A Self-Contained Interplanetary Navigator

This paper is concerned primarily with various methods that can be used to mechanize a self-contained space navigation system, using a positional perturbation guidance equation to compute velocity corrections. The key components involved are those used to determine present position, a control system to implement velocity corrections, and a computer to interrelate their functional operations. In the area of determining present position, various schemes are described for obtaining a celestial fix. These include purely-optical and inertial-optical schemes, which are compared. In addition, a least-squares data smoothing criterion is shown whereby position is computed using redundant fix data. The implementation of velocity corrections is largely dependent upon the ability to accurately control vehicle attitude and to measure the magnitude of the velocity increment. Therefore, various schemes are proposed for controlling the direction and magnitude of a velocity correction.