After receiving his master's degree, Voss attended the Infantry Basic Course in 1974 where he was listed as a Distinguished Graduate. He then attended Airborne School and Ranger School, at the latter he was awarded the Honor Graduate and Leadership Award. Voss was then stationed with the 2nd Battalion, 48th Infantry Regiment in West Germany serving as a platoon leader, intelligence staff officer, and C company commander. He returned to the United States and attended the Infantry Officer Advanced Course in 1979, making the Commandant's List. He taught in the Department of Mechanics at the United States Military Academy at West Point. While at West Point, Voss participated in a NASA Summer Faculty Research Fellowship and received the William P. Clements Jr. Award for Excellence in Education as the outstanding professor at the Academy. Voss then attended the U.S. Naval Test Pilot School, graduating with the Outstanding Student Award in 1983. He then attended the Armed Forces Staff College. Voss was subsequently assigned as a Flight Test Engineer/Research and Development Coordinator with the U.S. Army Aviation Engineering Flight Activity. He participated in major flight test programs before being assigned to NASA. At NASA, Voss worked at the Johnson Space Center from November 1984 to June 1987. He worked as a Vehicle Integration Test Engineer supporting the STS-51-D, STS-51-F, STS-61-C, and STS-51-L missions. After the "Challenger" accident, Voss participated in the investigation. He was selected by NASA as an astronaut candidate in June 1987.