HYPERVELOCITY TESTING OF ADVANCED SHIELDING CONCEPTS FOR SPACECRAFT AGAINST IMPACTS TO 10-KM S/

Experiments have been performed on NASA state-of-the-art hypervelocity impact shields using the Sandia Hypervelocity Launcher (HVL) to obtai n test velocities greater than those achievable using conventional two stage light-gas gun technology. The objective of the tests was to pro vide the first experimental data on the advanced shielding concepts fo r evaluation of the analytical equations (shield performance predictor s) at velocities previously unattainable in the laboratory, and for co mparison to single Whipple Bumper Shields (WBS) under similar loading conditions. The results indicate that significantly more mass is requi red on the back sheet of the WBS to stop an approximately flat-plate p article impacting at 7 km/sec and at 10 km/sec than the analytical equ ations (derived from spherical particle impact data) predicted. The Mu lti-Shock Shield (MSS) consists of four ceramic fabric bumpers, and is lighter in terms of areal density by up to 33%, but is as effective a s the heavier WBS under similar impact conditions at about 10 km/s. Th e Mesh Double Bumper shield (MDB) consists of an aluminum wire mesh bu mper, followed by a sheet of solid aluminum and a layer of Kevlar(R) f abric. It provides a weight savings in terms of areal density of up to 35% compared to the WBS for impacts of around 10 km/s.