A study has been performed which deals with the Earth tracking dynamics of a Radio Telescope Satellite (RTS) for motion in the plane of the orbit. This paper presents the results of this linearized dynamic stability analysis which is based upon attitude stabilization by passive gravity gradient control.
It is recognized that this analysis is preliminary in nature and merely represents a first, logical step in the analysis of the vehicle dynamics. Its principle value is that the model employed is optimistic and, therefore, if problem areas are found, they will, quite likely manifest themselves in a more complete study. This study has the added merit of providing some preliminary feeling for the problem with a relatively modest expenditure of effort.
To obtain the desired measurements of low frequency radio signals from outer space, the configuration is assumed to consist of a central spherical body with four tubular antennas extending 750 feet from it. Since the antennas represent extremely flexible elements, the emphasis in this analysis was placed upon investigating the potential stability problems caused by coupling between the rigid, central body motions and the relative motions of the flexible antennas.