In 1942, the US Navy sponsored the development of an aerial rocket that could defeat light armor and bunkers. By 1944, Caltech (California Institute of Technology) introduced the 5-inch 'High Velocity Air Rocket' or Hi-VAR.
The Hi-VAR was 6 feet long and weighed 140 pounds. It had fixed fins and was carried on streamlined stub pylons under the wings of aircraft such as the Hellcat and Corsair, as well as the Thunderbolt or Mustang. It had a steel-cased warhead and could penetrate nearly two inches of plate armor or four feet of reinforced concrete.
Pilots often called the Hi-VAR the 'Holy Moses' because of its impressive destructive effect. The rocket was used in all combat theaters, including attacks on ships.