Study of double gimballed momentum wheels in the attitude and orbit control system of a geostationary communication satellite

The potentials of a double glmballed mcwientum wheel as an actuator for the attitude oontrol of a geostationary communication satellite are discussed with respect to the related systems. A justification of the IXaW is given and the characteristics defining the wheel system are determined. They can serve to be the input to a detailed design of an...

Factors influencing the choice of an orbital propulsion system for geostationary satellites

In this report the requirements of orbit control of geostationary communications satellites are investigated. A comparison between chemical and electrical propulsion is made for mission lives up to I5 years. The mass of electrical propulsion is lower than of chemical syetems, even when mass penalties for the low reliability of the ion thrusters...

Stability of double gimballed momentum wheels

Due to the finite stiffness of rotor- and gimbal-suspensions, a double gimballed momentum wheel will oscillate with high natural frequencies. The stability of these oscillations is studied, in order to obtain requirements for the stiffness of the suspensions and/or the gimbal inertia properties. From energy considerations, it is concluded that...

Accuracy of attitude control systems for satellites using double gimballed momentum wheels

Preparatory study of satellite attitude control with momentum wheels

Preparatory study of satellite attitude control with momentum wheels

In this study a survey is given of laimched satellites, paying special attention to mission objectives and attitude control systems. This picture is extrapolated into the near future to analyse the control requirements that are to be expected for future satellite missions. Possible attitude control systems for satellites are also surveyed and...

Behaviour of sounding rockets at high altitude

At high altitude a rolling sounding rocket makes a so-called coning motion, in which the longitudinal axis of the rocket describes a cone around an axis which is fixed in space. Starting from a complete set of equations of motion, an analytic expression is developed for the cone half angle and for the direction of the cone axis in space for a...

Comparison of the impact dispersion of unguided and guided sounding rockets with further evaluation of a velocity controlled rocket

A comparison is made between unguided rockets, attitude stabilized rockets and rockets with control of the horizontal velocity components, all with one or two stages. Special emphasis is placed on impact dispersion, which is treated analytically. The best system appears to be a two stage rocket with unguided first stage and velocity control on...