The ESA starmapper is an optical-electronic instrument, attached to a spinning spacecraft, and equipped with eight slits, each marking the times of passage of stars. The telemetered times of passage are fed into a linear, recursive, minimum variance, extended, square root, adaptive filter in order to obtain an accurate reconstitution of the spacecraft attitude and system parameters. A brief outline is presented of the mathematical modelling of spacecraft spin dynamics and the starmapper, and of the formulation of the filter. Computer simulations were carried out to investigate how accurately spacecraft attitude and certain spacecraft parameters could be reconstituted from given simulated star passage times. The simulations indicate the usefulness of the square root formulation of the filter, and of its adaptive mechanism. For small nutation angles of the spinning spacecraft, the attitude motion can be reconstituted with an accuracy of about one arcminute. As the nutation angle increases, this accuracy decreases and divergence may result.
Attitude Reconstitution of a Spinning Spacecraft Equipped with the ESA Starmapper
1977
9 pages
Report
Keine Angabe
Englisch