Magnetic Eddy-Current Rotor for Spacecraft Spin Damping
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Solution Overview
Problem
Out-of-service spacecraft pose a risk as space debris due to high angular velocities, complicating capture and controlled re-entry, and existing capture techniques are hindered by rotational velocity, especially when connected via flexible links.
Innovation Solution
A passive magnetic damping device with a rotor and stator, utilizing eddy currents and magnetic suspension, aligns with Earth's magnetic field to control angular velocity, allowing for controlled re-entry and capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an out-of-service spacecraft is left in orbit, then it accumulates as space debris posing collision risks, but active removal operations are complicated by high angular velocity
Solution Approach 1:
The patent extracts the rotational control function from the main spacecraft body by introducing a separate rotor-stator magnetic damping device. The rotor, mounted on gimbals, is decoupled from the spacecraft structure, allowing independent angular velocity control without affecting the main spacecraft systems.
Solution Approach 2:
The patent replaces traditional mechanical braking systems with a magnetic damping mechanism. The magnetic field generated by the rotor interacting with the conductive stator creates eddy currents that produce damping torque, eliminating the need for mechanical contacts and complex braking mechanisms.
2Ease of manufacture
If a deorbiting satellite is used to capture debris, then controlled re-entry becomes possible, but high rotational velocity of the target satellite limits capture success
Solution Approach 1:
The patent applies preliminary action by reducing the spacecraft's angular velocity before the capture operation. The magnetic damping device is activated in advance to dampen rotations, ensuring the spacecraft is in a stable state when the deorbiting satellite attempts capture, thereby increasing mission success probability.
Solution Approach 2:
The magnetic damping device acts as an intermediary between the spacecraft's rotational motion and the capture operation. It mediates the high angular velocity that would otherwise prevent successful capture, transforming the unstable rotational state into a stable one suitable for safe capture and controlled re-entry.
3Adaptability or versatility
If flexible links are used to connect deorbiting satellite to debris, then capture is enabled, but high angular velocity creates incompatible operational conditions
Solution Approach 1:
The patent extracts the rotational stabilization function from the flexible link system by implementing it in the target spacecraft itself. The magnetic damping device is mounted on the debris spacecraft, independent of the flexible connection, providing stabilization without constraining the link's flexibility or requiring complex control of the connection mechanism.
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
Facilitates the active removal of out-of-service spacecraft by reducing angular velocity, enabling safe re-entry and capture without additional propellants, and allowing ground testing of the device.
Implementation Method 1
the rotor comprises a magnetized system configured to induce, in the stator, eddy currents for braking a relative movement of the rotor with respect to the stator and to create a magnetic moment in the Earth's magnetic field
Implementation Method 2
The rotor further comprises one (or more) magnetic-suspension magnets intended to cooperate with a magnetic field generated by a source external to the device in order to suspend the rotor magnetically with respect to the stator
Implementation Method 3
the rotor comprises a magnetized system configured to induce, in the stator, eddy currents for braking a relative movement of the rotor with respect to the stator
Data Source
AI summary
A device (1) for controlling the angular velocity of an out-of-service spacecraft including: a stator (3) and a rotor (4) movable about an axis (A21) of rotation with respect to the stator. The stator (3) includes an electrically conductive and non-ferromagnetic body (6) while the rotor (4) includes a magnetized system (7) configured to induce, in the stator (3), eddy currents for braking a relative movement of the rotor (4) with respect to the stator (3); and a magnetic-suspension magnet (11) configured to cooperate with a magnetic field generated by an external source to suspend the rotor (4) magnetically with respect to the stator (3). The device (1) includes one or more non-ferromagnetic materials in a zone (11ZI) of influence of the magnetic field generated by the magnetic-suspension magnet.