Spacesuit Hard Upper Torso Assembly: Development of Fit Metrics and Customized Design Frameworks

Abstract

The Hard Upper Torso (HUT) of the spacesuit pressure garment is a central component of a spacesuit, enclosing the upper body and connecting with the shoulder joints, bearings, helmet, hatch, and waist-brief-hip components. The shape and positioning of the HUT and its connected components are critical for ensuring comfort, range of motion, field of view, and minimizing astronaut injury risk.

This dissertation aims to build upon previous work on spacesuit sizing and develop new spacesuit fit metrics. Motion-tracking technology has been utilized to define the reach envelope and range of motion for test subjects wearing a HUT. Subjective surveys have also been conducted to evaluate suit mobility, feature alignment, indexing, and discomfort. These tools can be adapted to investigate the effects of HUT sizing, leading to the proposal of new metrics ideal for the fit and mobility of HUT based on these technologies.

Additive manufacturing can be employed to create custom spacesuit hardware with minimal additional manufacturing steps. This technique enables efficient testing and benchmarking of a wide variety of HUT prototypes. With the development of fit and performance metrics, it becomes logical to utilize these metrics to design optimally sized HUT geometry.

The above goals were pursued through the following activities:

1. Define two separate HUT design frameworks: The first framework will result in an optimally distributed discreet HUT sizing system, while the second will establish a framework for the rapid prediction and design of customized HUTs.

2. Investigate the subjective effect of HUT customization on HUT fitment using a subjective fit survey, demonstrating the benefits of HUT customization.

3. Explore the effect of HUT customization using human in-the-loop testing, including range of motion and reach envelope analyses, highlighting the benefits of HUT customization on suited mobility.

4. Confirm the preliminary feasibility of 3D printed HUTs through stress analysis of virtual HUT prototypes using a range of pressures, shell thicknesses, and candidate materials.