NASA Office of Logic Design

A scientific study of the problems of digital engineering for space flight systems,
with a view to their practical solution.

A Zero-Gyro Safemode Controller for HST

F. Landis Markley¹ and John D. Nelson²
¹NASA Goddard Space Flight Center
²Lockheed Missles & Space Company, Inc.

1992 AIAA Guidance, Navigation and Control Conference
August 10-12, 1992, Hilton Head Island, SC
A Collection of Technical Papers, Part 3, pp. 1445-1459
AIAA-92-4613-CP

Abstract

The purpose of this paper is to document the Zero-Gyro Sunpoint mode for Hubble Space Telescope, a safemode designed to ensure a power positivestate without the use of rate gyros. This paper presents an overview of the Zero-Gyro Sunpoint algorithm, followed by details of the algorithm, control system design, and simulation results. A new, related safemode test, the System Momentum Test, is also discussed.