Benjamin F. Villac, Ph.D.
Office: Engineering Gateway 3227
Reaching other worlds, navigating among celestial bodies! Spaceflight mechanics made space exploration possible. While the basics of space mechanics are straightforward to grasp, the optimization and global analysis of motion in multi-body systems still present challenges for the design of complex and efficient missions. Abstracting from these applications, the study of nonlinear dynamical systems is both of a practical and theoretical interest. Quest ions of interests to my research are the study of global properties of the systems such as the regions of stability, chaotic transport across phase space and the relation to optimal control. Another fundamental issue concerns the relation between complex models and their approximations. An example is given in celestial mechanics by the study of quasi-integrable systems where the limitations of the integrable approximations to the non-integrable dynamics offer deep insight in the structure of the system. In spaceflight mechanics, the family of restricted three-body problems offer another example of a class of simplified models used to analyze more complex design problems. Finally, the study of the uncertainty propagation and the computational theory associated with dynamical systems is essential for actually operating a spacecraft. While this area is certainly related to the previous issue, it brings forth different tools and insights into the study of spaceflight, nonlinear systems and control.
After completing my undergraduate education in France (Ecole Nationale de Techniques Avancees, Paris, France), I joined the University of Michigan for my graduate studies. There, I received a MSE and Ph.D degree in Aerospace Engineering in 2000 and 2003 with a thesis on spacecraft dynamics and orbital transfers around planetary satellite under the guidance of Prof. Daniel J. Scheeres. My interest in mathematics also lead me to earn a MS degree in Mathematics in 2002. After graduation, I worked as a post-doctoral scholar at the California Institute of Technology under the supervision of Dr. Martin Lo and Prof. Alan Barr and joined the Outer Planet and Mission analysis group at the Jet propulsion Laboratory in November 2004. I finally joined the Mechanical and Aerospace Engineering at the University if California, Irvine in July 2006.
|MAE146 Astronautics (Winter 2007)|
Selected Journal Articles:
M. Lara, R. Russell, B. Villac, Classification of distant stability regions at Europa, Journal of Guidance, Control and Dynamics, to appear.
D.J.Scheeres, F.-Y.Hsiao, R.S.Park, B.F.Villac, J.Maruskin, Fundamental Limits on Spacecraft Orbit Uncertainty and Distribution Propagation, Journal of the Astronautical Sciences, to appear.
B.F.Villac and D.J.Scheeres, On the concept of periapsis in the Hill problem, Celestial Mechanics and Dynamical Astronomy Vol. 90, No. 1-2, pp. 165-178, 2004.
B.F.Villac and D.J.Scheeres, A new class of optimal plane change maneuvers, Journal of Guidance, Control and Dynamics, vol. 26, No. 5, pp. 750-757, 2003.
Selected Conference Papers:
B.F.Villac, M.Lara, Stability maps, global dynamics and transfers Proceedings of the 2005 AAS/AIAA Astrodynamics Specialist Conference, Paper AAS 05-378.
B.F.Villac, D.J.Scheeres, A simple algorithm to compute Hyperbolic Invariant Manifolds near L1 and L2, Proceedings of the 2004 AAS/AIAA Spaceflight Mechanics meeting, Paper AAS 04-243.
B.F.Villac, D.J.Scheeres, One impulse vs. 3rd body driven plane changes Proceedings of the 2003 AAS/AIAA Spaceflight Mechanics meeting, Paper AAS 03-519.