The Advanced Composition Explorer (ACE) spacecraft will require frequent attitude reorientations in order to maintain the spacecraft high gain antenna (HGA) within 3 deg of earth-pointing. These attitude maneuvers will be accomplished by employing a series of ground-commanded thruster pulses, computed by ground operations personnel, to achieve the desired change in the spacecraft angular momentum vector. With each maneuver, attitude nutation will be excited. Large nutation angles are undesirable from a science standpoint. It is important that the thruster firings be phased properly in order to minimize the nutation angle at the end of the maneuver so that science collection time is maximized. The analysis presented derives a simple approximation for the nutation contribution resulting from a series of short thruster burns. Analytic equations are derived which give the induced nutation angle as a function of the number of small thruster burns used to execute the attitude maneuver and the phasing of the burns. The results show that by properly subdividing the attitude burns, the induced nutation can be kept low. The analytic equations are also verified through attitude dynamics simulation and simulation results are presented. Finally, techniques for quantifying the post-maneuver nutation are discussed.
Optimal Attitude Maneuver Execution for the Advanced Composition Explorer (ACE) Mission
1995
11 pages
Report
Keine Angabe
Englisch
Astronautics , Spacecraft Trajectories & Flight Mechanics , Approximation , Attitude (Inclination) , Attitude control , Dynamic models , Explorer satellites , Ground based control , Mathematical models , Nutation , Optimal control , Spacecraft maneuvers , Thrust control , Angular momentum , Computerized simulation , Equations of motion , Ground operational support system , High gain , Spacecraft antennas , Thrust measurement
Optimal Attitude Maneuver Execution for the Advanced Composition Explorer (ACE) Mission
British Library Conference Proceedings | 1995
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