Development of a Deployable Orbital Radio assemblY (DORY) for VHF & AIS applications

Current estimates suggest that between 31% and 50% of the global fish production originates from illegal sources, amounting to approximately 11 to 26 million tons of fish per year [1]. This illegal practice of fishing is a strong both ecological and economical hazard. To combat these illegal fishing practices, vessel position signals such as those of the Automatic Identification System (AIS) can be monitored to locate misuse of fish resources. In the context of this work, a preliminary design of a stowable AIS antenna for a cubesat is investigated. The necessary antenna performance is determined with a link budget, with results indicating a required antenna gain GR = 13.28[dBi] at an orbital altitude of h = 600[km]. Both a helical and a dipole design were considered in a preliminary analysis step, with the dipole antenna being chosen as the more suitable candidate. For the mechanical design of the antenna, a coiled tapespring boom was chosen, with four of these booms being stowed in a volume of approximately 0.4U. To inform the mechanical design, parametric studies investigating the influence of material choice on both the structural dynamics of the deployed boom and the deployment dynamics of the stowed boom are carried out. The influence of several geometric tapespring parameters on the boom dynamics was also investigated. Finally, the preliminary mechanical design of the antenna was simulated to check its functional performance, with a maximum antenna gain GR = 2.39 [dBi] and a return loss of approximately S [almost equal to] -15 [dBi] being obtained. These results provide a baseline for future, more detailed investigations of the concept.