The CubeSat project is an innovative approach to design, manufacture and launch satellites into space, allowing small companies and universities to reach the Low Earth Orbit at a fraction of the cost and complexity of a normal satellite. One of the critical components of a CubeSat is the antenna, fundamental for bidirectional communication with the ground stations. This kind of space structure needs to be folded and deployed once it reaches the orbit, possibly without active actuation that would increase the total weight of the satellite. Moreover, space is a very complicated environment that pushes requirements on materials' performances to its outermost limits: high/low temperature cycles, high vacuum, solar radiation, debris and atomic oxygen are only a few of the challenges that need to be overcome in order for a space structure to survive for the expected service life of five years. In this thesis, the mechanical design of an antenna for this application is studied, focusing on passive deployment mechanisms obtained through 3- and 4-D printing. After trying multiple designs, the final choice is a quadrifilar helical antenna, manufactured with 4D printing and folded through a programming phase allowing for temperature change. In this way, once in orbit and upon heat application, the deployment can happen. Testing was performed to assess the mechanical properties of the design, and the main limitation to the feasibility of such a project is connected to manufacturing and materials palette. This first proof of concept explores the infinite possibilities of 4D Printing, which will lead to innovative approaches for design and manufacturing in the close future.
Il progetto CubeSat ha permesso un approccio innovativo alla progettazione, produzione e lancio in orbita di satelliti prodotti da piccole imprese o università ad un prezzo molto ridotto rispetto a quelli di un satellite tradizionale. Uno dei componenti più importanti di un satellite è l'antenna, fondamentale nelle comunicazioni da/con la base a terra. Questo tipo di strutture spaziali deve poter essere riposto all’interno del satellite e aperto una volta raggiunta l’orbita, preferendo un’attuazione passiva per evitare di aggiungere ulteriore peso ed ingombro. Inoltre, l’ambiente spaziale è uno di quelli più difficili in cui un materiale possa trovarsi a causa di temperature estreme, detriti spaziali, alto vuoto, radiazione solare e altri fattori, che possono portare la vita di servizio a meno di cinque anni (durata media del programma). In questa tesi viene studiato la progettazione meccanica di un’antenna, concentrandosi su meccanismi di attivazione passivi ottenuti tramite stampa 3D e 4D. Dopo aver studiato numerosi design, la scelta finale ricade su di un’antenna ad elica quadrifilare, prodotta tramite stampa 4D e ripiegata attraverso un processo di programmazione grazie ad una variazione di temperatura. In questo modo, una volta che il satellite raggiunge l’orbita l’antenna può essere aperta grazie ad un aumento di temperatura. Per valutare le proprietà del progetto finale sono stati svolti dei test meccanici, anche se la limitazione di questo progetto è risultata essere principalmente legata al processo di produzione e alla scelta di materiali disponibili. Questo studio preliminare apre ad innumerevoli possibilità legate alla stampa 4D che può portare ad approcci innovativi per il design e la produzione nel prossimo futuro.
Active 3D-printed mechanisms for antennas in CubeSats
ALBERIO, GAIA
2017/2018
Abstract
The CubeSat project is an innovative approach to design, manufacture and launch satellites into space, allowing small companies and universities to reach the Low Earth Orbit at a fraction of the cost and complexity of a normal satellite. One of the critical components of a CubeSat is the antenna, fundamental for bidirectional communication with the ground stations. This kind of space structure needs to be folded and deployed once it reaches the orbit, possibly without active actuation that would increase the total weight of the satellite. Moreover, space is a very complicated environment that pushes requirements on materials' performances to its outermost limits: high/low temperature cycles, high vacuum, solar radiation, debris and atomic oxygen are only a few of the challenges that need to be overcome in order for a space structure to survive for the expected service life of five years. In this thesis, the mechanical design of an antenna for this application is studied, focusing on passive deployment mechanisms obtained through 3- and 4-D printing. After trying multiple designs, the final choice is a quadrifilar helical antenna, manufactured with 4D printing and folded through a programming phase allowing for temperature change. In this way, once in orbit and upon heat application, the deployment can happen. Testing was performed to assess the mechanical properties of the design, and the main limitation to the feasibility of such a project is connected to manufacturing and materials palette. This first proof of concept explores the infinite possibilities of 4D Printing, which will lead to innovative approaches for design and manufacturing in the close future.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/147456