∗ † ‡ λ λ ∼ 35 * † ‡ 42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 9 - 12 July 2006, Sacramento, California AIAA 2006-4655 Copyright © 2006 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.