• electrochromic
• femtosatellite
• linear
• mission
• sail

A deep bibliographic research on current femtosatellites layouts has led to a spacecraft design suitable for solar sailing purposes. A Smart Dust equipped with an ElectroChromic System (ECS) concept has been proposed as candidate satellite for heliocentric mission scenarios. In this context, the aim of the current work consists of demonstrating that an ECS-based femtosatellite, after having moved away from the deployer, is able to approach again the chief for sending the collected data. A Smart Dust has a characteristic side length and a small weight that allows the generation of a propulsive thrust by exploiting the solar radiation pressure. The electrochromic coating applied on the Smart Dust surface exposed to the sunlight is used to vary the sail attitude following a proper control law. No relevant works on the Smart Dust attitude control proposed in this work are currently available in specific literature, so the collected results could constitute the basis for an innovative way to exploit the opportunities offered by an ECS-based femtosatellite. A mathematical model has been developed and implemented on MATLAB software, in order to determine the relative motion of a Smart Dust with respect to a chief satellite covering a heliocentric circular orbit both in a linearised and a non-linearised form. The preliminary analysis of the mission scenario treated in this work has highlighted that the analytical results of the linearised model are often not precise. However, if the non-linear model is used, an accurate determination of the relative motion in which the Smart Dust reapproaches the chief spacecraft can be obtained.