Attitude control of the Molniya I communication satellite which moves in a high eceentfic, periodically corrected orbit, and is continuously facing the Sun with its solar panels and the Earth with its antenna, is a difficult problem. It is shown that this problem may be solved by means of the multi-purpose usage of a speed modulated double-gimballed control moment gyro.
Development of the Earth's communication satellites encounters a number of specific problems particularly those in the design of the flight control system.
The control system has to automatically and practically permanently orient the solar panels to the sun and the parabolic antenna to the Earth.
Besides, by commands from the Earth, the orbit has to be periodically corrected.
Since the attitude control system must function continuously for over a year, use of the attitude-control thrust jets alone for the satellite angular position control would lead to inadmissible consumption of the propellant, always in short supply in space. Therefore more economical ways to maintain the proper orientation had to be sought. To maintain rotation of the satellite, as in case of the "Venus" craft [1], was not feasible since this would have eliminated the simultaneous, continuous orientation of the parabolic antenna to the Earth. Therefore attitude control by rotating masses was tried even though continual power consumption was required, but unlike the propellant, the power supply could be restored by solar cells.