A document discusses a study that presents the first documented extraction loads, both nominal and worstcase, and presents the first comprehensive evaluation of extraction techniques, methodologies, and tool requirements relating to extracting printed wiring assemblies (PWAs) with Card-Loks during EVA (extra vehicular activity). This task was performed for the first time during HST (Hubble Space Telescope) Servicing Mission 4.
With impending missions to Mars and to the Moon relying on an astronaut’s abilities to perform repair and servicing tasks during EVAs, this study provides some insight into what challenges may be encountered during a repair/ replacement of a PWA with Card-Loks. Extraction techniques presented in this study could be applicable to other PWA geometries with similar locking devices. Ground-based extractions also benefit from the techniques and extraction tool requirements presented in the study. The findings highlight techniques that work reliably, efficiently, and provide design requirements for tools necessary for extracting PWAs with Card-Loks on ground.
This work was done by Hans Raven of ATK and Kevin Eisenhower of Alliant Techsystems for Goddard Space Flight Center. GSC-16160-1