Thomas M. Donahue (1921-2004) at JPL during the Voyager 2 encounter with Neptune and its moon Triton August 26, 1989. Dr. Donahue, the Edward H. White II Distinguished University Professor Emeritus of Planetary Science at the University of Michigan, shaped space exploration through his scientific achievements and policy positions. His work started with the first use of sounding rockets following the Second World War and his influence continued to the space probes currently exploring the so