After leaving the Navy in 1982, Phillips enrolled as a graduate student at UCLA. While at UCLA he carried out research involving observations by the NASA Pioneer Venus Spacecraft. Upon completing his doctorate in 1987, he was awarded a J. Robert Oppenheimer Postdoctoral Fellowship at Los Alamos National Laboratory in New Mexico. He accepted a career position at Los Alamos in 1989. While there, Phillips performed research on the sun and the space environment. From 1993 through 1996 he was Principal Investigator for the Solar Wind Plasma Experiment aboard the Ulysses Spacecraft as it executed a unique trajectory over the poles of the sun. He has authored 150 scientific papers dealing with the plasma environments of the sun, earth, other planets, comets and spacecraft.
Phillips has logged over 4,000 flight hours and 250 carrier landings. He has been a Navy reservist since 1982, serving as an A-7 pilot, commanding officer of a merchant ship convoy unit and, most recently, as a science and technology officer for the Office of Naval Research.
Planned SLS-1 shuttle mission. Cancelled after Challenger disaster.