First Tethered Satellite System: Satellite Gyro Drift On-Flight Identification

Abstract

This paper. to be considerad as an application of existing stochastic estimator theories, presents the design of ihe algorithm used to identify on flight the initial bias of the TSS-1 Satellite gyro drift rates. This algorithm utilises the Space Shutlle Orbiter as an inertial stable platform and correlates its residual angular rates with the satellite gyro package measurements (when the satellite is still latched on the Shutlle cargo bay). The drift rates nave been computed by means of a stocastic Maximum Likelihood Estimator (MLE) that processes the two data streams synchronized by an opportune cross-correlation function. The algorithm description, as implemented on the Mission Control Center (MCC) of the NASA JSC in Houston, on flight results and their comparison with the design simulation analysis and gyro package manufacturar ground calibration data, before and after the TSS-1 flight mission, are provided in the paper