The Boeing Company

Other

Kangsik Lee

Timothy S Lui

Che-Hang Charles Ih

Glenn N Caplin

Gary E Lemke

Qinghong W Wang

Alexander Jacob Sobel

Troy Allen Fontana

Arunkumar Pursayya Nayak

Energy efficient satellite maneuvering is described herein. One disclosed example method includes maneuvering a satellite that is in an orbit around a space body so that a principle sensitive axis of the satellite is oriented to an orbit frame plane to reduce gravity gradient torques acting upon the satellite. The orbit frame plane is based on an orbit frame vector.

Energy efficient satellite maneuvering

Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a propulsion subsystem with electric thrusters that are installed with two-axis gimbal assemblies. The spacecraft also includes a controller that identifies a target spin axis for the spacecraft, determines an actual spin axis for the spacecraft during the transfer orbit, determines gimbal angles for the electric thruster(s) that adjust the actual spin axis toward the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles.

Reorientation of a spinning spacecraft using gimbaled electric thrusters

Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a momentum subsystem that stores angular momentum relative to a center of mass of the spacecraft, and a propulsion subsystem that includes electric thrusters. A controller identifies a target spin axis for the spacecraft, determines gimbal angles for electric thruster(s) that so that thrust forces from the electric thrusters are parallel to the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles. The controller controls the momentum subsystem to compensate for a thruster torque produced by the burn of the electric thrusters. The momentum subsystem is able to produce a target angular momentum about the center of mass, where a coupling between the target angular momentum and an angular velocity of the spacecraft creates an offset torque to counteract the thruster torque.

Spin stabilization of a spacecraft for an orbit maneuver

Apparatus and methods for attitude control of a space vehicle. The space vehicle includes a reaction wheel subsystem and a propulsion subsystem for attitude control. A slew controller for the space vehicle detects a failure of the reaction wheel subsystem. To perform an attitude slew, the slew controller identifies a pair of thrusters in the propulsion subsystem that will rotate the space vehicle about a desired axis. The slew controller determines burn parameters for the pair of thrusters, and initiates the burns to perform the desired attitude slew.

Attitude slew methodology for space vehicles using gimbaled low-thrust propulsion subsystem

A system and method are disclosed for an innovative spacecraft (S/C) safing methodology. The system and method use wheel momentum to perform a rotisserie rotation so that the spacecraft can slew at a fast rate in a controlled fashion in order to keep the spacecraft power safe and maintain telemetry and command (T&C) coverage. The system and method involve a reaction wheel system and a spacecraft control processor (SCP). The SCP is in communication with the reaction wheel system. The SCP is operable to determine a rotisserie axis, and take the cross product of the rotisserie axis and a momentum vector to result in a unit vector. The SCP is further operable to slowly slew the spacecraft about the unit vector through an angle until the rotisserie axis aligns with the momentum vector, and rotate the spacecraft about the rotisserie axis to keep the spacecraft power safe.

Innovative optimal spacecraft safing methodology

Spacecraft control modules can steer a spacecraft during a slew maneuver. The spacecraft control modules can receive a target attitude for the spacecraft slew maneuver. An angle between a current attitude and the target attitude may be determined. A smooth attitude offset profile with respect to a steering frame may be established from the current attitude to the target attitude. A smooth attitude command may be generated from the smooth attitude offset profile. The smooth attitude command may be applied to an attitude control module of the spacecraft.

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Torrance, CA, United States of America

Kangsik Lee