Altitude Simulation in Saturn S-IV Stage Testing

The Douglas Aircraft Co. has been involved in testing the Saturn S-IV stage at the Sacramento Test Center for the past two years. The propulsion system for the S-IV stage consists of six Pratt & Whitney Aircraft Co. rocket engines specifically designed for high-altitude start and operation. During static firing tests of this engine at sea level, a steam jet ejector in combination with a diffuser is used to simulate altitude conditions. The intent of this paper is to examine the performance of this altitude simulation system, and to discuss the problems encountered in making it operational.