Space radiation and hypervelocity impact shielding for low earth orbit space structures using ultrahigh-molecular-weight polyethylene

Abstract

Space radiation is defined as particle radiation consisting of protons, heavy ions, and electrons. Space radiation has a catastrophic effect on satellite electronics and reduces its lifespan. It also greatly limits the performance of satellite electronics. It makes it impossible for astronauts to stay in space for long-term because of the potential of various diseases and cancer. Polyethylene is known to perform very well in space radiation shielding. In particular, ultra- high- molecular- weight polyethylene (UHMWPE) has very high mechanical performance. Meanwhile, there are millions of space debris in Earth's orbit now. These debris have hypervelocity impact of several tens of km/s depending on the orbit and thus threaten the survival of space structures. In the case of International Space Station, the concept of Whipple shield, a dual aluminum protection system, is applied to protect the astronaut from impact of space debris. In this study, space radiation shielding and hypervelocity impact performance of proposed space structure system with ultra- high- molecular- weight polyethylene is investigated. Cyclotron was used for proton irradiation test. Also, a two stage light gas gun was used for hypervelocity impact test. The UHMWPE showed better performance in space radiation shielding and hypervelocity impact than Kevlar.