camera had to be able to survive recovery, rather than the entire rocket. The unique innovations of the Hiroc missiles, such as the gimbaled thrust chambers, and the internal pressure supported airframe, would go on to utilized in the Atlas rockets. Several changes were made in the Atlas, such as the aluminum used for the missiles airframe of the Hiroc, was changed to stainless steel in the Atlas. The early Atlas utilized the MX-774 project developed Azusa interferometry based guidance system which served Cape Canaveral during the early space age. The engines of the Atlas missiles were also much more powerful, generating a total of of thrust, compared to the Hiroc's total of thrust. History In April 1946, Convair received a 1.9 million dollar contract from the US Government under Air Material Command designation Material, Experimental-774B (MX-774B) to investigate the development of ballistic missiles. This was one of a large number of missile projects being studied by the US Army at that time, which included both ballistic missiles and a variety of long-range cruise missiles as well. The original of MX-774B called for a missile that could deliver a payload , and which had an accuracy that allowed it to deliver it to within of the target. The MX-774B project was headed by Karel Bossart, who would go on to head the creation of the Atlas rockets. Although development of the specification MX-774B was inspired by the German V-2 the MX-774B introduced several significant innovations, such as an integrated propellant tank, swiveling engines, pressurized body, and detachable nose cone. As a result of drastic defense cuts in 1946 and for 1947 the USAAF's missile budget was cut in half from $29 to $13 million in what became known as "the black Christmas of 1946". Many of the projects were canceled outright, but MX-774 instead continued with reduced funding. The project was eventually canceled in June 1947 as the Army concentrated their efforts on cruise missiles, which were more promising at that time. Convair arranged to use the remaining contract funding to launch three of the rockets, which were named RTV-A-2 Hiroc. The tests took place at White Sands Proving Grounds. The three tests took place on 13 July 1947, 27 September, and 2 December. These tests validated the concept of using gimbaled engines for propulsion and guidance. Hiroc was flown from a pad 600 feet north the White Sands blockhouse.