Effect of Multi-Layer Insulation on Top of Spacecraft Meteoroids/Debris Shields: Prediction of the Automated Transfer Vehicle Pressure Module Ballistic Limit

摘要

Numerical simulations of normal incidence impact tests on the Automated Transfer Vehicle (ATV) pressure module meteoroids/debris shield were performed with the AUTODYN-2D hydrocode, in order to investigate the ballistic performance degradation of the initial Whipple shield configuration with Multi-Layer Insulation (MLI) attached on top of the bumper. The results showed that the presence of MLI reduces the intensity of the release wave in the front part of the projectile, leaving it in a poorly fragmented state after the bumper perforation and thus producing a larger damage on the back wall. A consistent enhancement of the ballistic limit was obtained by introducing a stuffing layer of Nextel and Kevlar between the bumper and the back wall. Simulations represented well the experimental back wall damage on the Whipple shield targets with and without MLI, and on the final stuffed configuration. The numerical, model was used to extrapolate the ballistic limit of the stuffed shield for normal impacts in the velocity range above the experimental results, and the obtained ballistic curve was compared with the semi-empirical equation actually used to determine the ATV Probability of No Perforation (PNP). A PNP calculation was performed with the ESABASE/DEBRIS code using both the numerical and semi-empirical ballistic curves, assuming a randomly tumbling plate along the International Space Station orbit as a simple geometry test case.