Paper Number
PO122
Session
Poster Session
Title
Dynamic mechanical analysis of fibers for the selection of EVA spacesuit outer-layer TMG materials
Presentation Date and Time
October 12, 2022 (Wednesday) 6:30
Track / Room
Poster Session / Riverwalk A
Authors
- Markiewicz, Natalia (University of Delaware, Department of Chemical and Biomolecular Engineering)
- Wagner, Norman J. (University of Delaware, Chemical and Biomolecular Engineering)
Author and Affiliation Lines
Natalia Markiewicz and Norman J. Wagner
Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716
Speaker / Presenter
Markiewicz, Natalia
Keywords
experimental methods; composite rheology
Text of Abstract
Within the decade, NASA will again land astronauts on the moon as a part of the Artemis mission. This and many more missions to the moon will be conducted as a long-term lunar habitat is built and sustained to prepare for travel to Mars. Work on the moon will be conducted on the southern pole due to the discovery of water in this area, where temperatures can reach a low of roughly 40 K. Astronaut extravehicular activity (EVA) will be a necessary component of work planned for these trips. Therefore, the EVA lunar spacesuit, thermal micrometeoroid garment (TMG), must have an outermost ripstop layer that withstands the extreme temperatures as well as the temperature cycles that will occur throughout the missions. To understand the limitations of spacesuit materials, their mechanical properties at low temperatures are of critical importance. We perform Dynamic Mechanical Analysis (DMA) using an instrument which can realistically reach approximately 138 K using liquid nitrogen as a cooling source. Fibers of Kevlar, Nomex, and Gore-Tex, which comprise the fabric in the current TMG’s outer woven layer, Orthofabric™, are tested as a starting point. Conducting various types of runs via DMA allows for understanding each of the material’s mechanical behavior until fail time and will allow for extrapolation to lower limits until a technique for conducting DMA below 138 K is achieved. Further, Orthofabric™ is tested under a torsional deformation to LN2 temperatures to assess the fabric system behavior at low temperature. Such testing should facilitate the prediction of material lifetime. Data collected thus far shows that as temperature is decreased, the storage modulus increases, which is expected and comparable to literature on cryogenic treatment of polymers. However, the trends change as strain is changed. Temperature sweep cycles lend insight into the durability of these fibers after longer periods of wear. The overall goal is to aid in the construction of future Lunar EVA spacesuits by using rheological techniques.