Operating Plasma Contactor Experiments Onboard the ISS – Lessons Learned from PLEGPay
T. Hoppenbrouwers ; Z. Pronk ; G. Noci ; - ASI Sponsor
Apr - 2010

Event Title : SpaceOps 2010 Conference. 5 - 30 April 2010, Huntsville, Alabama
Published in: American Institute of Aeronautics and Astronautics, Inc.
Publisher: AIAA
type: Conference Proceedings

The Plasma Contactor Electrical Grounding Payload (PLEGPay), part of the European Technology Exposure Facility (EuTEF) mounted outside Columbus aboard the International Space Station (ISS), has been operated from February 2008 until September 2009 from the Erasmus USOC, a Belgian-Dutch User Support and Operations Centre located at ESA/ESTEC. While performing the PLEGPay plasma contactor experiments, the floating potential of the station was changed significantly, although not exceeding nominal limits. However, it alerted the entire ISS community and the payload was categorized as an ‘undefined and therefore catastrophic hazard’ for the ISS. Since PLEGPay was already performing on-orbit operations, hardware design changes to control this newly classified hazard were not feasible anymore. The continuation of PLEGPay and EuTEF operations was challenging for the operational and engineering support teams and has proven to be a balancing act between scientific and technological wishes, ISS environmental control and safety related aspects (EVAs, Visiting Vehicle activities, etc.). This paper focuses on the operational and organizational aspects of plasma contactor experiments onboard the ISS and describes the event and the steps leading up tothe eventual forced shutdown of PLEGPay and EuTEF and how the operations were gradually resumed afterwards. Lessons learned were derived and are described in order to avoid similar conflicts related to operations and safety as experienced during the PLEGPay mission, and to increase the scientific and technological return for a future plasma contactor experiment on the ISS.

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