White Sands, New Mexico
After his masters, Singer joined the armed forces, working for the United States Navy on mine warfare and countermeasures from 1944 until 1946. While with the Naval Ordnance Laboratory he developed an arithmetic element for an electronic digital calculator that he called an "electronic brain". He was discharged in 1946 and joined the Upper Atmosphere Rocket Program at the Johns Hopkins University Applied Physics Laboratory in Silver Spring, Maryland, working there until 1950. He focused on ozone, cosmic rays, and the ionosphere, all measured using balloons and rockets launched from White Sands, New Mexico, or from ships out at sea. Rachel White Scheuering writes that for one mission to launch a rocket, he sailed with a naval operation to the Arctic, and also conducted rocket launching from ships at the equator.