Dynamics and control of a sub-CubeSat swarm for distributed beamforming

The emergence of sub-CubeSat spacecraft, such as PocketQubes and ChipSats, enables new possibilities for cost-effective and scalable space missions. Their miniaturisation allows rapid deployment of satellite swarms, facilitating distributed scientific measurements and technological operations which are optimal for swarm missions. Previous research has explored spacecraft swarms and beamforming separately, often assuming fixed satellite configurations and ignoring orbital dynamics, control, and system constraints. No studies have assessed beamforming performance in swarms with relaxed positioning and attitude requirements. This paper presents the first integrated analysis combining a sub-CubeSat satellite platform, swarm mission design, swarm-keeping strategy, and distributed beamforming. The paper also evaluates beamforming performance using a sub-CubeSat-sized platform, highlighting the challenges and advantages of using such miniaturised platforms. First, the low Earth orbit dynamics of a swarm is modelled, including orbital perturbations, and a swarm-keeping strategy using a micropropulsion system is adopted to control the swarm geometry to meet the beamforming requirements. By integrating swarm dynamics and control with beamforming principles, the beamforming performance is evaluated. The paper shows that beamforming is achievable even with the limited capabilities of PocketQubes, by adjusting swarm parameters such as element count, intersatellite spacing, frequency, type of antenna, and antenna pointing, among others.