vehicle in its terminal maneuvering.
  • Provide a hvehicle for emulating pallet drops (modeling the larger parachute planned for V201) that could use the terminal guidance algorithms.
  • Develop and valdiate the use of the autonomous Buckeye vehicle as a hazard avoidance testbed.

Working with me on this program are Graduate Research Assistants:

  • Gi-Bong Hur
  • Dallas Hopper
  • Edward R. Caicedo