Constellation design for responsive visiting based on ground track adjustment

Abstract

Many responsive civilian or military space missions require that a certain ground site of interest be visited in a fairly short period (e.g., 12 h or less). To this end, a constellation must be utilized, since a single satellite is usually unable to fulfill such a task if the ground site is selected on the whole terrestrial surface responding to random user requirements. In this paper, the design approaches of such a constellation for responsive visiting based on ground track adjustment are investigated. By using the difference in orbit period between the maneuvered satellite and the reference satellite to make the ground track shift, reachable domain belts are generated. In terms of orbit maneuvering, two- and one-impulse maneuvers are analyzed and compared. Based on the reachable domain belts of a single satellite, two constellation design methods are proposed. The first one is an analytical method which is presented to achieve global reach and implemented by uniformly splicing together the widest belts of all satellites within the range of [0°, 180°]. The second one is an optimized method proposed to further reduce the number of satellites, by splicing together all the reachable domain belts rather than only the widest belts in the equator. A hybrid algorithm that consists of the genetic algorithm and the pattern search algorithm is proposed to minimize the number of satellites. Numerical examples are provided to illustrate the two proposed constellation design methods and validate the global reach performance.