To provide an onboard system accurately controlling an attitude, a solar array, and antenna direction pointing on the basis of sensed data on the onboard obtained from Earth, sun and other sensors by generating a current state vector including a position, velocity, etc., of a satellite and effectively executing position maintenance.

A satellite control data in the form of a state vector and a state vector product is formed to indicate the position and the geometric relationship of an aerospace vehicle in relation to the earth, the sun, the moon and a specified point on the earth. The data is used for controlling the attitude, SADA steerage, antenna direction pointing, momentum upload and earth sensor intrusion. An on-board orbit propagation predicts the data, and the data are integrated for jobs for various systems.