BEGIN:VCALENDAR BEGIN:VEVENT SUMMARY:AME Department Seminar DESCRIPTION:Speaker: B. Villac , Professor, University of California at Irvine Talk Title: Humans Beyond Low Earth Orbits: Challenges and Opportunities in Astrodynamics Abstract: The NASA plan for sending humans beyond low-Earth orbits in a sustainable manner poses many challenges (at all levels: technical, political,...), as well as a plethora of opportunities. This talk explores a few of the technical challenges and opportunities in the realm of spaceflight dynamics.\n \n Firstly, sustained exploration implies a need for space-based infrastructure, notably for navigation and communication systems. This leads us to a discussion on constellation optimization in multi-body environments, and the associated variational problems. We show that the use of dynamical system theory and the analysis of periodic orbit families allows us to reduce this problem to a one-dimensional optimization over a graph. These results are applied to the concept of autonomous navigation constellation. The notion of family --i.e., continuous set of orbit-- is then extended to transfer problems, demonstrating some limitations of classic design methodologies and possible techniques to go around these.\n \n Secondly, humans in space also implies safety issues. This is notably amplified with the current vision of sending humans to asteroids, where the dynamics present short time scales and is generally poorly characterized before encounter. Here the questions addressed are the techniques to ensure mission recovery --or at least avoiding critical events such as impacts or uncontrolled escape when orbiting a small body-- in the face of potential engine failure. The analysis of the resulting optimal control problems and orbital stability issues leads to new transfer and mission concepts and the challenging problem of orbital motion characterization under large parameter uncertainties.\n \n Finally, a few astronauts in space means a large team of qualified engineers on the ground, planning, designing, preparing, operating, supporting the missions ans the astronauts. All this, starts with education and the formation of good engineers. The last part of the talk will briefly discuss the cubesat project pursued at UCI in order to answer this need.\n Biography: Prof. Villac is currently assistant professor at the University of California, Irvine (UCI). Prior to joining UCI in 2006, Prof. Villac worked at the Jet Propulsion Laboratory and the California Institute of Technology, developing novel low-thrust trajectory analysis and design methods for the Jupiter Icy Moon Orbiter mission. He received his Ph.D in aerospace engineering in 2003 from the University of Michigan, Ann Arbor. His research is focused on astrodynamics, exploring the applications of modern dynamical system theory to the analysis and development of new space mission concepts. He is also advising the UCISAT project which is currently preparing to launch its first cubesat. Host: Prof. F. Udwadia More Info: http://ame-www.usc.edu/seminars/2-2-11-villac.shtml DTSTART:20110202T153000 LOCATION:SSL 150 URL;VALUE=URI:http://ame-www.usc.edu/seminars/2-2-11-villac.shtml DTEND:20110202T163000 END:VEVENT END:VCALENDAR