Propulsive and mechanical design of a CubeSat mock-up for low-gravity testing

In the last few years, smaller companies and research laboratories are focusing on satellite solutions with reduced dimension, production time and costs to conduct scientific experiments and technological demonstrations in orbit. The advent of small satellites in space missions has changed the standards of the research with a consequent increasing interest in miniaturized systems. In this scenario the most relevant studies currently under way involve micro-propulsion systems, high-throughput telecommunication terminals, guidance algorithms and navigation sensors, capture and servicing technologies. In particular the development of different technologies for proximity operations and docking manoeuvres are under investigation for several applications like on-orbit servicing (OOS), retrieval, i.e. capture and return to ground, of spacecraft and the assembly of large in-space structures (On -Orbit Assembly, OOA). Experimental Rendezvous in Microgravity Environment Study (ERMES) is a technological demonstrator designed to test an autonomous docking manoeuvre between two free-flying CubeSats mock-ups. The experiment has been selected by the European Space Agency (ESA) education office, for the Fly Your Thesis! 2022 (FYT), and performed during the 79th ESA Parabolic Flight Campaign. This thesis presents the design and development of the propulsive and mechanical subsystems of the main ERMES CubeSat mock-up , the Chaser, which is also equipped with Guidance Navigation and Control (GNC) system and miniaturized docking interfaces. The Chaser is the active part, based on 2U CubeSat and propelled by a cold gas propulsive system based on expendable CO2 cartridges. Relevant focus is given to the design of the two subsystems, their implementation, testing and safety management. Moreover a first analysis of the data collected during the campaign is given, and compared with the theoretical results.