Abstract: Microgravity sensitive payloads placed on a platform are isolated from external acceleration forces over extended periods of time in the weightless environment inside an orbiting space vehicle by canceling acceleration on the platform. Wide gap dual axis magnetic actuators and accelerometer pairs are spaced about the platform with the magnetic actuators providing a non-contacting magnetic position control, wherein physical contact with the platform is avoided. Position sensors sense platform positioning and the control system, containing both digital and analog computers, controls the magnetic actuators to ensure proper positioning and neutralize any transient acceleration forces applied to the platform.

Abstract: A system for providing a stable caging loop for two-degree-of-freedom dry tuned gyros used in a strap-down inertial navigation system. The system provides satisfactory noise rejection and good navigation accuracy using cross axis torquing only with extremely simple analog shaping circuits in place of the combination of cross axis and direct axis torquing with complex shaping circuitry that is normally required with these gyros in such an application. A 64 Hz bandwidth loop is provided with less than 1.degree. phase lag below 5 Hz, 10 db attenuation of rotor spin rate noise, and at least 35 db attenuation of all higher frequencies. Its performance is such that it can be used in a navigation system requiring accuracy on the order of one nautical mile per hour in a typical missile environment.