The WAC Corporal was the first sounding rocket developed in the United States and the first vehicle to achieve hypersonic speeds. It was an offshoot of the Corporal program, that was started by a partnership between the United States Army Ordnance Corps and the California Institute of Technology (named "ORDCIT") in June 1944 with the ultimate goal of developing a military ballistic missile. Development History The California Institute of Technology had been fostering a group of rocket enthusiasts known informally during the 1930s as the "suicide squad", which was financed by the Guggenheim Aeronautical Laboratory (GALCIT) since the mid-1930s. Some of the GALCIT enthusiasts had founded a business to manufacture rocket motors called Aerojet. During the first years of World War II, GALCIT had pursued the development of both solid and liquid-fueled Jet Assisted Take Off (JATO) boosters to aid aircraft take off performance. As the group had experimented with rockets for several years before the war they were selected by the Army to pursue ballistic rocket development. The first rocket designed by the group for the Army was designated as XFS10S100-A, also known as the Private, that being the first Army enlisted rank. The second ORDCIT project, which became the Corporal, named for the next Army enlisted rank, was a project originally named XF30L 20,000. The Corporal project envisioned a liquid propellant missile of diameter and a power of . The Signal Corps had created the requirement for a sounding rocket to carry of instruments to or higher. This was merged with a requirement of the Rocket R&D Division of the Ordnance Corps for a test vehicle. Frank Joseph Malina of the Jet Propulsion Laboratory (JPL) proposed the development of a liquid-fueled sounding rocket to meet this request, thus providing a practical developmental step towards the ultimate Corporal missile. The theoretical work setting the stage for the WAC Corporal was established in a 1943 paper "A Review and Preliminary Analysis of Long-Range Rocket Projectiles" by Malina and Hsue-Shen Tsien. Design was started by Frank Malina and Homer Joe Stewart to meet the Signal Corps' request with their study "Considerations of the Feasibility of Developing a 100,000-ft. Altitude Rocket." The final design work was done by a team of persons specializing in particular areas and involved significant efforts to derive performance from theoretical means (a relatively new method for America rocketry). The key persons responsible were M.M. Mills (booster), P.J.