Patent ID: 6213432
Filing Date: 2001-04-10
Classification: B64G

Abstract:
A system for placing a space vehicle, such as a satellite, on a target orbit such as that adapted to normal operation of the space vehicle and starting from an elliptical initial orbit that differs substantially from the target orbit, and in particular that has eccentricity that is different from that of the target orbit, the system comprising:a set of platforms mounted on the space vehicle;a set of thrusters mounted on said platforms and having high specific impulse, greater than 5000 Ns/kg, and low thrust, less than 10 N, to create a total thrust force applied to the space vehicle;a control device for putting the thrusters into continuous operation after the space vehicle has been placed on its initial orbit so as to enable said space vehicle to reach a target orbit via a completely spiral trajectory, ignoring possible service interruptions, and to stop the thrusters firing when the apogee altitude, the perigee altitude, and the orbital inclination of an intermediate orbit of the space vehicle are substantially equal to the values of the target orbit; anda thrust direction control device comprising at least first means for operating, during a first stage of continuous firing of the set of thrusters, to generate first control signals for aiming total thrust such that on each successive revolution of the space vehicle and in each intermediate orbit, apogee altitude increases, perigee altitude increases to a lesser extent, and any difference in the inclination of the intermediate orbit relative to the target orbit is decreased, and at least second means for operating, during a second stage of the set of thrusters firing, to generate second control signals for aiming total thrust such that on each successive revolution of the space vehicle and in each intermediate orbit, apogee altitude decreases, perigee altitude increases, and any difference of inclination between the intermediate orbits and the target orbit decreases.