Spacecraft inertial attitude and rate sensor control system

Abstract

Disclosed is a method and apparatus (1'; 1") for tracking a stellar body (22) using a telescope (9; 32) of a spacecraft (e.g., a satellite) (10; 10"). In accordance with an embodiment of the invention, the telescope (9; 32) is provided with gimbal supports (18a; 18b), and is maneuverable relative to the spacecraft (10; 10'). The stellar body (22) is acquired by the telescope (9; 32) so that the stellar body (22) is within the field of view (FOV) of the telescope (9; 32). After the stellar body (22) is acquired, an operation is performed for controlling the attitude of the spacecraft (10; 10') to within pre-established deadband limits, and, as a result, the spacecraft (10; 10') and telescope (9; 32) are each assumed to have a desired orientation relative to the stellar body (22). The stellar body tracking method of the invention is performed so as to maintain the telescope (9; 32) in an orientation wherein the stellar body (22) is within the field of view (FOV) of the telescope (9; 32), even if it occurs that one or more environmental disturbance forces impinge on the spacecraft (10; 10') and cause an undesired variation in the orientation of the spacecraft (10; 10') relative to the stellar body (22). The stellar body tracking method of the invention controllably points a pointing direction (line of sight) of the stellar body tracking system (1'; 1") independently of the spacecraft (10; 10'), for tracking the stellar body (22). In accordance with an aspect of this invention, spacecraft inertial position and rate information is derived for use in controlling the attitude of the spacecraft (10; 10'). In accordance with an embodiment of the invention, the pointing direction of the telescope (9; 32) is controllably pointed by maneuvering at least one of the telescope (9; 32) and a mirror (13") of the telescope (9; 32).

Dependencies are inferred from the claim text.