Solar torque compensation for a satellite

Abstract

A satellite is compensated for torques caused by solar pressure on a solar panel extending from the satellite by an air core coil energized to develop a magnetic torque in opposition to the solar pressure torque. The coil is disposed generally in the periphery of the solar panel mounted externally to the satellite. The energizing current is fixed or varied by ground command or automatically in a closed loop system to compensate for variations in the earth's magnetic field.

What is claimed is: 
     
       1. An attitude control system for a .[.spin.]. stabilized spacecraft to compensate for torques due to solar pressure, said spacecraft having a panel with a set of solar cells adapted to receive solar radiant energy for conversion to electrical power, said panel being arranged for deployment from the spacecraft including means for orienting the panel toward the sun, the improvement comprising: a. electromagnetic means included in said panel for generating a magnetic flux having a magnetic field extending normal to the plane of said panel for reacting with the magnetic field of the earth, said electromagnetic means comprising a single electromagnetic air core coil having at least one turn of wire disposed in the peripheral portion of said solar cell panel, and in a plane parallel with the plane of said solar panel, and   b. means for energizing said electromagnetic means in response to solar energy received on said solar panel such that a magnetic flux therefrom reacts with the magnetic field of the earth to produce a magnetic torque substantially of equal magnitude and opposite direction to the torque developed on said spacecraft by the solar pressure of the solar radiant energy on said panel.   
     
     
       2. A system according to claim 1 wherein said energizing means includes means for connecting said solar cells and said coil in parallel. 
     
     
       3. A system according to claim 1 wherein said energizing means includes means for connecting said solar cells and said coil in series.