Meeting the challenges of hypervelocity impact testing at 10 km/s

Abstract

The ability to evaluate the response of spacecraft hardware to the impacts of orbital debris at velocities of interest, e.g., 9 to 11 km/s, has been an elusive goal of the hypervelocity impact community. This velocity range is greater than the capability of two-stage, light-gas guns traditionally used to test spacecraft shields, structures, and thermal protection systems. To meet the need for test capabilities at these higher velocities, the University of Dayton Research Institute (UDRI) developed a three-stage, light-gas gun and used it to launch Nylon, aluminum, aluminum oxide, and stainless steel spheres to velocities up to 10 km/s. The development of the three-stage, light-gas gun, a reliable functioning sabot, and a method of discarding the sabot after its use posed significant design and operational challenges. This paper describes: (1) the three-stage, light-gas gun; (2) a unique, one-piece sabot design required to withstand the extreme accelerations and loads imposed on the spheres and sabots during their launch, and (3) a novel method of discarding the sabot after its use. It concludes with the presentation of the results of two tests performed on spacecraft hardware at impact velocities of 9.23 and 9.90 km/s.