Cavitating Pump Dynamics Test Facility for Vehicle System Stability Modeling

A unique cavitating pump dynamics test facility has been developed at Concepts NREC (CN, White River Junction, VT) in cooperation with engineers at NASA Marshall Space Flight Center (Huntsville, AL). Its purpose is to determine pump dynamic transfer functions for use in vehicle system stability modeling and analysis. This analysis is vital to ensure that future space launch vehicles do not exhibit self-excited longitudinal oscillations, also known as “Pogo” — so named because the phenomenon vibrates the rocket up and down in a manner similar to bouncing on a pogo stick. The vibrations severely impair the astronauts’ ability to pilot or respond to emergencies and can cause structural failure of the vehicle. NASA first became aware of the disastrous consequences from Pogo during the Gemini-Titan program, and continued to be plagued by it through the Saturn V Moon launch missions.