Classical Element Feedback Control for Spacecraft Orbital Maneuvers

The recent addition of autonomous formation flying spacecraft to the world's satellite fleet provides new motivation to study feedback control techniques. In this thesis, we develop nonlin-ear orbit control laws for use in spacecraft orbital maneuvers, and spacecraft formation flying. We apply these new control laws to a number of sample maneuvers, including formation establishment and formation keeping maneuvers for NASA-Goddard's Leonardo-BRDF formation, and coupled orbit, and attitude maneuvers for HokieSat, a spacecraft designed, and built by students at Virginia Tech to fly in the Ionospheric Observation Nanosatellite Formation (ION-F). To provide target orbit states for feedback control, we develop and apply an algorithm to calculate a formation master orbit representing the geometric center of the formation. We also define a new technique for choosing orbital element feedback gains which appropriately scales the gains for orbit maintenance, and provides an excellent starting point for gain optimization. The orbital element feedback control law, augmented by mean motion control, and applied with appropriate gains, forces asymptotic convergence to a spacecraft target orbit, for a large variety of spacecraft maneuvers. Acknowledgments As I finish this chapter of my life, I would like to thank everyone who has made seven years of higher education possible, fruitful, and to say the least, enjoyable. In particular, I would like to thank Dr. Chris Hall, who has been my advisor throughout the majority of this adventure, and who somehow convinced me to stay at Virginia Tech to pursue my master's degree. I could not have asked for a better experience, or a better advisor. I would also like to thank Dr. Fred Lutze, and Dr. Craig Woolsey for their contributions to this work, both as members of my committee, and as excellent instructors of dynamics and control. I would like to thank my parents, whose love and support have been endless, and the rest of my family and friends, who have helped make the last few years great.