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dc.contributor.advisorDutta, Atri
dc.contributor.authorSreesawet, Suwat
dc.descriptionThesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering
dc.description.abstractElectric propulsion is gaining popularity among satellite operators due to its fuel e ciency. However, electric propulsion has the limitation of producing a small magnitude of thrust, meaning that the transfer time to geostationary orbit is of the order of several months. The long transfer time adds more complexity to the mission design process due to the long exposure to hazardous radiation belts. Obviously, thrusters require electric power that is generated from sunlight by satellite solar panels. Therefore, the earth's shadow signi cantly impacts the orbit-raising maneuver. This study proposes a novel, robust, and fast numerical methodology for generating low-thrust trajectories to the geosynchronous orbit. This methodology utilizes a new set of state variables that has a physical interpretation and exhibits slow variation under a small magnitude of thrust. The absence of mathematical singularities in the equatorial plane adds to the bene ts. The new set of state variables, along with a closed-loop guidance scheme and direct optimization methodology, is used to optimize the satellite trajectory. An unconstrained optimization scheme is able to robustly and rapidly generate low-thrust orbit-raising trajectories for a variety of mission scenarios, various initial orbits, application of electric battery to allow thrusting during eclipses, and orbital perturbations due to the earth's oblateness or a third body. The proposed methodology can be seamlessly integrated into receding horizon control scheme, which recomputes the minimum time trajectory at regular intervals referred to as planning horizon. The attitude of spacecraft must also be maintained in a desired direction which can be time-varying. Regular satellites perform orbit-raising using stowed solar array. In contrast, all-electric satellites perform orbit-raising using deployed solar arrays. Therefore, simple inverse controllers for attitude control with a neural network-based observer has been studied and evaluated. We demonstrate that the performance of the inverse controller is drastically improved with the proposed observer.
dc.format.extentxiv, 150 pages
dc.publisherWichita State University
dc.rightsCopyright 2018 by Suwat Sreesawet All Rights Reserved
dc.subject.lcshElectronic dissertations
dc.titleOptimal orbit-raising and attitude control of all-electric satellites

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  • AE Theses and Dissertations
    Electronic copies of theses and dissertations defended in the Department of Aerospace Engineering
  • CE Theses and Dissertations
    Doctoral and Master's theses authored by the College of Engineering graduate students
  • Dissertations
    This collection includes Ph.D. dissertations completed at the Wichita State University Graduate School (Fall 2005 --)

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