Stellar/inertial integrated guidance for responsive launch vehicles

Responsive space-lift is a new trend in space launches. It requires the guidance system of the launch vehicle to be easily prepared, precise, robust, and adaptive. The stellar/inertial integrated guidance system, which combines two distinct types of navigation data, has been successfully used for submarine-launched ballistic missiles. This paper focuses on its application for responsive launch vehicles. Only the prelaunch positioning and orientation errors are considered in order to provide a simple illustration of the basic principles, which can be conveniently generalized to practical launch activities with a well-developed optimum correction method. Error transition and measurement equations are constructed and two injection error correction schemes are proposed. Because the integrated guidance accuracy varies with regard to the stellar direction, an analytical method is addressed to determine the optimal navigation star. Finally, numerical studies are conducted and the results verify the integrated guidance policy. Stellar/inertial integrated guidance can simplify prelaunch preparation and improve the orbital injection accuracy. Thus, it provides an alternative that does not rely on man-made signals for responsive launch vehicles.