Ultra-high-molecular-weight polyethylene as a hypervelocity impact shielding material for space structures

Abstract

Space debris impacts at hypervelocity of several tens of km/s threaten the survival of space structures. In the case of International Space Station, the concept of Whipple shield is applied to protect the astronauts and the electronic devices from impact of space debris. In this study, a Whipple shield design comprising of ultra-high-molecular-weight polyethylene were proposed to improve the space debris impact shielding efficiency over conventional Whipple shields. Ballistic performance was evaluated by a two-stage lightweight gas gun capable of accelerating 5.56 mm diameter aluminum projectiles to 4 km/s. High-temperature impact tests and outgassing tests were performed for space environment application. Through the test, ultra-high-molecular-weight polyethylene was better ballistic performance and outgassing properties than Kevlar used in conventional Whipple shield. Ultra-high-molecular-weight polyethylene can be an effective way to provide cosmic radiation shielding and ballistic capability for future spacecraft designs.