This paper examines the use of spacesuit simulators for development and initial testing of technologies and architectures for advanced EVA systems, particularly pressure garments. By performing initial evaluation and operational testing in analogue environments, suit system enhancements can be assessed for continued development into pressurized suit systems, and possible extension to flight. The paper examines in detail the development and testing of the MX-D suit simulator system at the University of Maryland for this purpose. This system is designed to be a comparatively high-fidelity suit simulation, using various elements to replicate the bulk and restriction of current pressurized suits, while keeping the weight on the test subject representative of suit loads for the moon or Mars. The MX-D system is highly modular, facilitating easy change-out of prototype components to obtain direct comparisons of relative performance under identical circumstances, such as various shoulder or knee architectures. The MX-D has incorporated some elements of potential future suit architectures, such as chest-mounted battery packs allowing self-swapping and hot-swapping during an EVA, and the ability to use umbilical-supplied life support for a NIAC study. By adopting a separate "bubble" helmet rather than a torso-mounted hemispherical or ellipsoidal faceplate, helmets can be customized for specific experimental augmentations, such as an in-helmet data projection system, without impacting use of the rest of the suit. The system incorporates a thermoelectric cooling system for subject comfort with minimal impact on overall weight. Many suit elements are produced using additive manufacturing to allow rapid prototyping and testing of alternative designs, as well as simplifying development of variants such as suits optimized for underwater testing. The paper concludes with lessons learned to date from the MX-D development process, and discusses useful features for future suit simulators.
Akin et al. (Sun,) studied this question.