Possible applications of spinning tethered systems for Earth and Moon observation: an overview

Tether technology has been proposed for various space applications over the years. Recently, its most common uses include debris removal and the construction of large structures in space without significantly increasing launch mass and volume. Among the others, spinning tethered systems represent a particularly promising solution for advancement in the field of astronomical and planetary observation by enhancing performance compared to the current solutions and enabling new scientific discoveries. Conceptually, these systems consist of multiple satellites connected by a tether in a chain configuration, spinning around the center of mass of the system. These systems can adjust rotation velocity and satellite spacing by reeling the tether in or out, by leveraging the conservation of angular momentum. This enables stable, precise formations at large distances without continuous propellant use. Their versatility also allows spin parameters to be tuned during both mission planning and in orbit, with minimal impact on system design. This paper presents a feasibility study on the use of a CubeSat-scale spinning tethered system for collecting valuable data in the monitoring and observation of Earth and Moon surfaces.