Spacecraft Momentum Management via Thruster Coordination
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Solution Overview
Problem
Current spacecraft momentum management techniques require significant propellant for station-keeping and delta-V maneuvers, which reduces spacecraft life and increases launch costs.
Innovation Solution
Adjusting the momentum storage deadband limits in relation to delta-V maneuver windows to bias thruster firings, allowing desaturation of momentum/reaction wheels to provide velocity changes beneficial or detrimental to the maneuvers, thereby optimizing propellant use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional momentum management techniques are used to desaturate momentum wheels, then attitude control is maintained, but significant propellant is consumed for station-keeping maneuvers
Solution Approach 1:
The patent combines momentum wheel desaturation operations with station-keeping maneuvers by coordinating thruster firings to achieve both objectives simultaneously. The momentum management system is merged with the orbit control system, allowing the same thruster impulses to both dump accumulated momentum from reaction wheels and perform necessary station-keeping velocity changes, thereby eliminating redundant propellant consumption.
Solution Approach 2:
The thruster system is made multi-functional by enabling it to perform both momentum desaturation and station-keeping maneuvers. The control system determines when a single thruster firing can simultaneously satisfy both the momentum wheel desaturation requirement and the station-keeping delta-V requirement, making the propulsion system universally applicable to multiple control functions.
2Stability of the object's composition
If momentum desaturation is performed frequently to maintain attitude control, then attitude stability is improved, but propellant consumption increases
Solution Approach 1:
The patent implements dynamic adjustment of momentum management parameters by continuously monitoring the spacecraft's momentum accumulation rate, orbital position, and station-keeping requirements. The system dynamically determines the optimal timing and magnitude of desaturation events, adjusting the momentum wheel speed setpoints and thruster firing commands in real-time to maintain attitude stability while minimizing propellant usage based on current operational conditions.
Solution Approach 2:
The control system changes operational parameters such as momentum wheel speed limits, deadband thresholds, and thruster firing windows to optimize the balance between attitude stability and propellant consumption. By dynamically adjusting these parameters based on the spacecraft's operational state and orbital position, the system maintains sufficient attitude control while reducing unnecessary desaturation events.
3Quantity of substance
If thruster firings are used to desaturate momentum wheels, then momentum is unloaded, but velocity changes may be detrimental to upcoming delta-V maneuvers
Solution Approach 1:
The patent implements a feedback-based control system that monitors the spacecraft's orbital state, momentum wheel status, and upcoming maneuver schedule. The system uses this feedback information to predict the impact of potential desaturation events on future delta-V maneuvers and adjusts the desaturation timing and magnitude accordingly, ensuring that momentum unloading does not compromise the efficiency of planned velocity change maneuvers.
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 reduces propellant consumption by aligning thruster desaturation with delta-V maneuvers, enhancing spacecraft longevity and lowering launch expenses.
Implementation Method 1
at least one momentum/reaction wheel configured to maintain the attitude with respect to an axis by storing momentum
Implementation Method 2
These control torques may be provided by firing one or more thrusters that are directed such that a resulting thrust vector defines a moment arm with respect to the satellite's center of mass
Data Source
AI summary
Spacecraft momentum management techniques are coordinated with station-keeping maneuvers or other delta-V maneuvers. A body stabilized spacecraft attitude is controlled, the spacecraft including at least one momentum/reaction wheel, and a set of thrusters. A first momentum storage deadband limit is adjusted, the adjustment being related to a first delta-V maneuver window. A momentum management strategy is executed with the adjusted first momentum storage deadband limit such that a first thruster firing that performs desaturation of the momentum/reaction wheel also provides velocity change beneficial to the first delta-V maneuver.