Spacecraft Attitude Maneuver and Momentum Dumping Integration
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Solution Overview
Problem
Current spacecraft systems require separate phases for attitude maneuvering and momentum dumping, which consume valuable orbital time and propellant, and introduce perturbations to the nominal maneuver and trajectory.
Innovation Solution
A system and method that computes thruster commands to apply de-saturation torques simultaneously during spacecraft maneuvers, using reaction wheels and control moment gyroscopes, enabling thrusters to de-saturate wheels while slewing, thereby optimizing mission operation time and minimizing propellant usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate phases are used for attitude maneuvering and momentum dumping, then the spacecraft can complete both operations, but orbital time is consumed and propellant usage increases
Solution Approach 1:
The patent combines attitude maneuvering and momentum dumping into a single integrated operation. The control system simultaneously commands the reaction wheels to perform attitude maneuvers while commanding thrusters to apply de-saturation torques to dump accumulated momentum, eliminating the need for separate phases and reducing total orbital time required.
Solution Approach 2:
The system maintains continuous useful action by overlapping the momentum dumping process with the attitude maneuver execution. Rather than completing one operation before starting the other, both operations proceed concurrently with coordinated control inputs, maximizing the utilization of orbital time for productive operations.
2Reliability
If separate phases are used for attitude maneuvering and momentum dumping, then the spacecraft can complete both operations, but propellant consumption increases
Solution Approach 1:
The patent merges attitude maneuvering and momentum dumping into a single integrated operation. The control system simultaneously commands the reaction wheels to perform attitude maneuvers while commanding thrusters to apply de-saturation torques to dump accumulated momentum, eliminating the need for separate phases and reducing total orbital time required.
Solution Approach 2:
The system applies partial thruster firing during the attitude maneuver to achieve sufficient momentum dumping without requiring full de-saturation cycles. By applying just enough de-saturation torque to prevent wheel saturation during the maneuver, the system reduces propellant consumption compared to traditional complete momentum dumping approaches.
3Reliability
If separate phases are used for attitude maneuvering and momentum dumping, then the spacecraft can complete both operations, but perturbations are introduced to the nominal maneuver and trajectory
Solution Approach 1:
The control system acts as an intermediary that coordinates between the attitude maneuver commands and momentum dumping commands. By computing integrated control inputs that account for both objectives simultaneously, the system smooths out disturbances and prevents the introduction of perturbations to the nominal maneuver and trajectory that would result from sequential operations.
Solution Approach 2:
The system performs preliminary computation of integrated control commands that anticipate the interaction between attitude maneuvers and momentum dumping. By pre-coordinating the control inputs before execution, the system prevents disruptive perturbations from occurring during the actual maneuver execution.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for efficient use of orbital maneuver time, reduces propellant consumption, and minimizes perturbations to the spacecraft's time and trajectory by integrating momentum dumping with attitude maneuvers.
Implementation Method 1
reaction wheel speed and/or control moment gyroscope (CMG) gimbal position and wheel speed is determined
Implementation Method 2
control moment gyroscope (CMG) gimbal position and wheel speed is determined
Implementation Method 3
compute spacecraft (S/C) thruster commands to apply de-saturation torques
Data Source
AI summary
A system and method are disclosed for simultaneous attitude maneuver and momentum dumping. The attitude maneuver is performed using nominal wheel control to minimize propellant usage, while applying a momentum management command to the thruster control loop in order for the wheels to accomplish the desired spacecraft maneuver while simultaneously being reset to a de-saturated target state. The system and method involve a wheel system comprised of reaction wheels and/or a control moment gyroscope (CMG), at least one thruster, and control logic that is in communication with the wheel system and thruster(s). If a spacecraft maneuver is in progress, the control logic biases an error input signal to a thruster control loop to track the wheel maneuver to prevent unnecessary propellant consumption. The control logic is further operable to output thruster torque commands and wheel torque commands that accomplish the maneuver while achieving the desired final momentum target.