Dynamics and Control
- 2010 – present, Assistant Professor, Aerospace and Ocean Engineering, Virginia Tech.
- 2007 – 2008, Researcher and Lecturer, Space Systems Engineering, University of Glasgow, Scotland.
- 2005 – 2007, Senior Engineer and Group Lead, StarVision Technologies
Reviewer for the following journals:
- IEEE Aerospace
- Acta Astronautica
- Engineering Optimization
- Celestial Mechanics and Dynamical Astronomy
- Journal of Spacecraft and Rockets
Spacecraft Design and Space Mission Design
- The SSSL is now hosting a variety of projects that give students hands-on experience in designing, building, and testing space payloads. These missions include: the Virginia Tech CanSat team(s), sounding rocket payloads, high-altitude balloon payloads, orbital missions, the HokieSat team (student designed and built satellite), and the Lunabotics (Lunar mining) competition.
Spacecraft Dynamics and Control
- This research focuses on spacecraft dynamics and control, particularly on orbit and attitude identification, orbit maneuvers, and attitude control. Orbit and attitude identification are based on observations (of many possible types) and use new, specialized algorithms for the identification. With orbit maneuvers, we seek to expand the envelope of what has been studied and open new trajectories through Hamiltonian dynamics, Lagrange points, weak stabilities, and other methods. Attitude control is based on the implementation of control laws to achieve a desired pointing given a set of actuators or torque mechanisms. A new area of interest is precision planetary landing through the use of inflatable aero-shells.
- As the space around earth becomes more populated, understanding the impact of orbital debris is a significant portion of future space missions. This research involves all aspects of understanding and mitigating the effects of orbital debris, from observation, correlation, tracking, avoidance maneuvers, and debris removal. A large portion of this effort is simulation of a large number of inhomogeneous bodies on orbit with uncertainties.
Optimization in Astrodynamics
- Numerical optimization is a major component of solving complex problems in astrodynamics. The research involves various aspects of numerical optimization, including algorithm development and test. Applications include Space Situational Awareness (SSA), orbit maneuvers, attitude maneuvers, interplanetary trajectories, and constellation design.
- The Space Systems Simulation Laboratory (SSSL) includes two spherical air bearing spacecraft simulators, each allowing approximately a 150 kg payload. The simulators allow experimental verification of large-angle, three-dimensional motion and control of rigid and flexible bodies. The two simulators allow a coupling of orbit and attitude dynamics, or attitude dynamics only. The simulators can work simultaneously for orbit rendezvous scenarios.