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ISS and Space Environment Interactions in Event of Plasma Contactor FailureThe International Space Station (ISS), illustrated in Figure 1, will be the largest, highest power spacecraft placed in orbit. Because of this the design of the electrical power system diverged markedly from previous systems. The solar arrays will operate at 160 V and the power distribution voltage will be 120 V. The structure is grounded to the negative side of the solar arrays so under the right circumstances it is possible to drive the ISS potential very negative. A plasma contactor has been added to the ISS to provide control of the ISS structure potential relative to the ambient plasma. The ISS requirement is that the ISS structure not be greater than 40 V positive or negative of local plasma. What are the ramifications of operating large structures with such high voltage power systems? The application of a plasma contactor on ISS controls the potential between the structure and the local plasma, preventing degrading effects. It is conceivable that there can be situations where the plasma contactor might be non-functional. This might be due to lack of power, the need to turn it off during some of the build-up sequences, the loss of functionality for both plasma contactors before a replacement can be installed, and similar circumstances. A study was undertaken to understand how important it is to have the contactor functioning and how long it might be off before unacceptable degradation to ISS could occur.
Document ID
20010020205
Document Type
Conference Paper
Authors
Carruth, M. R., Jr. (NASA Marshall Space Flight Center Huntsville, AL United States)
Munafo, Paul M.
Date Acquired
August 20, 2013
Publication Date
January 1, 2000
Subject Category
Plasma Physics
Meeting Information
Spacecraft Charging Technology(Noordwijk)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.