Bachelor of science from Lehigh University, 1966; master of science in physics from Georgetown University, 1974; Ph.D. in physics from Georgetown University, 1975; prior to his selection he worked as an astrophysicist at the Naval Research Laboratory, where he worked again after his mission; currently he serves as manager for ISS at NASA JSC.
He was Assistant Payload Specialist (officially: Ground Alternate Payload Specialist) for STS-35 Astro-1, 1990 and STS-67 Astro-2, 1995. In that position he had no flight status. In addition to supporting the crew with the science experiments he served as Crew Communicator in the Payload Operations Center at NASA MSFC.