David A. Vallado is a senior research astrodynamicist with CSSI. Previously, he was a principal engineer with Raytheon Intelligence and Information Systems in Denver, CO, where he worked to integrate new technologies into ground software control systems. He is also the author of the advanced astrodynamics textbook, Fundamentals of Astrodynamics and Applications (McGraw-Hill, 1997, 3rd ed, Microcosm, 2007, 980 pgs). Mr. Vallado has been recognized in Who's Who (since 2001) and as a 1998 Outstanding Young Man of America.