Development of Novel Helmet Support Assembly for NASA Orion Crew Survival Suit

Orion Spacecraft water landing environments have necessitated the design and testing of a novel helmet support assembly as part of the NASA Orion Crew Survival Suit. Previous NASA development tests showed that having an un-restrained or over-restrained helmet resulted in unsafe helmet positions with potentially unsafe metrics from industry established head and neck injury criteria. The new helmet support assembly maintains the position of the helmet with respect to the upper torso during landing, while also reducing or eliminating load transfer from the helmet to the head. Additional requirements met by the design include coordinating with the restraint belt positioning under the neck ring, allowing for crew ingress/egress operations, maintaining downward field-of-view, not limiting the range of motion of the arms, shoulders, and neck in normal operations, and accommodating fit for varying crew sizes and gender. The HIA (Horizontal Impulse Accelerator) at Wright Patterson Air Force Base (WPAFB) simulated the effects of landing on a representative Orion seat using a suited ATD (Anthropometric Test Device) with prototype helmet support assembly. A total of 20 sled tests, including 16 water landing impact cases, and 4 abort cases, provided crew injury prediction data for landing cases deemed worst case for the crew by an Occupant Protection Working Group. For all seat orientations, suit configurations, and ATD sizes tested, the new helmet support assembly performance met quantitative HSIR deconditioned crew injury metric requirements with additional margin. An additional qualitative review of high speed video verified that the ATD motion and suit interaction was realistic and as expected. Overall this first set of development test data focused on the new helmet support assembly showed low injury risk for worst case water landings and abort scenarios, as well as provided confidence in moving towards design certification.