Singer had a varied career, serving in the armed forces, government, and academia. He designed mines for the U.S. Navy during World War II, before obtaining his Ph.D. in physics from Princeton University in 1948 and working as a scientific liaison officer in the U.S. Embassy in London. He became a leading figure in early space research, was involved in the development of earth observation satellites, and in 1962 established the National Weather Bureau's Satellite Service Center. He was the founding dean of the University of Miami School of Environmental and Planetary Sciences in 1964, and held several government positions, including deputy assistant administrator for the Environmental Protection Agency, and chief scientist for the Department of Transportation. He held a professorship with the University of Virginia from 1971 until 1994, and with George Mason University until 2000.