May 7, 1946: Jet Propulsion Laboratory Launched Models of the Corporal E Missile

  • Published
  • Air Force Flight Test Center

The Jet Propulsion Laboratory (JPL) launched 1/5 scale models of the Corporal E missile from its facility at the northern edge of Rogers Dry Lake. The scaled-down test models were fired from an upright rail structure to demonstrate the possibility of zero-speed vertical launch with no jet vanes. The full-sized Corporal was a surface-to-surface missile with a designed range of approximately 60 miles.

he ORDCIT (US Army’s Ordnance and California Institute of Technology) program to develop a ballistic missile called Corporal was a progressive one. The original design was called XF30L20,000 which envisioned a 30 inch diameter liquid fueled missile with a 20,000 lbf thrust engine and was ventured in the summer of 1944. The WAC Corporal sounding rocket was developed in 1945, providing experience with liquid fueled ballistic rocketry. The second phase gave experience with a redesigned and refined rocket and engine the following year. What was learned was applied to the Corporal program.  The major development problems that were to be encountered with the XF30L20,000 were guidance and the increased size of the rockets engine.  The original time schedule was excessively optimistic especially as it envisioned the development of a turbo pump for propellants.  The biggest problem was guidance as it was essentially unbroken ground. To provide as much data as possible a telemetry system was required. It was determined that an autopilot guidance system was required and that a means of radio guidance to control roll, pitch and yaw, would also be needed.  Graphic mapping of the missile’s flight would be performed by two radar plotting boards.  The guidance system of the first few rounds of Corporal E were to be supplied by Sperry Gyroscope Company largely from existing units because of the time required to develop special units.  Primary control was to be via vanes extending into the rocket exhaust. Ten channels of telemetry were envisioned to be displayed on graphic recorders to provide data to the missile operators. It was the intent of the people conducting the program to have the capability to control the rocket’s flight with a control stick to observe flight characteristics. The intent was following the first few flights to have the operator hit a predetermined target.  At the end of WWII the Corporal E programs adjusted to a less ambitious schedule and the WAC Corporal program was adjusted to provide more experience and design information.  Work on the Corporal F with turbo pump instead of compressed air pressure propellant feed was halted with few parts produced and the Corporal G study of a chemical gas generator to pressurize the fuel tanks was terminated as well.  The Corporal E was designed by JPL, with the first 4 airframes built by Douglas Aircraft Company, rocket motors and telemetry equipment were produced by JPL, Sperry Gyroscope provided the autopilot, Army Ordinance the Doppler and Position transponder, and the Signal Corps the radar tracking beacon.