Flywheel Energy Storage as an Alternative for Chemical Batteries in Small LEO Satellites: Feasibility and Attitude Impact

Given the accelerating increase in the number of satellites, mainly driven by the deployment of large constellations, manufacturers are under growing pressure to innovate in order to reduce both costs and environmental impact. In this context, the present work investigates the feasibility of replacing chemical batteries on Low Earth Orbit (LEO) satellites with mechanical storage systems based on flywheels. Flywheel Energy Storage Systems (FESS) can offer a significantly higher depth of discharge (easily up to about 75%) compared to conventional chemical batteries (10-20%), thereby enabling reductions in both mass and volume. Despite these advantages, the angular momentum inherent to flywheel operation will significantly perturb the spacecraft’s attitude dynamics, posing a major challenge for attitude control. The objective of this study is to develop an innovative solution that provides the required energy storage while cancelling the net impact on satellite attitude. The concept under investigation relies on a pair of counter-rotating magnetically suspended flywheels. This paper presents an overview of the relevant literature, introduces a preliminary concept, and discusses initial simulation results to illustrate its impact on the attitude dynamics of a small LEO satellite.