EVA safety design guidelines

An Extravehicular Mobility Unit is a closed and isolated environment that protects the astronaut from exposure to space environment. Eighty-four percent of the possible hardware failures occurring during Extravehicular Activity (EVA) would result in an abort of the EVA. Fifty-two percent of these failure modes would result in a loss of a critical life support function and directly compromise crew safety. Crew safety is not, however, limited to controlling hardware failures. Safety can be compromised by improper in-flight servicing or induced by interfacing equipment during EVA related activity. This paper addresses these potential hazard sources and approaches used to enhance equipment reliability and astronaut safety.