Presenter Information

Alex Kirkman, Utah State University

Class

Article

College

College of Science

Presentation Type

Poster Presentation

Abstract

Contamination due to outgassing of materials can cause the degradation of critical hardware of a spacecraft. Using outgassing rates, kinetic expressions can be developed and used in models to predict the evolution of molecules and migration of contaminants for specific materials. These models could be used in the selection process of materials to help mitigate the amount of contamination of mission critical hardware for the expected life of the spacecraft. By using the ASTM E1559 test standard this can be achieved. This standard uses the quartz crystal microbalance (QCM) collection approach. A temperature-controlled effusion cell, containing the sample material, impinges outgassing flux onto three QCMs. One QCM is held at LN2 level temperature to measure the total mass loss (TML) as a function of time. The other two QCMs are controlled to selected temperature values to measure the volatile condensable material (VCM) as a function of time. Using mostly existing vacuum hardware, a design for the ASTM E1559 and stand were created using solid edge. All pieces were spec'd to create a stand for the test chamber itself and a data rack for all the supporting hardware. This includes the design and wiring of an electrical control box and assembling all of the hardware.

Start Date

4-9-2020 12:00 PM

End Date

4-9-2020 1:00 PM

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Apr 9th, 12:00 PM Apr 9th, 1:00 PM

Materials Outgassing and Kinetics

Contamination due to outgassing of materials can cause the degradation of critical hardware of a spacecraft. Using outgassing rates, kinetic expressions can be developed and used in models to predict the evolution of molecules and migration of contaminants for specific materials. These models could be used in the selection process of materials to help mitigate the amount of contamination of mission critical hardware for the expected life of the spacecraft. By using the ASTM E1559 test standard this can be achieved. This standard uses the quartz crystal microbalance (QCM) collection approach. A temperature-controlled effusion cell, containing the sample material, impinges outgassing flux onto three QCMs. One QCM is held at LN2 level temperature to measure the total mass loss (TML) as a function of time. The other two QCMs are controlled to selected temperature values to measure the volatile condensable material (VCM) as a function of time. Using mostly existing vacuum hardware, a design for the ASTM E1559 and stand were created using solid edge. All pieces were spec'd to create a stand for the test chamber itself and a data rack for all the supporting hardware. This includes the design and wiring of an electrical control box and assembling all of the hardware.