July 7, 2019
The Extravehicular Mobility Unit (EMU) EVA suit on the International Space Station (ISS), weighing more than 120 lbs. in 1-g, was first designed for the Space Shuttle program in the 1970’s, and specifically designed to operate only in a microgravity vacuum environment, not on Lunar or other partial gravity surfaces, such as Mars. The EMU also inhibits bending in the knees and waist which are essential in planetary exploration activities. To support future space exploration goals, the AHSL is pursuing a suit design strategy similar to the Apollo program, focused on the A7LB which many crew members considered the most successful EVA suit. Each Apollo crew member had 3 customized suits: 2 flight and 1 training. These suits were “soft” as opposed to the EMU Hard Upper Torso (HUT) and less massive, weighing less than 80 lbs. When the A7LB was first developed, many of the modern scanning and modelling tools were not yet developed. The AHSL is currently evaluating the use of several whole-body scanning systems to create digital human models (DHM) and integrate them into digital suits (CAD) with corresponding material properties. In this pilot study, a human subject was scanned using a Vitronics® Vitus laser scanner to create a 3D avatar model. With the capabilities of CAD/Vidya, a clothing design and simulation software package, garment patterns were designed in a configuration that replicates the structure of the A7LB, including the material properties of each layer. CAD/Vidya software can simulate up to 20 layers with corresponding material properties. The A7LB suit being modelled is the James Irwin suit; 2D drawings were acquired from the Smithsonian and converted to 3D CAD models. The virtual suit was stitched together and integrated with the human avatar in a simulated motion environment (without a pressure differential). Simulations generate color mappings of objective metrics such as distance from the body surface, and garment weft stress, which could be used to predict performance. A goal of this research is to ultimately develop the capability to rapidly produce customized prototype suits that achieve optimal performance for any size crew member, reducing both cost and production times.
Hall, Dillon. Modelling of Extravehicular Activity (EVA) Suits using Vitronics® Vitus Laser Scanning Coupled with CAD/Vidya Software for Fabric Behaviors. Poster presented at: 49th International Conference for Environmental Systems (ICES) held in Boston, Massachusetts.; 2019 Jul 7 – 11;