An Airborne Parachute Compartment Test Bed for the Orion Parachute Test Program

Abstract

The test program developing parachutes for the Orion/MPCV includes drop tests with parachutes deployed from an Orion-like parachute compartment at a wide range of dynamic pressures. Aircraft and altitude constraints precluded the use of an Orion boilerplate capsule for several test points. Therefore, a dart-shaped test vehicle with a hi-fidelity mockup of the Orion parachute compartment has been developed. The available aircraft options imposed constraints on the test vehicle development and concept of operations. Delivery of this test vehicle to the desired velocity, altitude, and orientation required for the test is a difficult problem involving multiple engineering disciplines. This paper describes the development of the test technique. The engineering challenges include extraction from an aircraft, reposition of the extraction parachute, and mid-air separation of two vehicles, neither of which has an active attitude control system. The desired separation behavior is achieved by precisely controlling the release point using on-board monitoring of the motion. The design of the test vehicle is also described. The trajectory simulations and other analyses used to develop this technique and predict the behavior of the test vehicle are reviewed in detail. The application of the technique on several successful drop tests is summarized.

Test Vehicle Forebody Wake Effects on CPAS Parachutes

“…The missile-shaped Parachute Compartment Drop Test Vehicle (PCDTV) allowed for stable high-speed deployments with representative suspension hardware and could be extracted from either a C-130 or C-17. 4 The Parachute Test Vehicle (PTV) provided an Orion "boilerplate" which was somewhat truncated in height in order to fit in a C-17. 5 The latter two vehicles are currently in use for the qualification portion of the test program.…”

A Boilerplate Capsule Test Technique for the Orion Parachute Test Program

“…Extensive Monte Carlo analysis was performed on the PCDTV tests to balance the risk of releasing too late (or not at all) with the risk of a sub-optimal release point because the back-up timer was set too early. 6 A similar analysis was undertaken for the first PTV test but it indicated that the results were highly dependent on the failure mode and that there were few suboptimal (time-based) releases that would not result in a tumbling PTV. Back-up release times that would help in one failure mode would make things worse in other failure modes.…”

“…The CPAS project developed and refined this technique over several drop tests 5 including the PCDTV tests that preceded the PTV series of tests. 6 …”

Fast Database Generation for Parachute Cluster Design Using Navier-Stokes Equations on Supercomputers

“…However, design of a parachute system for the Orion capsule still utilizes the linear aerodynamic theory available in NASTRAN while modeling the multi-body dynamics using the ADAMS module [4].…”