USING ELECTRODYNAMIC SHAKERS TO SIMULATE PULSED FIRINGS OF THE ORBITER REACTION CONTROL SYSTEM

摘要

The Space Shuttle Orblter Reaction Control System (RCS) consists of one forward RCS module and two aft RCS subsystems in the Orbital Maneuvering System (OMS) pods. These Include 38 main thrusters and 6 vernier thrusters used to adjust the Orbite's attitude when on orbit A series of tests were performed in the Vibration and Acoustic Test Facility (VATF) at the NASA Johnson Space Center in Houston, Texas, on a quarter scale model of the Orblter, to simulate various combinations of firings of the RCS to determine the effect of the firings on various payload attach points on the longerons and keel. A major part of the test program was the development of a method of using etectrodynamic shakers to provide a square pulse to simulate the firing of the RCS. However, considerable development was required to determine the appropriate voltage signal to send to the shaker that would result in the desired square pulse at the test article. The purpose of this paper is to present the development of the method used to generate a square pulse using an electrodynamic shaker as well as some of the results of that test.