Modeling of Fabrics and Pressurization for Actively Tensioned Mechanical Counter Pressure Spacesuit

Date

7/10/2022

Journal Title

Journal ISSN

Volume Title

Publisher

51st International Conference on Environmental Systems

Abstract

Extravehicular Activities (EVAs) will be vital to future human spaceflight missions to the moon and Mars. Not only are EVAs the most visible part of a human planetary mission, as seen during the Apollo missions, they are also pivotal in maximizing scientific output from these missions. Design of spacesuits that impose the least impediment to natural human movement and augment astronauts� capabilities during EVA remains an area of active research. A Mechanical Counter Pressure (MCP) spacesuit promises to significantly improve mobility and minimize metabolic workload over a traditional gas pressurized suit by replacing gas pressure with contact pressure of a tensioned fabric directly against the body. Several engineering challenges remain before such a suit can be used operationally. Specifically, this paper addresses providing uniform MCP of 29.6 kPa over the body, enabling easy don and doff, and minimizing mechanical work from the astronaut during suited movements. The bidirectional actuation of two-way Shape Memory Polymers (2W-SMPs) is proposed to provide controlled MCP while allowing for easy don/doff. Analysis is carried out to estimate the most optimum polymer, in terms of highest MCP produced for a given manual force input. Two common fabric types were analyzed- a woven fabric and a jersey knit fabric. Planar nonlinear finite element analysis (FEA) models to analyze the deformation of these fabrics were developed, and these will be implemented on the body surface and integrated with SMP thermomechanical model to simulate strains and pressure distributions under suited movements. FEA simulation results will inform the fabric pattern that transmits the required MCP tensioning force while minimizing mechanical work during movements.

Description

Akshay Kothakonda, Massachusetts Institute of Technology, US
Dava Newman, Massachusetts Institute of Technology, US
ICES407: Extravehicular Activity: Emerging Space Suit Technologies
The 51st International Conference on Environmental Systems was held in Saint Paul, Minnesota, US, on 10 July 2022 through 14 July 2022.

Keywords

Spacesuit, Extravehicular Activity, Mechanical Counter Pressure, Active Materials, Shape Memory Polymers, Fabric Analysis

Citation