The Army Air Force realized that rockets could be a very significant weapon in the air war. The preliminary results of the testing and development program demonstrated that the air-launched rocket could be an effective weapon against ground targets, especially those that were difficult for conventional bombers to reach. The ability of the rocket equipped fighter to move low over a target and release a rocket more directly at a target meant that a fighter aircraft could be a more versatile weapon than during the earlier periods of the war.
A series of meetings were held during the late fall of 1943 on the need to advance the Air Force involvement in rocket development. By early 1944, the Army Air Force was ready to create a special unit for the continued development of air-launched rockets. The Ordnance Department asked the Army Air Force Commanding General to create the unit at Dover Air Force Base on 25 January 1944. On 5 February 1944, the Assistant Chief of Air Staff wrote a memorandum to the Chief of Air Staff also recommending the creation of the unit at the Dover Air Force Base to coordinate the Army Air Force program. On 1 April 1944, the Commanding General of the Army Air Force ordered the establishment of an accelerated rocket development program with the creation of the base unit and experimental rocket station at Dover Air Force Base. The unit was formerly activated on 24 April 1944 as the 732nd Army Air Force Base Unit within the jurisdiction of the Army Material Command. The unit designation was changed to the 4146th on 31 August 1944. The Base Unit was to "study, evaluate, develop, fabricate, install and test all likely means of launching and aiming rocket propelled projectiles from aircraft as a means of improving the offensive or defensive fire power of Army Air forces aircraft."
Among those items that the Base Unit was to study were the use of the 4.5" launcher presently in production, use and the possibility of developing launchers for rockets up to 16" in diameter. The unit was also to develop rocket launchers for bombers and launchers for rockets that had flexible installation ability so that they could fire rockets forward and rearward. In addition, the Base Unit was to work on developing improved safety features such as blast deflectors and on increasing the number of rockets that could be fired from a single or multiple launching tubes. The Base Unit was also directed to examine and test foreign rocket devices including those developed by the U.S. Navy and the British, Russian, German, and Japanese Air Forces. Additional missions included the study and testing of retro or vertical bombs, German and Russian rocket bombs, and controlled rocket bombs.
The facilities constructed for the 4146th Base Unit at Dover Air Force Base consisted of an experimental station with a hangar (Hangar 1301), power plant, and shop area; an administrative building; the barracks area with housing and a mess hall; a hardstand and ammunition magazine area; and a range area.
The range was located near the Delaware River about ten miles from the base in the Bombay Hook area. The range had a precision firing section and a night explosive section. There was a clear buffer area around the range mostly consisting of open swamp land. There was an observation/control tower and a mess hall at the range.
The work in air-launched rockets conducted by the 4146th Base Unit was the beginning of a new type of air combat experience for American pilots and for combat pilots around the world. The rocket, while it did not end World War II faster or save lives, was part of a technological shift in combat which would be felt during the wars and combat actions of the Cold War era. Inexpensive and efficient rockets made it easier for smaller combat aircraft such as the early jets of the Korean Era to move against ground targets that would not have been accessible to traditional bombers. Also, the use of air-launched rockets in aerial combat meant that aircraft could stand off from each other during the engagement and fire at each other using electronic means to lock onto the target instead of using up-close visual sightings.