Device for Generating Variable Angular Momentum Using Magnetically Moved Fluid for Attitude Control of Spacecraft
Abstract
Mechanics-free attitude control: A magnetizable fluid is moved along closed paths using dynamic magnetic fields, stores angular momentum, and transfers torque precisely to the spacecraft.
Advantages
- Mechanics-free; low wear, high expected lifespan, and reliability.
- No reliance on external magnetic fields or fuel logistics; principle enables unlimited operational duration.
- Simple, cost-effective manufacturing without high-precision rotating components.
- Potential for low vibrations and noise compared to mechanical systems.
Fields of application
- Spaceflight: Attitude control, angular momentum storage, reaction wheel desaturation, fine positioning.
- Onboard subsystems: Flow and substance transport without mechanics (valves, pumps, mass-flow control) as a technology platform; transferable from PAPELL demonstrations.
- Long-term: Lab-on-chip/conveying technology in space, gentle transport of multiple media in shared lines.
Background
Attitude control systems in spaceflight require reliable actuators for angular momentum provision and modulation. Conventional solutions (reaction/momentum wheels, magnetic torquers, thruster pulses) have drawbacks such as wear, dependence on external magnetic fields, or fuel consumption.
Problem
Need for low-wear, cost-effective, and universally applicable attitude control actuators that operate without high-precision mechanics, external magnetic fields, or fuel.
Solution
A container with magnetizable fluid (e.g., ferrofluid) and a controllable field generator creates locally migrating zones of high magnetic field strength, guiding the fluid along closed paths. Stored angular momentum is varied by changing the fluid flow speed and torque is transferred precisely to the carrier structure (spacecraft).
Figure: Feerowheel-Liquid In and Outrunner [IRS, University of Stuttgart]