Cubesat science mission proposal and communications subsystem demonstrator

This Master Thesis (MT) is developed under the European Space Astronomy Centre (ESAC) 2017 Trainee Project program. Among 26 projects offered in 2017, the author of this MT was selected for the project nº 20 named: “CubeSat: Science Mission Proposal and Communications subsystem demonstrator”.This Master Thesis is performed under the 2017 ESAC Trainee Project program which covers the development of a low-budget VHF-UHF automated ground station intended for CubeSat satellite operation. While this type of ground station is widely in the radio amateur world for its easy implementation, this ground station introduces the recently growing "software-defined radio" (SDR) technology used as its main transceiver, the most important part of any ground station. Being a very different approach comparing to conventional analog radio transceivers, the implementation of SDR for high power applications implies several difficulties that this project mostly overcomes by the analysis of available RF components in the market, the purchasing of suitable devices, assembling and finally testing for compliance with the requirements stated in the first section of this thesis. In parallel as a secondary objective, a CubeSat telecommunications system demonstrator is developed with the aim of emulating a CubeSat satellite to use for testing purposes along with the ground station to understand the different modulation schemes used in the space sector and the capabilities that SDR technology introduces. This thesis combines the fields of aerospace and telecommunications on a fully basis providing a functional ground station in both VHF and UHF frequency bands, including reception and transmission of narrow and wideband signals, fully documented, characterized, calibrated and integrated into a visually attractive rack enclosure, including the study and recommendations for suitable future improvements and upgrades to the ground station, such as the addition of L-band and S-band capabilities