Following graduation from the Naval Academy in 1934, Merrill served in the battleship West Virginia (BB-48) and destroyers USS Brooks (DD-232) and USS Dorsey (DD-117). In 1937 he became a naval aviator, subsequently serving in Torpedo Squadron Three in the carrier USS Saratoga (CV-3) and in Utility Squadron One. In early 1942, after Merrill took an abbreviated postgraduate course in electrical engineering, Commander Delmar S. Fahrney selected him for the Special Design Branch of the Bureau of Aeronautics, where the Navy's first guided missiles were being developed. Throughout the war they were involved in a number of pilotless aircraft projects, including assault drones. After the war, Merrill traveled to Germany and brought back a number of rocket scientists to aid postwar U.S. development. Merrill was instrumental in the late 1940s in the establishment of the Naval Air Missile Test Center at Point Mugu, California, w he re a building is now named in his honor. Early tests included the Loon, a copy of the German V-1 buzz bomb, and the Lark, a surface-to-air missile developed by the Bureau of Aeronautics. In the mid-1950s Merrill was selected as the first technical director for the Polaris program. His oral history offers candid comments on the difficulties he had in working for Rear Admiral "Red" Raborn, who headed the Polaris program. Following his 1957 retirement from the Navy, Merrill worked in the defense industry and edited a series of books on guided missiles.