Trade Study of an Interface for a Removable/Replaceable Thermal Micrometeoroid Garment 2008-01-1990

Effective thermal and micrometeoroid protection as afforded by the Thermal Micrometeoroid Garment (TMG) is critical in achieving safe and efficient missions. It is also critical that the TMG does not increase torque or decreased range of motion which can cause crewmember discomfort, fatigue, and reduced efficiency. For future exploration missions, removable and replaceable TMGs will allow the use of different pressure garment protective covers and TMG configurations for launch, re-entry, 0-G Extra Vehicular Activity (EVA), and lunar surface EVA. A study was conducted with the goal of developing high Technology Readiness Level (TRL), scalable, interface design concepts for TMG systems.

The affects of TMG segmentation on mobility and donning were assessed. Closure mechanisms were investigated and tested to determine their operability after exposure to lunar dust. A TMG configuration with the optimum number of segments and location of interfaces was selected for the Mark III spacesuit. Interface segments were designed based on the study of closure mechanisms, dust test results, and trade studies of interface concepts. Interface segments were fabricated and tested to verify meeting the goals and requirements described in the Crew, Robotics, and Vehicle Equipment (CRAVE) Delivery Order (DO), DO-CRAVE-EC5-D026. The most important criteria driving the interface design were determined to be the ability to don the TMG over a pressurized suit, the ability to actuate interfaces with a pressurized gloved hand, limiting the negative affect on mobility, and interface weight.

The principal design concept of attaching the TMG by cinching it around the pressure garment hardware has been pursued by fabrication of an arm TMG segment for the waist entry I-Suit and D-Suit spacesuits. Results of the trade study and prototype evaluation are presented in this paper.