Development and Testing of a Next-Generation Spacesuit Simulator for Analog Field Tests

Building on more than two years of collective field test time with spacesuit simulators, the University of Maryland has begun the development and testing of a fourth generation suit simulator: the MX-D. Like the preceding designs, the MX-D was developed to replicate the bulk, restrictions, and workload impact of pressurized suits to the extent practical in the analog environment. One of the major advances in the previous design was the incorporation of a backpack frame internal to the suit, which allowed load transfer from the shoulders to the hips, resulting in greater wearer comfort. All previous suit versions incorporated a commercial liquid cooling vest and an ice water cooling reservoir in the backpack. The suit backpack mounts a LiFePO4 battery to power both the liquid cooling pump and separate ventilation fans for the helmet and the limbs of the wearer. The next-generation MX-D has been designed in response to user comments in extended testing at HI-SEAS. For safety, the design incorporates “bail-out” options, allowing the wearer to egress the suit unaided in less than thirty seconds. It is also designed for simple replenishment of both batteries and cooling reservoirs in the field. Dual ice water containers and batteries are incorporated to provide continuous operation during changeouts, and were made highly modular to facilitate suited changeout by other personnel in the field. External service ports also allow using external cooling and power during an EVA, such as during traverses on an appropriately-equipped rover. By providing simple in-situ resupply, the MX-D suits do not place any constraints on the duration of EVA simulations. A redesigned helmet and ventilation system improves visibility and safety, while increasing ventilation rates and user comfort. The MX-D garment and helmet have also been designed to allow their use in underwater simulations.