Mechanical design for satellite quantum communication, Mechanical design of 3U CubeSat

Luís Pedro Ramalho Barbosa

Key information

Authors:

Luís Pedro Ramalho Barbosa (Luís Barbosa)

Supervisors:

Emmanuel Zambrini Cruzeiro (Emmanuel Zambrini Cruzeiro); Luís Alberto Gonçalves de Sousa (Luís Alberto Gonçalves de Sousa)

Published in

12/05/2023

Abstract

In the current era of increasing CubeSat space launches, traditional communication systems that rely on radio frequency are becoming inadequate for transmitting large amounts of data securely and quickly. Quantum communications systems offer a much more capable, faster, and secure way of transferring data cost-effectively. The primary objective of this thesis is to design a 3U CubeSat and evaluate the feasibility of using commercial off-the-shelf components in a 3U CubeSat structure for a quantum communication downlink experiment between space and Earth. The quantum communication system is developed and provided by the QuLab of Instituto de Telecomunicações - Lisboa. The CubeSat's preliminary design has been created and analysed with a specific focus on the structural design. The integrity and stability of the CubeSat during launch have been evaluated, and multiple parts have been designed to fit the quantum communication optical system. The precise alignment of the dichroic mirrors and lasers is crucial for the system's successful operation. Furthermore, Finite Element Analysis tools have been utilized to conduct stress, modal, and random vibration analyses to determine the mechanical behaviour of the CubeSat and identify potential weak spots. The preliminary design has successfully passed the static analysis loading, with all stresses being below the materials' yield stress. The modal analysis predicted a first resonance frequency of 283,66 Hz, which is above the minimum required by the launching entity of 115 Hz. The random vibration analysis was conducted only for the Z-axis, and the maximum stress obtained was well below the material’s yield strength.