Swarm system for CubeSats

This paper aims to present an innovative system able to establish an inter-satellite communication crosslink and to determine the mutual physical positioning for CubeSats belonging to a swarm.

Through a system involving a smart antenna array managed by a beamforming control strategy, every CubeSat of the swarm can measure the direction of arrival (DOA) and the distance (range) to estimate the physical position of the received signal. Moreover, during the transmission phase, the smart antenna shapes the beam to establish a reliable and directive communication link with the other spacecraft and/or with the ground station. Furthermore, the authors introduce a deployable structure fully developed at Politecnico di Torino that is able to increase the external surface of CubeSats: this surface allows to gain the interspace between elements of the smart antenna.

As a consequence, the communication crosslink, the directivity and the detection performance of the DOA system in terms of directivity and accuracy are improved.

Moreover, the deployable structure offers a greater usable surface, so a larger number of solar panels can be used. This guarantees up to 25 W of average power supply for the on-board systems and for transmission on a one-unit (1U) CubeSat (10 × 10 × 10 cm).

This paper describes the physical implementation of the antenna array system on a 1U CubeSat by using the deployable structure developed. Depending on actuators and ability that every CubeSat disposes, various interaction levels between elements can be achieved, thus making the CubeSat constellation an efficient and valid solution for space missions.