Spacecraft flywheel systems-benefits, and issues

Flywheels are electro-mechanical energy storage devices. Recent developments in magnetically levitated composite flywheels have produced systems with specific energies in excess of 20 watt-hours/pound. When compared with nickel-hydrogen battery technology, flywheels offer significant weight savings as an energy storage media for spacecraft. Additional weight savings are possible if the flywheel hardware can also be used for on-board attitude control and momentum management. This paper explores the challenges which accompany the insertion of flywheel systems into spacecraft power and attitude control subsystems.