AAS 95-346
The Evaluation of Debris Bumper Systems Using the Counter-Fire Test Technique
R. P. Young, Jr., and M. E. Smith, Micro Craft Technology/AEDC Operations, Arnold AFB, TN
Abstract
The population of man-made orbital debris has continued to increase, creating a growing impact hazard to the world's space assets, including manned and unmanned systems. It is estimated that 85 percent of all on-orbit collisions with man-made debris occur at impact velocities between 6 and 16 km/sec. Designers tasked with the development and evaluation of orbital systems capable of withstanding such impacts have had to rely primarily on impact data obtained using two-stage light-guns at velocities below 7 km/sec. Extrapolation of impact data to the required velocity regime is typically done through the use of empirical models and hydrocodes. Hydrocode development and simulation techniques are still maturing fields and require validation by comparison to test data to instill confidence in code predictions. The Arnold Engineering Development Center (AEDC) has completed the demonstration of a unique test technique known as "Counter-fire". The Counter-Fire technique is capable of providing impact data in the velocity range from 7 to 14 km/sec for the evaluation of light-weight shielding and validation of impact codes. The counter-fire technique can provide impacts at extremely high velocities resulting from the intercept of two projectiles launched from opposing two-stage light-gas guns. Currently, five counter-fire demonstration tests have been attempted resulting in four intercepts with a rendezvous velocity of approximately 12 km/sec. Impact data have been obtained on semi-infinite and multi-plate targets. The successful demonstration of the Counter-Fire test technique has resulted in a unique set of data obtained at impact velocities that had previously been beyond the testable regime. These data are valuable for the verification/validation of hydrocodes and analytical models. This paper compares the impact data obtained using the Counter-Fire technique with predictions from various empirical models and calculations from the CTH hydrocode.