Defense Event

A System Concept Study and Experimental Evaluation of Miniaturized Electrodynamic Tethers to Enhance Picosatellite and Femtosatellite Capabilities

Iverson Bell

PhD Candidate
Friday, May 08, 2015
2:00pm - 4:00pm
1005 EECS

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About the Event

The work presented in this thesis evaluates the potential of electrodynamic tether (EDT) propulsion technology to provide picosatellites (100 g–1 kg) and femtosatellites (<100 g) with orbital maneuvering capability. The miniaturized EDT concept considered in this dissertation is a fundamentally novel paradigm because it is much shorter than a conventional EDT, with total length of about 10 meters, and it considers the use of a semi-rigid tether. A detailed trade study is presented that explores the feasibility of using EDTs for small satellite drag make-up and propulsion. The trade study includes the development of a system concept and mission scenario. The results reveal that an insulated tether only a few meters long can provide these picosatellites and femtosatellites with complete drag cancellation and the ability to change orbit. EDT thrust estimates were made for a set of particular, but representative, cases and a few simplifying assumptions to facilitate estimating tether current. In order to evaluate electron current collection, ground-based plasma experiments were conducted to capture key characteristics of the satellite-low-Earth-orbit (LEO) interaction. The laboratory data were analyzed to develop expressions for the current collection behavior of picosats and femtosats. The data indicated that the WLP-based collection model could be refined with small modification to the thrust estimates. It was also determined that the anode's current collection characteristic would be impacted by the orientation of the spacecraft relative to the magnetic field and the direction of motion depending on the shape of the anode.

Additional Information

Sponsor(s): ECE

Faculty Sponsor: Brian Gilchrist

Open to: Public