Robotic exploration of lunar caves: concept analysis of the communication system for an ESA Moon mission

In 2009 a large hole was discovered at Marius Hills, a set of volcanic domes in Oceanus Procellarum, a wide mare at the western edge of the Moon nearside. The hole is believed to be the skylight to an intact lava tube. Recent studies demonstrated that such caverns could be ideal locations for hosting future human bases. The European Space Agency opened a campaign in 2019 through its Open Space Innovation Platform seeking innovative ideas for exploring lunar caves. The thesis work has been developed in collaboration with the small satellites company Alén Space S.L. that formed a consortium with the universities of Vigo and Oviedo to take part in the campaign. The main purpose was to analyse alternative solutions for the communication system architecture and to develop parametric tools for preliminary sizing. A contribution to the advancement of the concept in the framework of the telerobotic operations has also been developed. The latter has been employed as a baseline for the estimation of the data rate of the rovers that will explore the cave. The communication system has been divided in three segments. Budgets for Moon-Earth ground stations links have been developed together with a study regarding the feasibility of the communication exploiting data relay satellites. The second branch of the system regards a wired connection between the surface unit and an interface module entering the cave. A trade-off study on alternative technologies has been carried out. The last part concerns the communication between the rovers exploring the cave and the interface unit. The possibility to exploit IEEE 802.11 standards has been investigated. Differences between the standards and their consequences in terms of system performances and requirements have been analysed accounting also for the multipath characteristics of the cave environment. The outcome of the study reveals that the whole link is feasible exploiting a combination of existing and under development technologies.