Advanced Material Options for the Portable Life Support System

The current mass of the Exploration External Mobility Unit (xEMU) Portable Life Support System (PLSS) has far exceeded the mass requirements; >50 pounds over allocation. In order to reduce overall dimensions and mass, titanium was chosen as the primary metal for the PLSS backplate and thermal loop; however, an unintended consequence was galvanically compatible metals (Hastelloy, Inconel, Monel) have high densities and further drove up overall mass and added complexities with coatings. While some effort has been made to address to mass overage, schedule & cost became more significant drivers to produce a prototype unit. With the advent of a lunar Artemis mission and potential for future Mars missions, mass becomes a more critical driver going forward. Therefore, alternative materials and processes must be considered to fully close the mass requirement. There are many new materials and processes that can be considered; although, considerations must be made in order to ensure galvanic compatibility, radiation concerns for sensitive electronics, vacuum compatibility, tight tolerances, fluid compatibility with oxygen & water, and thread insert options. Individual PLSS components may have different requirements and need to be considered separately for reducing overall mass. This report will touch on comparisons between advanced materials, focusing on composites, 3D printing, and plastics. It will also address the different processes that may need to be applied when using these materials in the harsh environment of space. Lastly, it will look at specific components and make recommendations for options to reduce mass of each one.