Roy’s first employer in the United States was the U.S. Navy Ordnance Laboratory, where he became deputy chief for aeroballistics research before leaving to become chief of the gas dynamics facility at the Arnold Research Organization (ARO), Tullahoma, Tennessee, where he worked from 1950 to 1957. In 1958 he joined the recently formed Lockheed Missiles and Space Company (LMSC) and stayed with Lockheed until his retirement in 1978.
His interest in wind tunnels at ARO sparked the development of high-temperature facilities at the LMSC research laboratories in Palo Alto, California, where he became director of research and was instrumental in turning that facility into one of the best of its kind in the aerospace industry. He moved on to become manager of the Discoverer space satellite system from 1959 to 1960, chief scientist from 1960 to 1962, and vice president and general manager of the space program division from 1962 to 1963.
From 1963 to 1978, Roy was chief scientist and a corporate vice president of the then-parent Lockheed Aircraft Corporation in Burbank, California. He was responsible for all corporate independent research and development, he established the Lockheed Research Council, and he arranged ties with other notable research facilities in the country, such as General Motors, Bell Laboratories, DuPont, and some U.S. Department of Defense establishments.
Roy was elected to the National Academy of Engineering in 1971 “for development of ingenious mathematical solutions to practical problems of aircraft and space vehicle design and testing.” He participated in a number of activities for the National Aeronautics and Space Administration (NASA) and the American Institute of Aeronautics and Astronautics (AIAA). He was a member of the NASA Committee on Space Vehicle Aerodynamics from 1955 to 1966 and chairman of the Research Advisory Committee on Space Vehicles from 1966 to 1973. He was chairman of the Research and Technology Advisory Council from 1973 to 1977. Concurrently, from 1970 to 1974 he chaired the Technical Advisory Board to the U.S. Department of Transportation. He was also an honorary fellow