PROCEDE ET DISPOSITIF D'INJECTION DE SATELLITE SUR ORBITE GEOSTATIONNAIRE AVEC STABILISATION SUIVANT LES TROIS AXES

摘要

1. A method of injection into a geostationary orbit of a satellite stabilized around three axes and carrying an Earth sensor, a sensor of a heavenly body near the equatorial plane, two gyrometers (24, 26) for measuring rotation around the roll axis (GX) and the yaw axis (GZ) of the satellite and attitude control means such as thrusters, the Earth horizon sensor being so disposed that its field of view does not include the Earth when the apogee booster is ignited, the heavenly-body sensor being disposed substantially along the roll axis of the satellite, the method being characterized in that it comprises the following steps : (1) the satellite is rotated around an axis directed towards the heavenly body until the Earth enters the field of the Earth horizon sensor and the satellite (10) is stopped in a position such that its yaw axis (GZ) corresponding to the direction of thrust of the apogee booster (16) is directed towards the Earth, (2) the yaw axis of the satellite is kept parallel to its original position for a sufficient time to measure the drift of the gyrometers (24, 26), (3) if required the yaw axis of the satellite is brought back into alignment with the Earth, after which the satellite is rotated around the yaw axis while retaining the Earth reference by means of the Earth horizon sensor (18), until the pitch axis (GY) is in a predetermined set position perpendicular to the plane of the transfer orbit except for the correction for returning to the equatorial plane, arrival in the set position being determined by the heavenly-body sensor (22) without use of the gyrometers, and (4) the apogee booster is brought into the firing orientation by rotating the satellite around the pitch axis, arrival at the firing orientation being determined by the heavenly-body sensor, the gyrometers (24, 26) being then used as detectors at zero speed.