- Ph.D., 1992, Theoretical and Applied Mechanics, Cornell University
- M.S., 1988, Systems Engineering, Air Force Institute of Technology
- B.S., 1984, Aerospace Engineering (with High Honor), Auburn University
- Research Expertise
- Professional History
- Awards and Honors
- Professional Leadership
- Research Interests
Spacecraft Dynamics & Control
2011 to present, Professor and Chairman, Mechanical Engineering Department, University of New Mexico, 2006-2011, Department Head, Aerospace & Ocean Engineering, Virginia Polytechnic Institute and State University; 2003-2011, Professor; 2000-2003, Associate Professor; 1997-2000 Assistant Professor, Aerospace & Ocean Engineering, Virginia Polytechnic Institute and State University; 1992-1997, Assistant Professor, Aerospace and Systems Engineering, Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio; 1984-1987, Satellite Systems Integration Engineer, Air Force Satellite Control Facility, Onizuka Air Force Base, California; 1978-1981 Telecommunications Systems Control Specialist, Air Force Communications Command, Royal Air Force Mildenhall, UK.
- 2005: Elected Fellow of American Astronautical Society
- 2002: Invited participant, National Academy of Engineering "Frontiers of Engineering Symposium,".
- 2001: Dean's Award for Excellence in Teaching.
- 1998: Best Paper Award, AIAA Astrodynamics Specialists Conference.
- 1998: Ralph E. Powe Junior Faculty Enhancement Award, Oak Ridge Associated Universities.
- 1997: Outstanding Professor Award, Southwest Ohio Council on Higher Education.
- 1997: Ralph R. Teetor Educational Award, Society of Automotive Engineers.
- 1996: Colonel Charles A. Stone Leadership Award, Wright Memorial Chapter.
- 1996: Air Force Association, Air Force Institute of Technology
- 1994: Air Force Meritorious Service Medal.
- 1992: Tau Beta Pi Outstanding Professor Award, Air Force Institute of Technology.
- 1992: Best Paper Award, AIAA Dayton-Cincinnati Section Mini-Symposium, Dayton, Ohio
- 1991 Air Force Achievement Medal
- 1987: NASA Space Grant Fellow, Cornell University, .
- 1984: Branimir D. Djordjevic Memorial Scholarship Award, Auburn University.
- 1984:Outstanding Aerospace Engineering Student, Auburn University.
- Member, Phi Kappa Phi Honor Society
- Member, Sigma Gamma Tau Honor Society
- Alumnus Member, Tau Beta Pi Engineering Honor Society
AIAA Astrodynamics Technical Committee; Chair, 2002-2004; Advisory Board Member, Virginia Space Grant Consortium, 2000-present, Chair 2006-present; AAS General Co-chair, AAS/AIAA Space Flight Mechanics Conference, Clearwater, FL, Jan. 2000; American Institute of Aeronautics and Astronautics, Associate Fellow; American Astronautical Society, Fellow; Associate Editor, AIAA Journal of Guidance, Control, and Dynamics, 1995-2000, AIAA Astrodynamics Technical Committee; Chair, Education Subcommittee, 1994-2001; Member, AAS Space Flight Mechanics Technical Committee, 1997-2005; Associate Director, Ohio Space Grant Consortium, 1994-1997; AIAA General Co-chair, AIAA/AAS Astrodynamics Conference, Boston, MA, Aug 1998; Technical Area Chair, Space Technologies and Applications, National Aerospace and Electronics Conference, Dayton, OH, Jul 1997; Technical reviewer for Acta Astronautica, Celestial Mechanics and Dynamical Astronomy, J. of Guidance, Control and Dynamics, J. of Spacecraft and Rockets, J. of Applied Mechanics, Nonlinearity, J. of the Astronautical Sciences, J. of Dynamic Systems, Measurement, and Control
Spacecraft Dynamics and Control
Research focuses on spacecraft dynamics and control, particularly where attitude control is effected by applying torques to internal rotors such as reaction wheels, momentum wheels, and control moment gyros, and where energy dissipation is achieved using damping mechanisms. The analysis of these problems involves nonlinear differential equations which in many cases may be expressed as a noncanonical Hamiltonian system, or as a perturbation of such a system. Using standard applied mathematics techniques, including special functions, averaging, multiple scales, WKB, continuation, and Lyapunov-Schmidt reduction, I have obtained new insights into several of these spacecraft problems. These techniques are also applicable to other problems involving rotating mechanical systems of coupled rigid and flexible bodies, such as human body kinetics, rotor dynamics, machine vibration suppression, and flywheel energy storage devices. This research has been supported by the Air Force Office of Scientific Research, the Air Force Research Laboratory, the Space Warfare Center, the Space and Missile Center, NASA Goddard Space Flight Center, and the National Science Foundation
Two space dynamics-related laboratories exist at Virginia Tech. The Space Systems Simulation Laboratory includes two spherical air bearings with approximately 150kg payload each, and allows experimental verification of algorithms and control laws involved in the large-angle, three-dimensional motion of rigid and flexible bodies using internal and external torques, along with distributed control and inter-satellite communications. The Satellite Tracking Laboratory is an education-focused lab, and includes computers and an amateur satellite ground station. Students in space-related courses can perform a variety of experiments involving actual satellites, aimed at strengthening their understanding of space dynamics, state estimation, motion prediction, and space physics, and the effectsthese principles have on the design and operation of spacecraft.
Spacecraft Design and Space Mission Design
Especially interested in projects that give students hands-on experience in designing, building, and testing space payloads, including systems for sounding rockets, high-altitude balloons, and orbital missions.
- (505) 277-1325
University of New Mexico