On the design of rocket guidance equations for advanced missions

One of the major steps in the United States civilian space program beyond present day mission capability will be the development of the Space Transportation System (STS), a combination of booster and orbiter vehicles which will provide the capability to perform a wide variety of earth based advanced missions. In many ways, present day guidance techniques are incompatible or inefficient when considered for STS applications. The ascent-to-orbit maneuver and a broad class of orbital maneuvers are considered from a standpoint of pointing out deficiencies such as lack of throttle control capability and poor estimation accuracy of engine cutoff time in present day techniques. A number of guidance techniques that will overcome these deficiencies and have applicability to the particular STS mission requirements and constraints are developed. Additionally, for guided maneuvers based upon the repetitive solution to Lambert's problem, a method is presented whereby the accuracy of the Lambert solution and the implementation of cross product steering to obtain the thrust pointing direction are improved in relation to existing methods. The particular STS mission requirements and constraints are discussed in relation to designing the onboard guidance program, and a set of guidelines for evaluating guidance system performance is presented.