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Magnetic attitude control systems are suitable for very small satellites, and yet provide a simple and robust method to detumbling and attitude control. In this work we analyse the use of hard ferromagnetic materials and magnetorquers to control the attitude of a spherical femtosatellite. The model will propagate the orbit of the satellite (disregarding the effects of the atmosphere) by means of SGP4 or SGP8. Once the orbit is propagated, we will use a suitable model of the geomagnetic field (IGRF13 or WMM) to determine the magnetic field in the location of the satellite. Passive ADCS will be obtained by means of the use of hysteresis rods. In order to add some control, a set of magnetorquers will be designed. Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

Ionospheric disturbances induced by seismic activity have been studied in the last years by many authors, showing an impact both before and after the occurrence of earthquakes. In this study, the ionospheric scintillation produced by the 2021 La Palma volcano eruption is analyzed. The "Cumbre Vieja" volcano was active from September 19th to December 13th, 2021, and many magnitude 3–4 earthquakes were recorded, with some of them reaching magnitude 5. In this study the three methods: GNSS reference monitoring, GNSS Reflectometry (GNSS-R) from NASA CYGNSS, and GNSS Radio Occultation (GNSS-RO) from COSMIC and Spire constellations, are used, allowing us to compare and evaluate their performance in the same conditions. To compare the seismic activity with ionospheric scintillation, earthquakes’ generated energy, and percentile 95 % of the intensity scintillation parameter (S4), measurements have been computed every 6 h intervals for the whole duration of the volcanic eruption. GNSS-RO has shown the best correlation between earthquakes’ energy and S4, with values up to 0.09 when the perturbations occur around 18 h after the seismic activity. GNSS reference monitoring stations data also shows some correlation 18 h after and 7–8 days after. As expected, GNSS-R is the one that shows the smallest correlation, as the ionospheric signatures get masked by the signature of the surface where the reflection is taking place. Additionally, as expected as well, the three methods show a smaller correlation during the week before earthquakes. This work was supported in part by the grant PID2021-126436OB-C21 from the Programa Estatal para Impulsar la Investigación Científico-Técnica y su Transferencia, del Plan Estatal de Investigación Científica, Técnica y de Innovación 2021-2023 (Spain) and in part by the European Social Fund (ESF). GNSS-RO Spire data has been provided by the European Space Agency through the ESA TPM SPIRE project id 67176.

Las comunicaciones han evolucionado de manera exponencial, gracias a los avances tecnológicos. Por este motivo, surgen nuevas formas de comunicaciones, una de ellas el IoT. Que consiste en una tecnología que facilita la recopilación de datos y da conectividad a todo tipo de elementos, como por ejemplo los utilizados en las viviendas domóticas. Este proyecto, se centrará en la utilización de un tipo de comunicación IoT, en concreto la comunicación satelital. El objetivo principal del proyecto es el diseño e implementación de la comunicación satelital utilizada en la transmisión de la información desde una boya, situada en la superficie del mar. Para conseguir está transmisión de datos se utilizará un módulo Kinéis, que estará controlado por el microcontrolador ESP32. Para la geolocalización de la boya se usará un GPS y se transmitirán otros datos, además de los obtenidos por el GPS y relacionados con características del medio marino. Estos últimos datos, se almacenarán en la tarjeta de memora para su transmisión. Todos los datos enviados al satélite se monitorizarán en una página web, de manera que pueden ser consultados en cualquier momento. Communications have evolved exponentially, thanks to technological advances. For this reason, new forms of communication are emerging, one of which is the IoT. This is a technology that easy data collection and provides connectivity to all types of elements, such as those used un automation homes. This project will focus on the use of one type of IoT communication, specifically satellite communication. The main purpose of the project is the design and implementation of the satellite communication and the transmission of information from a buoy. To archive this data transmission will be used Kinéis module, which will be controlled by the ESP32 microcontroller. A GPS will be used to geolocate the buoy. On the other hand, other data will be transmitted, apart from these obtained by the GPS, and are related to the characteristic of the marine environment. This last data will be stored on a memory card for transmission. All data sent to the satellite will be monitored on a website, so that this data can be consulted at any time.

Los altos costes que implica la ejecución de cualquier ensayo real relacionado con la investigación en nanosatélites, así como la gran cantidad que recursos tanto humanos como temporales que estos requieren imposibilitan que cualquier institución educativa pueda ofrecer a su alumnado de forma generalizada la posibilidad de formarse en este ámbito. Este hecho ha generado una tendencia por parte de estas instituciones educativas superiores a sustituir el enfoque de enseñanza práctica por uno más orientado a al estudio teórico o la práctica a través de simulaciones computacionales. En este proyecto se lleva a cabo el desarrollo, diseño y fabricación a nivel mecánico y electrónico de un prototipo de pruebas enfocado al estudio tanto de los sistemas de control de actitud de un U1 CubeSat como de nuevas tipologías de placas fotovoltaicas basadas en patrones de Origami. En este prototipo se incluye tanto el diseño de un mecanismo de despliegue de dichas tipologías de placas fotovoltaicas desplegables como el desarrollo e implementación del dispositivo de control de actitud en el cual se incorpora dicho mecanismo. El desarrollo de este dispositivo también engloba una notable mejora en los subsistemas de medición, así como en el algoritmo de control de posición. El diseño tanto del bastidor del prototipo del U1 CubeSat como de los sistemas de control de actitud y el mecanismo de despliegue de placas fotovoltaicas es modular. Esto implica que cada uno de estos subsistemas puede funcionar de forma independiente al resto, lo que facilita en gran medida el estudio independiente de cada uno ellos y encaja a la perfección con la ideología de los CubeSats modulares, los cuales pueden variar sus funcionalidades dependiendo de los elementos añadidos. The high costs involved in carrying out any real test related to nano-satellite research, as well as the large amount of human and temporary resources that these requires, make it impossible for any educational institution to offer its students the possibility to be formed in this area. This fact has generated a tendency for these educational institutions to replace the practical teaching on this field by a more theoretical approach only practiced through computational simulations. However, this project carries out the development, design, and manufacture, at both mechanical and electronic level, of a test prototype focused on the study of the attitude control systems of a U1 CubeSat, as well as the new typologies of photovoltaic panels based on Origami patterns. This prototype includes both the design of an unfolding mechanism for these types of deployable photovoltaic panels, and the development and implementation of the attitude control device in which the mechanism is incorporated. Moreover, this project also covers notable improvements of both the measurement subsystems and the position control algorithm. The proposed design of the U1 CubeSat prototype frame, the attitude control systems and the photovoltaic panel deployment mechanism is modular. This implies that each of these subsystems can be operated independently from the rest, which greatly eases the study of each one of them and fits perfectly with the ideology of modular CubeSats, which can improve their functionalities depending on the added elements. Considering so, this prototype incorporates an attitude control device with a single reaction wheel and its corresponding MPU position sensor, as well as a mechanism for deploying photovoltaic panels based on Origami patterns. It should be noted that each of these systems includes its corresponding power supply, all controlled by an STM32 BluePill microcontroller and communicated through an HC-06 Bluetooth module.

This work contains the analysis and improvements regarding attitude nanosatellite testing procedures. An utterly new system for measuring angular velocities has been designed from scratch in order to be applied to Cubesat testing campaigns. This system will help to track the rotations of the nanosatellite in the different tests. Knowing the angular velocity of the nanosatellite while performing the tests is so important. It allows to calibrate the gyroscopes as well as set a perfect and knows conditions to the satellite. Also, the measurements can be compared with the gyroscope angular velocityes obtained in order to recalibrate the system if necesary. Furthermore, a new design for Helmholtz coils software has been proposed using a user Interface in C++. This new software allows the user to initialize the coils with the desired magnetic fields required for testing. Two main operating ways has been considered: Static and Dynamic orbit magnetic field generation. Both systems can work altogether in order to check the attitude determination and control of the nanosatellite during testing campaigns. Nanosatellite needs to perform testing before its launch. Thus, the whole project avoids expensive risks which could doom the mission. The results obtained in this work show that the angular tracking works as desired for the testing purposes and the Helmholtz coils GUI simplifies a lot the testing process from the user point of view. Aquest treball conté l’anàlisi i les millores pel que fa als procediments de prova de nano satèl·lits d’actitud. Un sistema completament nou per mesurar velocitats angulars ha sigut dissenyat des de zero per aplicar-lo a les campanyes de proves de Cubesat. Aquest sis- tema ajudarà a seguir les rotacions del nano satel·lit en les diferents proves. Con `eixer la velocitat angular del nano satel·lit mentre es realitzen les proves és molt important, ja que permet calibrar els giroscopis així com establir unes condicions perfectes i conegudes al satèl·lit.

Modern satellites deployed in low Earth orbit (LEO) accommodate processing payloads that can be exploited for edge computing. Furthermore, by implementing inter-satellite links, the LEO satellites in a constellation can route the data end-to-end (E2E). These capabilities can be exploited to greatly improve the current store-and-forward approaches in Earth surveillance systems. However, they give rise to an NP-hard problem of joint communication and edge computing resource management (RM). In this paper, we propose an algorithm that allows the satellites to select between computing the tasks at the edge or at a cloud server and to allocate an adequate power for communication. The overall objective is to minimize the energy consumption at the satellites while fulfilling specific service E2E latency constraints for the computing tasks. Experimental results show that our algorithm achieves energy savings of up to 18% when compared to the selected benchmarks with either 1) fixed edge computing decisions or 2) maximum power allocation., Accepted in ICC Workshops 2022

During last years, space missions have evolved from monolithic spacecrafts architectures, to distributed ones, which are known as Distribute Satellite Systems (DSS). This spacecraft architecture has changed the space paradigm, as it has appeared the need of establishing communications between satellites to achieve the mission objectives. Despite this the need of simulating and emulating the communications between satellites, none of the available tools have complete inter-satellite communications capabilities. This final degree thesis presents contributions to the already existing simulator developed by NanoSat Lab. The contributions consist in the implementation of the Electric Power Supply (EPS) subsystem. Moreover, this thesis also contributes to the development of a Satellite Contact Emulator, developed by i2Cat, focusing on the development of the central PC that orchestrates the emulation. Recentment, les missions espacials han evolucionat d'una arquitectura basada en un sol satèl·lit, a una arquitectura distribuïda. Aquest tipus d'arquitectura és coneguda com a Distribute Satellite Systems" (DSS). L'aparició d'aquesta nova estructura ha provocat un canvi en el paradigma de l'espai, ja que ha sorgit la necessitat d'establir comunicació entre els satèl·lits per assolir els objectiu marcats de les missions. Tot i haver la necessitat d'emular i simular les comunicacions enter satèl·lits, cap de les eines actuals té suficients funcionalitats implementades per assolir aquesta emulació i simulació. Aquest treball de fi de grau presenta les contribucions fetes a un simulador ja existent, el qual ha estat desenvolupat pel NanoSat Lab de la UPC. La contribució feta consisteix en la implementació d'un subsistema que modeli una EPS. A més a més, aquest treball de fi de grau també contribueix en el desenvolupament d'un Satellite Contact Emulator, el qual ha estat desenvolupat per i2Cat. En aquesta contribució es farà menció especial en l'ordinador central que executa l'emulació. Recientemente, las misiones espaciales han evolucionado de una arquitectura basada en un solo satélite, a una arquitectura distribuida. Este tipo de arquitectura es conocida como Distribute Satellite Systems" (DSS). La aparición de esta nueva estructura ha provocado un cambio en el paradigma espacial, ya que ha surgido la necesidad de establecer comunicación entre los satélites para conseguir los objetivos de las misiones. Aunque exista la necesidad de emular y simular las comunicaciones entre satélites, ninguna de las actuales herramientas tiene las funcionalidades suficientes para conseguir dicha emulación y simulación. Este trabajo de fin de grado presenta las contribuciones hechas a un simulador ya existente, el cual ha sido desarrollado por el NanoSat Lab de la UPC. La contribución hecha consiste en la implementación de un subsistema que modela una EPS. Además, este trabajo de fin de grado también contribuye al desarrollo de un Satellite Contact Emulator, el cual ha sido desarrollado por i2Cat. Esta contribución pone un énfasis especial en el ordenador central que ejecuta la emulación.

La calidad del aire preocupa en muchas zonas urbanas y áreas industriales alrededor del mundo, y particularmente en la región europea, donde en 2019 casi 20 países superaron los valores de dióxido de nitrógeno NO2 límite impuestos por la Directiva de la Comisión Europea. Este estudio propone un análisis comparativo del impacto de los principales GEI entre 2019-2022. Los resultados destacarán sobre todo la dinámica de la contaminación por NO2 sobre la abrupta situación provocada por el brote de COVID-19, caracterizada por un disminución brusca de las intensidades del tráfico y las actividades industriales. Con ello surgen estas cuestiones: ¿Es la contaminación del aire exclusiva de zonas urbanas con grandes superficies industriales? ¿El confinamiento por COVID-19 ha propiciado cambios notables en las emisiones troposféricas? ¿Es el NO2 el gas más contribuyente al efecto invernadero? ¿Existe alguna relación entre las emisiones de NO2 y cambios en algún indicador de actividad económica? La qualitat de l'aire preocupa a moltes zones urbanes i àrees industrials al voltant del món, i en particular a la regió europea, on en 2019 casi 20 països superen els valors de diòxid de nitrógeno NO2 límits impostos per la Directiva de la Comissió Europea. Aquest estudi proposa un anàlisi comparatiu de l'impacte dels principals GEI entre 2019-2022. Els resultats destacaran sobre tota la dinámica de la contaminació per NO2 sobre la situació brusca provocada pel brot de COVID-19, caracteritzada per una disminució brusca de les intensitats del trànsit i les activitats industrials. Amb ell surgen aquestes preguntes: ¿És la contaminació de l'aire exclusiva de zones urbanes amb grans superfícies industrials? El confinament per COVID-19 ha propiciat canvis notables a les emissions troposfèriques? ¿És el NO2 el gas més contribuint a l'efecte hivernacle? ¿Existe alguna relació entre les emissions de NO2 i els canvis en algun indicador d'activitat econòmica? Air quality is a concern in many urban and industrial areas around the world, and particularly in the European region, where in 2019 almost 20 countries exceeded the NO2 nitrogen dioxide limit values imposed by the European Commission Directive. This study proposes a comparative analysis of the impact of the main GHGs between 2019-2022. The results will highlight in particular the dynamics of NO2 pollution on the abrupt situation caused by the COVID-19 outbreak, characterized by a sharp decrease in traffic intensities and industrial activities. This raises the following questions: Is air pollution exclusive to urban areas with large industrial areas? Has COVID-19 confinement led to significant changes in tropospheric emissions? Is NO2 the most greenhouse gas contributor? Is there a relationship between NO2 emissions and changes in any indicator of economic activity?

The project developed in this thesis consists of creating a PocketQube payload in charge of monitoring the 24 to 25 GHz band to enforce that the emissions of the 5G communications band are within limit. In this thesis, the design of the main RF circuit has been carried out. It has been divided in different sub-systems, for each of which, a PCB has been created to be able to test and characterize them. From those tests, information has been taken and was used to design the low frequency circuit, which includes the power supply and the inputs and outputs interface of the main RF circuit. El proyecto desarrollado en este trabajo de fin de grado consiste en la creación de una carga útil de un PocketQube destinada a monitorizar la banda de los 24 a los 25 GHz con tal de controlar que las emisiones de la banda de comunicaciones de 5G se encuentran dentro de los límites. En este trabajo de fin de grado, se ha realizado el diseño del circuito principal de RF. Éste ha sido dividido en diferentes sub-sistemas, para cada uno de los cuales, una PCB ha sido creada para testearlos y caracterizarlos. De estos tests, información ha sido extraída y usada para diseñar el circuito de baja frecuencia, el cual incluye la alimentación y la interfaz de entradas y salidas del circuito de RF principal. El projecte desenvolupat en aquesta treball de fi de grau consisteix en crear una càrrega útil per a un PocketQube encarregada de monitorar la banda dels 24 als 25 GHz per a controlar que les emissions de la banda de comunicació de 5G es troben dins dels límits. En aquest treball de fi de grau, s’ha portat a terme el disseny del circuit principal de RF. Aquest ha estat dividit en diferents sub-sistemes, per a cadascun d’aquests, s’ha creat una PCB per a poder testejar-los i caracteritzar-los. D’aquests tests, s’ha extret informació que s’ha utilitzat per dissenyar el circuit de baixa freqüència, que inclou l’alimentació i la interfície de les entrades i sortides del circuit principal.

La humedad del suelo es una variable muy importante en el sistema climático y en el medio ambiente, ya que es clave en el intercambio de agua y energia entre la superfície de la Tierra y la atmósfera. Actualmente, la misión Soil Moisture and Ocean Salinity (SMOS), la misión de la Agencia Espacial Europea (ESA), utiliza un radiómetro que trabaja en banda L para obtener mapas de la humedad del suelo en todo el mundo. Desde que el satélite está en òrbita, se ha intentado mejorar la resolución espacial de los mapes para obtener aplicaciones a nivel regional y local, como la detección de zonas inundables y el riesgo de incendio. Este proyecto consiste en el desarrollo de un algoritmo para mejorar la resolución espacial de los mapas de humedad del suelo hasta 20 metros utilizando cuatro variables: la humedad del suelo a 25 km (baja resolución), las temperaturas de brillo en las dos polarizaciones (horitzontal y vertical) a 25 km, la temperatura superficial terrestre (LST) y el índice de vegetación de diferencia normalizada (NDVI). Este último se ha obtenido de las medidas de Sentinel 2 a 20m de resolución espacial. Una vez obtenidos los mapas, se ha realizado un estudio de las medidas obtenidas y se han comparado con datos in-situ de una zona concreta de la Península Ibérica que incorpora sensores que miden la humedad del suelo diariamente, llamada zona REMEDHUS (Red de Estaciones de Medición de Humedad del Suelo de la Universidad de Salamanca), con el fin de analitzar la validez de los resultados. La humitat del sòl és una variable molt important tant en el sistema climàtic com en el medi ambient ja que és clau en l'intercanvi d'aigua i energia entre la superfície de la Terra i l'atmosfera. Actualment, la missió Soil Moisture and Ocean Salinity (SMOS), de l'Agència Espacial Europea (ESA), utilitza un radiòmetre que treballa en banda L per tal d'obtenir mapes de la humitat del sòl arreu del món. Des de que el satèl·lit està en òrbita, s'ha intentat millorar la resolució espacial dels mapes per tal d'obtenir aplicacions a escala regional i local, com la detecció de zones inundables i el risc d'incendi. Aquest projecte consisteix en el desenvolupament dun algoritme per tal de millorar la resolució dels mapes d'humitat del sòl fins a 20 metres tenint en compte quatre variables: la humitat del sòl a 25 km (baixa resolució), les temperatures de brillantor en les dues polaritzacions (horitzontal i vertical) a 25 km, la temperatura superficial terrestre (LST) i l'índex de vegetació de diferència normalitzada (NDVI). Aquest últim paràmetre s'ha obtingut de les mesures Sentinel 2 a 20 metres de resolució espacial. Un cop obtinguts els mapes, s'ha realitzat un estudi de les mesures obtingudes i s'han comparat amb dades in-situ d'una zona concreta de la Península Ibèrica que presenta sensors que mesuren la humitat del sòl de forma diària, anomenada zona REMEDHUS (Red de Estaciones de Medición de Humedad del Suelo de la Universidad de Salamanca), per tal d'analitzar la validesa dels resultats. Soil moisture is an important variable in both the climate system and the environment as it is based on the exchange of water and energy between the Earth's surface and the atmosphere. Currently, the European Space Agency (ESA)'s Soil Moisture and Ocean Salinity (SMOS) is a mission which uses a L-band radiometer to obtain soil moisture and ocean salinity globally and with a revisit time on the Equator of three days. Since the satellite is in orbit, many studies have been done to increase the spatial resolution of the soil moisture maps to obtain regional-scale applications, such as detection of flood zones and fire risk. This project consists on the development of an algorithm to increase the resolution of soil moisture maps up to 20 meters taking into account four variables: soil moisture at 25 km (low resolution), horizontal and vertical brightness temperatures at 25 km, land surface temperature (LST) and the normalized difference vegetation index (NDVI). This last parameter is obtained from the Sentinel 2 measurements at 20m of spatial resolution. Once the maps were obtained, a study of the measurements have been carried out and compared with in-situ data from a specific area of the Iberian Peninsula which has sensors that measure soil moisture daily, called REMEDHUS (Red de Estaciones de Medición de Humedad del Suelo de la Universidad de Salamanca), in order to analyse the validity of the results.

Traditional satellite communications missions are based on artificial satellites that can communicate with ground stations. This type of network provides wide-area coverage as well as resilient communications. Satellite systems are expected to be merged with the introduction of 5G/6G mobile systems to offer seamless connection and ubiquitous coverage for users worldwide. SDN/NFV are two of the most important enabling technologies for deploying new 5G/6G mobile network architectures, and they are widely used in telecommunications to deliver different services. Its method is based on network softwarization, which abstracts the physical infrastructure by separating the functionality of the hardware. Furthermore, using SDN, it is possible to reconfigure the network in flexible topologies that adapt to the performance necessary at any given time, thereby maximizing resources and lowering costs. SDN/NFV, on the other hand, relies on a strong and continuous network layer to construct a control plane and deploy VNF. However, establishing a stable link is difficult in constellations of several LEO/MEO satellites. TALENT is a software platform created with the purpose of supplying satellite and ground connection by coordinating satellite and terrestrial systems from a single location, developed under the SaTG5 project that defined the integration of satellite solutions for 5G. Regardless of these solutions, a robust testbed is required to help in the discovery of novel protocols for delivering and orchestrating network services over satellite networks that take dynamic network architecture on satellite constellations into account. This thesis addresses the lack of a testbed for deploying VNF via a satellite network, as well as the orchestration and deployment of VNF across various satellite constellations. Its main contribution is an update to TALENT to allow it to work with newer Open Source MANO versions, and a testbed for deploying a VNF across a simulated satellite network based on the OpenSand satellite simulation tool. Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

In this report, we will explore the way to measure the angular position of a satellite, more precisely of a CubeSat, expressed with the Euler angles. We therefore consider all the rotations that are possible in a three-dimensional space. The measurements will be made via an image processing algorithm, using MatLab. The CubeSat is a relatively new technology, it is a small satellite, most of the time cubic and about 10 cm on each side. The CubeSats, as in our case, are used in the framework of educational projects, because of their convenient size. There are already internal devices that allow to know the attitude of the CubeSat. Thus, the final goal of these measurements is an external control, in order to verify the correct measurement of the CubeSat instruments. Dans ce rapport, nous allons explorer la manière de mesurer la position angulaire d’un satellite, plus précisément d’un CubeSat, exprimé avec les angles d’Euler. Nous considérons ainsi toutes les rotations réalisables dans un espace tridimensionnel. Les mesures seront réalisés via un algorithme de traitement d’images, sous MatLab. Les CubeSat sont une technologie récente, il s’agit d’un petit satellite, souvent de forme cubique, généralement de 10 cm de côté. Les CubeSat, comme dans notre cas, sont utilisés dans le cadre de projets pédagogiques, au vu de leur taille pratique. Il existe déjà des dispositifs internes qui permettent de connaître l’orientation d’un satellite. Ainsi, le but final de ces mesures est un contrôle externe, afin de vérifier la bonne mesure des instruments du CubeSat. Incoming

Aquest ítem conté el treball original, defensat públicament, així com una versió millorada del mateix amb modificacions menors, autoritzada per l'escola The Earth observation industry has undergone a substantial transformation in the last decade. Until recently, Earth observation systems for the most critical commercial and institutional needs were mainly dedicated assets owned and operated by governments or big corporations, often at national level. Recent evolutions like the emergence of private investment and the development of appreciably cheaper instrumentation, systems and technologies in the field, such as the rise of CubeSats and SpaceX reusable launch rocket systems have disrupted the status quo into a new paradigm, labelled New Space. A possible further disruption into this new paradigm is the advent of High-Altitude Platform Systems (HAPS), also called Pseudo-Satellites. These systems feature unbeatable performance advantages in resolution and persistence at local observation against satellites. Nevertheless, no pseudo-satellite has yet been fully implemented, with a history of test failures and program funding terminations. This thesis explores the reasons for the technical lack of success of these initiatives (particularly an aeroelastic phenomenon called flutter) as well as reviews the necessary technologies needed for these systems to work, with a compilation of the past attempts through the scientific literature available. Finally, with a thorough examination of the economic and technological state of the art of the Earth observation industry and its applications, the study discusses the conditions under which the implementation of HAPS by an Earth observation company could be beneficial, making use of Alex Osterwalder's business model canvas methodology. Analysis demonstrates that HAPS companies could have the potential to disrupt the Earth observation industry through the implementation of videographic recording and real-time change monitoring, posing an attractive business case opportunity either for existing Earth observation companies or new entrants. So far, the constructors that have developed this technology the farthest are Thales Alenia Space with their aerostat system StratobusT'-1, as well as Airbus with their Zephyrnr UAV. Further research such a .. c.; financial budgeting and experimental results to prove client adoption should be carried out for companies interested in implementing these solutions.

WUSAT-3 is a 3U CubeSat being designed to carry an experimental RF signal direction finding payload in Low Earth Orbit (LEO). Successful outcome of this experiment could lead to significant benefits for the field of wildlife monitoring from Space. Commercial adoption of this process would enable the development and use of much smaller, lighter RF tracking tags, which in turn would considerably increase the potential range of species that could be tracked by Satellites. The effect of the Covid-19 pandemic lockdowns has limited physical progress over the past 18 months, but the team continues to gain enormous experience and motivation from pursuing this exciting project with a very real-world mission. A recent return to near-normal working patterns has enabled the team to fully engage with the practicalities of progressing the previously produced WUSAT-3 Configuration Model, towards a testable Engineering Model. This paper outlines the development of both the initial chassis prototype (including mechanisms) and a subsystem FlatSat as a first stage towards building the complete Engineering Model. The chassis prototype was required to meet all the requirements of the FYS Design Specification [1], the NanoRacks CubeSat ICD [2], the CubeSat Design Specification [3] and those features identified by the outcomes of the WUSAT-3 Configuration Model. The FlatSat was required to include all subsystems capable of being constructed and tested without the availability of certain proprietary items that will be purchased later. The function and interface of these items, where it was necessary for the purpose of testing the assembled subsystem units that were available, was met by the design and inclusion of temporary substitute arrangements that provided similar performance. Systems Engineering methodologies were employed throughout as a means of ensuring that the design features of both chassis and FlatSat met all necessary requirements

Two universities joined forces to develop a shared ground segment (Ground Stations and Mission Operation Centers) for satellite signals reception, capable of working together autonomously in a network to receive telemetry data and decode information. The main objective of this cooperation and network is to, firstly, give both universities an infrastructure capable of receiving signals in VHF and UHF. Secondly, and most importantly, it aims to create an exchange of experiences between students from these universities while also contributing to the regional development of each country in nanosatellite data reception technology. The ground segment itself provides mutual data collection on a private server, using two ground stations located in different hemispheres to expand global coverage and minimize revisit time, which also contributes to supplying the nanosatellite telemetries database, which is being built in Portugal. The server architecture allows both universities to schedule future passes of their chosen satellites, recording them in a log file that can be used in future studies, enabling research groups to gain experience in signal processing analysis. The modular system is developed entirely using Commercial Of-The-Shelf (COTS) components and 3D printed parts, including Antennas, Amplifiers, Filters and also SDRs (Software Defined Radio), leaving the door open to new integrations that can expand frequency coverage, or system performance improvements. The design supports a wide variety of missions, operating on amateur radio frequency in VHF (2 m band of 144-146 MHz) and UHF (70 cm band of 430-440 MHz), enabling remote access and remote control of the antennas and their recorded data. All the ground segment architecture, hardware, and software, as well as its operational procedures, are discussed in this paper and can be found in detail on our public repository in GitLab. As of March 21st, it has completed several observations for verification. The results are being processed on a low-cost computer (Raspberry Pi4) connected to an SDR which in turn connects to the antennas. The assembly of this interface intends to give a friendly user experience and, if desirable, an easy expansion of this system. The project developed can be easily replicated in other locations around the world, mainly because of its low price and ease of use.

Cohesive Distributed Satellite Systems (CDSSs) is a key enabling technology for the future of remote sensing and communication missions. However, they have to meet strict synchronization requirements before their use is generalized. When clock or local oscillator signals are generated locally at each of the distributed nodes, achieving exact synchronization in absolute phase, frequency, and time is a complex problem. In addition, satellite systems have significant resource constraints, especially for small satellites, which are envisioned to be part of the future CDSSs. Thus, the development of precise, robust, and resource-efficient synchronization techniques is essential for the advancement of future CDSSs. In this context, this survey aims to summarize and categorize the most relevant results on synchronization techniques for Distributed Satellite Systems (DSSs). First, some important architecture and system concepts are defined. Then, the synchronization methods reported in the literature are reviewed and categorized. This article also provides an extensive list of applications and examples of synchronization techniques for DSSs in addition to the most significant advances in other operations closely related to synchronization, such as inter-satellite ranging and relative position. The survey also provides a discussion on emerging data-driven synchronization techniques based on Machine Learning (ML). Finally, a compilation of current research activities and potential research topics is proposed, identifying problems and open challenges that can be useful for researchers in the field.

The Educational Irish Research Satellite (EIRSAT-1) is a 2U CubeSat being designed, built and tested at University College Dublin. A FlatSat platform known as EIRFLAT-1 has been constructed to enable the testing and development of the CubeSat. EIRFLAT-1 facilitates the electrical connections between CubeSat components while leaving key interfaces accessible for test equipment and allowing for the hot swapping of components. Commercial Off The Shelf and in-house developed hardware has been tested using EIRFLAT-1 at component, subsystem and full system level. In addition, the FlatSat has been used for flight software development. This paper describes the design of EIRFLAT-1 including electrical and mechanical components and additional ground support equipment developed to assist in the testing and development activities. EIRFLAT-1 has proven to be an invaluable tool for testing and has led to the discovery of issues and unexpected behaviour with flight hardware which would have contributed to schedule delays if undiscovered until after the satellite was assembled. Moreover, EIRFLAT-1 facilitated early and incremental testing of both software and operations procedures. The schematics for the electrical design of EIRFLAT-1, which is compatible with all CubeSat Kit PC/104 components, has been made publicly available for use by other educational CubeSat teams

Student Satellite program at TalTech, Tallinn University of Technology, Tallinn, Estonia was initiated in 2014 with an aim to impart space technology knowledge to the Estonian students as well as assist towards development of new Space Technologies in Estonia. Two 1-Unit CubeSat named Koit and Hämarik that translates respectively as Dawn and Twilight in Estonian are part of the TalTech Satellite Program. The main scientific mission of the CubeSats was to demonstrate Earth observation and Optical Communication technology. Satellites had two types of cameras, an RGB Camera and an NIR Camera to carry out Earth Observation over Estonia. Testing High Speed Optical communication technology from LEO (Low Earth Orbit) was the second major scientific goal and for this purpose the CubeSats had LED (Light Emitting Diode). Koit CubeSat was successfully launched to space on-board Soyuz rocket on July 5, 2019 and Hämarik CubeSat was launched to Space on September 3, 2020 on-board Arianespace Vega Rocket. Koit CubeSat did not contact the Ground station for more than a year since its launch and it was assumed to be lost but on November 21, 2020 it made the first contact with the Ground Station. Hämarik CubeSat was first contacted on November 15, 2020. The team has been successful in updating software of Hämarik and further work is being done on the software with broader functions. Optical communication has not been tested yet because ground station for optical communication has not been developed yet but a good achievement in the path to optical communication was to see the satellites with small hobby telescope and one of the satellite team member was successful to detect the Hämarik CubeSat on 17 August 2021 which was at a distance of about 792 Kilometres. Satellite team is in contact with the Hämarik and has been successful to download a few thumbnails and is working to establish a quick data connection with it and determine its exact position so that the cameras can be focused towards the Earth in order to get the whole images captured by the CubeSat.

Thermal knife HDRMs (Hold Down and Release Mechanisms) are commonly used in CubeSats and other small satellites. However, detailed information on proven designs is difficult to find. Design of a robust and reliable mechanism can present technical challenges which may only become apparent during testing, and often only when tested in a space representative environment. A custom thermal knife HDRM was designed and built for the antenna deployment module of EIRSAT-1 to deploy four coil spring antenna elements, but the same or a similar design could be repurposed quite easily to release a wide range of CubeSat deployables. In this design resistors are used to cut dyneema lines. For robustness and reliability, the thermal response of the mechanism must be well understood. To reach the melting point of the dyneema (150C) the power dissipated in the resistors must often exceed the maximum rated value. Therefore, choosing the operating current and the burn time is a careful trade-off between ensuring that the resistor reliably cuts the dyneema line and ensuring that the resistor, solder joints, PCB and nearby components are not damaged by the high temperatures. These choices are further complicated by the requirement that the mechanism operates over a range of temperatures. A thermal vacuum test campaign was carried out to better understand and characterise the thermal behaviour of the EIRSAT-1 mechanism. For the test a model of the mechanism was built with several temperature sensors installed. Two of these sensors were installed directly on the body of the resistors using a thermally conductive epoxy. Burn tests were performed in vacuum at temperatures between -37C and +56C. The test shows many interesting results including the effect of the dyneema lines on the thermal response, the possibility of desoldering the burn resistors and a comparison between the performance at ambient and vacuum conditions. Finally, a summary is given of the key technical challenges associated with this type of mechanism along with some recommendations to help make future designs more robust and reliable.

The Remote sensing and Interference detector with radiomeTry and vegetation Analysis (RITA) is one of the Remote Sensing payloads selected as winners of the 2nd GRSS Student Grand Challenge in 2019, to fly on board of the 3U AlainSat-1. This CubeSat is being developed by the National Space Science and Technology Center (NSSTC), United Arab Emirates University. RITA has been designed as an academic mission, which brings together students from different backgrounds in a joint effort to apply very distinct sensors in an Earth Observation mission, fusing their results to obtain higher-accuracy measurements. The main payload used in RITA is a Total Power Radiometer such as the one on board the FSSCat mission. With these radiometric measurements, soil moisture and ice thickness will be obtained. To better characterize the extensive Radio-Frequency Interferences received by EO satellites in protected bands, several RFI Detection and Classification algorithms will be included to generate a worldwide map of RFI. As a novel addition to the 3Cat family of satellites and payloads, a hyper-spectral camera with 25 bands ranging from 600 to 975 nm will be used to obtain several indexes related to vegetation. By linking these measurements with the soil moisture obtained from the MWR, pixel downscaling can be attempted. Finally, a custom- developed LoRa transceiver will be included to provide a multi-level approach to in-situ sensors: On-demand executions of the other payloads will be able to be triggered from ground sensors if necessary, as well as simple reception of other measurements that will complement the ones obtained on the satellite. The antennas for both the MWR and the LoRa experiments have been developed in-house, and will span the entirety of one of the 3U sides of the satellite. In this work, the latest development advances will be presented, together with an updated system overview and information about the operations that will be conducted. Results obtained from the test campaign are also presented in the conference.

Thanks to the advances in the miniaturization and improved power consumption efficiency of electronics, computers, cell phone technologies, etc., today’s spacecrafts and payloads are reducing their size and increasing their performance. However, not all systems can be reduced, as their dimensions are determined by the laws of physics. This study is focused on the design of an L-band reflector antenna for a CubeSat-based Earth observation mission devoted to measure the surface soil moisture. Two configurations of deployable parabolic reflector antennas and meshes are presented from the mechanical point of view. The electromagnetic analyses including the antenna feeder are also presented. It is found that the regular circular mesh performs slightly better than the irregular one, although requires a more careful manufacturing process. This work was supported in part by the Project “Sensing With Pioneering Opportunistic Techniques-SPOT,” Spanish Agencia Estatal de Investigación under Grant RTI2018-099008-B-C21 and EU ERDF funds, and in part by UPC-CommSensLab María de Maeztu Unit under Grant MDM-2016-0600.

Throughout this study, the application of satellites in a Very Low Earth Orbit (VLEO) is analyzed to complement the already existing technologies used for vessels tracking. This study is part of the DISCOVERER project, which focuses on the research and development of VLEO technologies to apply them in Earth Observation (EO). Within the team, the UPC focuses on market analysis and the study of business opportunities for VLEO technologies. A value proposition is developed following the Canvas model, this being the strategy used to offer a service to a specific client. For the development of the value proposition, the study focuses on optimizing vessels tracking for maritime transport companies. A market study is carried out previously, to analyse how could the value proposition fit in it. The analysis determines that the optimal methodology and technologies to complement the platforms currently used for vessels tracking with an AIS system (Automatic Identification System) installed, is through Data Integration. This method refers to the combination of the data obtained by different platforms (satellites with different technologies and in different orbits complementing both, aerial and terrestrial platforms) once received in the ground station. For the tracking of those ships exempt from carrying an AIS transponder or those that do not want to be tracked, the optimal tracking method would be the combination of data between different platforms before being received on the ground station (System Integration).

Small satellites are becoming increasingly popular in several applications, in which attitude systems might require high precision performance. These spacecrafts are susceptible to magnetic disturbances in orbit, such as the interaction between the satellite and Earth’s magnetic field. However, a major disturbance torque is generated by the residual magnetic moment. Therefore, a magnetic cleanliness analysis must be considered in order to meet the requirements for magnetic-sensitive instruments and subsystems. Studies on magnetic environment management are underway for the FORESAIL-1 and FORESAIL-2 missions using the optical magnetic test bed of Aalto University. This is particularly important for FORESAIL-2 which aims to precisely measure the orbital ambient magnetic field with a high sensitivity magnetometer One of the parts of a spacecraft magnetic cleanliness analysis is the modelling of the residual magnetic moment as a set of magnetic dipoles. The dipoles are estimated from the measured magnetic field surrounded by the device-under-test (e.g., complete satellite, or its individual subsystems) using a stochastic estimation algorithm. The measurements are performed in a Helmholtz cage where the device and a low-noise magnetometer are placed, and detected by a smart camera using visual detection markers (ArUco). Information provided by the detection of the markers is then used for representing the position of the magnetometer and measured magnetic field points in the device-under-test coordinate frame. The camera detection accuracy is improved with data fusion from several ArUco markers, and the system performance is assessed by verifying the estimated magnetic moment results using known permanent magnets. Using this methodology for calculating the residual magnetic moment, the system is able to estimate the dipole’s position and magnetic vectors with a mean absolute error of 0.004 ± 9·10-7 m and 0.007 ± 1·10-4 A·m2 respectively. The test bed can be used for the characterization of the magnetic moment when measuring small satellites, or its components, in order to mitigate the residual magnetic moment.

This paper aims to facilitate getting acquainted with CubeSat preliminary design by presenting a review of open-source tools commonly used during project first steps, and a concrete example. The light but realistic preliminary design framework is based on a real 3U CubeSat use-case, the CREME project, relying on Nanospace and a package of selected Open-Source tools. This example should allow students and non-related field experts to fully grasp the concepts needed to achieve the basics of a typical preliminary design.

Global Navigation Satellite Systems reflectometry (GNSS-R) is a particular case of a multistatic radar in which the signals transmitted by navigation satellites are the signals of opportunity. These signals can be processed as a radar scatterometer, as a radar altimeter, or as an unfocused synthetic aperture radar. GNSS-R has shown its potential to infer numerous geophysical variables: over land soil moisture, vegetation height, detection of freeze-thaw state, etc., map sea ice extent and type…, and over the ocean wind speed and direction, significant wave height, altimetric measurements or even more recently NASA has released a marine plastics litter product, and some also claim that sea surface salinity (SSS)canbeinferred.Inaddition,retrievalalgorithmsneglectsome of the variations of the delay Doppler map (DDM) that are linked to the observation geometry, i.e., look angle with respect to the speed vectors of the transmitter and receiver. All these different effects impact the DDM peak value and its shape, and may affect the retrieval of geophysical parameters, and ultimately the data interpretation. In this study, the following factors impacting the DDM peak value are studied: the observation geometry, the sea surface temperature, and SSS, the 10 m height wind speed (U10) and direction (WD), the presence of foam, the sea development state, the presence of swell, currents, rain, and the presence of oil slicks perturbing the sea surface roughness. This illustrates the complexityofthechallengespresentedwhentryingtoretrievesome of these variables, the required corrections, and their accuracy., This work was supported in part by the Programa Estatal para Impulsar la Investigación Científico-Técnica y su Transferencia, del Plan Estatal de Investigación Científica, Técnica y de Innovación 2021-2023 (Spain) under Grant PID2021-126436OB-C21, in part by the European Social Fund, and in part by the GENESIS: GNSS Environmental and Societal Missions–Subproject UPC under Grant PID2021-126436OB-C21. (Corresponding author: Adriano Camps.)

The DISCOVERER project commenced in 2017 with the aim to advance the development of key technologies to enable the commercially viable, sustained operation of satellites in very low Earth orbits (VLEO). Funded by the European Commission through Horizon 2020, the project ends this month. This paper presents an overview of the key achievements and current status of the project. The project set out to advance the development of, and demonstrate, several technologies with the long-term aim of enabling the commercial use of VLEO. These technologies include: 1. aerodynamic materials which encourage specular scattering of the incoming flow to minimise drag and increase the performance of aerodynamic surfaces in the highly rarefied flows experienced in VLEO 2. aerodynamic attitude control methods to compensate for the dynamic flow environment, especially lower in the VLEO altitude range 3. atmosphere breathing electric propulsion (ABEP), combining an optimised atmospheric intake with advanced RF Helicon-based plasma thruster, for drag compensation DISCOVERER’s test satellite, the Satellite for Orbital Aerodynamics Research or SOAR, was deployed from the International Space Station in June 2021 and re-entered the atmosphere in March 2022. The primary aim was to measure the induced drag and lift on different aerodynamic materials candidates in VLEO by exposing panels, coated in various novel and control materials, to the flow at different orientations whilst observing the induced attitude and orbit perturbations produced. Early analysis of the results from the mission shows promising results for the novel materials developed as part of the project. Parallel studies on the long-term survivability of these materials to the space environment have been on-going through exposure tests on the exterior of the International Space Station through the MISSE programme. The project has also been developing a ground-based facility, the Rarefied Orbital Aerodynamics Research facility, to characterise the gas surface interaction properties of materials to atomic oxygen at orbital velocities. Characterisation of the facility itself is on-going. In support of ABEP technology, the experimental development and characterisation of an RF Helicon-based plasma thruster has been on-going, along with detailed computational modelling of aerodynamic intakes. Whilst the thruster has already been operated, current work focusses on the characterisation of its performance. Finally, work to place these technological developments into context has also been progressed. On overview of the overall achievements in this area is provided, including business modelling of the VLEO market ecosystem, which identifies the enormous market potential for VLEO missions. Peer Reviewed Article signat per 30 autors: Peter C.E. Roberts, Nicholas H. Crisp, Steve Edmondson, Antonio Arcos, Georg H. Herdrich, Jonathan Skalden, Silvia Rodriguez-Donaire, Daniel Garcia-Almiñana, Alejandro Macario-Rojas, Katharine L. Smith, Ciara Mcgrath, Sarah J. Haigh, Vitor T.A. Oiko, Brandon E.A. Holmes, Luciana A. Sinpetru, Virginia Hanessian, Simon Christensen, Thomas Kauffman Jensen, Jens Nielsen, Morten Bisgaard, Francesco Romano, Stefanos Fasoulas, Constantin Traub, Konstantinos Papvramidis, Miquel Sureda, Dhiren Kataria, Badia Belkouchi, Alexis Conte, Simon Seminari, Rachel Villain

Recent advancements in gamma-ray detector technology have brought new opportunities to study gamma-ray bursts and other high-energy phenomena. However, there is a lack of dissemination on the development methods, tools and techniques used in the production of instrument flight firmware. This is understandable as firmware for spacecraft payloads may be proprietary or exceptionally hardware specific and so is not always published. However, this leaves a gap in the knowledge for CubeSat teams, especially those consisting of university students who may be building a custom spacecraft payload with limited initial experience. The Gamma-Ray Module (GMOD) on-board EIRSAT-1, a 2U CubeSat in the 2nd European Space Agency Fly Your Satellite! programme, is one such instrument. GMOD features a 25x25x40mm Scionix CeBr3 scintillator, coupled to an array of 16 (4x4) JSeries OnSemiconductor MicroFJ-60035-TSV silicon photomultipliers (SiPMs) with readout provided by the SIPHRA IDE3380 application specific integrated circuit. The instrument is supported by the Gamma-Ray Module motherboard which controls and configures the instrument, providing regulated voltage and current sources as well as generating time tagged event packets and a temporary on-board flash storage. At the core of this system is the Texas Instruments MSP430FR5994 microcontroller. A custom firmware was produced for the instrument by the EIRSAT-1 team over numerous cycles of testing and development to reliably perform the long duration tasks of readout, storage and transfer of time tagged event data to the EIRSAT-1 on-board computer. Recognising the value of sharing our experiences and pitfalls on firmware development with the wider CubeSat community, this paper will provide an introduction to GMOD, with focus primarily on the development approach of the firmware. The development, testing, version control, essential tools and an overview of how the resources provided by the device manufacturer were used will be examined, such that the lessons learned may be extended to other payloads from student-led missions

Earth Observation satellite missions can provide global and frequent coverage. In the past decade we have seen an explosion of these missions based on three unit CubeSats, notably with Planet and Spire constellations of visible and near-infrared imagers and GNSS-Radio Occultations payloads. One of the most important parts of these type of payloads is the antenna, which is limited due to the dimensions of the CubeSats. Today, the largest deployable antenna for CubeSats has a diameter of 50 cm and it was part of RainCube rain radar. ESA is currently sponsoring two studies to develop a 1 m deployable reflector antenna for CubeSats. Although the most common solutions are the deployable reflectors, Fresnel Zone Plate antennas are a simple type of antennas that can overcome some of the technical limitations of these reflectors. In this paper we will present the design and tests of a deployable Fresnel Zone Plate antenna with 155 cm diameter, at a distance of 58 cm from the feeder. During the design, the modularity of the system has been considered, so that other antenna types can also be deployed. This antenna has a triangular shape, and each end is attached to a telescopic carbon fiber rod, which is deployed by means of a toothed belt that pushes them from its inner part. Each toothed belt is pushed with a DC motor. If accepted for a launch of opportunity, this antenna will be used in a GNSS-Radio Occultations payload onboard 3Cat-8, one of the future satellite missions of the UPC NanoSat Lab

The LEDSAT 1U Cubesat, a satellite roughly 10x10x11cm, was developed between late 2016 and 2021 by students of Sapienza University of Rome. The project was conceived with the help of the University of Michigan and started being developed by space engineering master students of Sapienza in a class context. The team of the S5Lab (Sapienza Space System and Space Surveillance Laboratory) continued the project and applied for the Fly Your Satellite! Programme of ESA Education, which has followed the development of the CubeSat, providing important expert support and periodic reviews. The approach brought to the students an invaluable educational experience as they participated actively in the development of a spacecraft with the typical milestones of satellite projects. The mission objectives of LEDSAT include the use of onboard LEDs for improved orbit determination, experimental attitude determination and backup light communication. Each of the six sides of the CubeSat houses an LED board of a different color (red, green, and blue) with opposite sides with paired color. The LEDs can flash a pattern predefined by radio telecommand and the light is observed using ground telescopes. The design of the spacecraft started in late 2016 and was presented at the selection workshop of the Fly Your Satellite! Programme in May 2017. Final assembly took place in mid-2020 after which the team performed functional and environmental testing between October and December 2020, with the objective of ensuring the survivability of the spacecraft in the space environment and characterization of its behavior. After successful testing, the spacecraft was integrated inside the deployer in July 2021 in Brno, Czech Republic and was launched from Kourou, French Guiana on August 17th, 2021, aboard the Vega VV19 launcher. The spacecraft is now in orbit and operating nominally, with the LED flashes having been observed several times. The development of the spacecraft was not without difficulty, with preventable issues arising through testing that imposed design changes and further analysis - the paper will walk through the project since its conception, throughout the development, the functional and environmental testing of the payload and at system level, emphasizing the lessons learned by the students.

This article presents the QuantSaT-PT project, an effort to create the first Portuguese nanosatellite for space to ground quantum communication. Focused on the Attitude Determination and Control System, it describes the different elements that allow for the attainment of diverse accuracy levels required for separate mission stages. Given the harsh pointing precision necessary for establishing a quantum downlink, the implementation of this module presents a major challenge in the Cubesat field. Furthermore, the introduced architecture aims to reduce system cost by replacing the state-of-the-art star tracker with ground beacon detection.

A Mach contest is part of an annual event, organized by UKLSL, which combines both CanSat and rocket competitions. The first Mach event in 2021 was focused on the design of “Simple and Advance CanSats”, and culminated on a 3-day activity at Machrihanish Airbase in Scotland. It involved setup, pre-flight checks, and system adjustments. This paper focuses on the design challenges, and outcomes from building a satellite the size of a soda can by reviewing the event, the mission designed for the competition, and students’ feedback on what could have been improved to prepare the next team competing in Mach-22 which would involve developing a Rocket design and launching an “Advance CanSat”. The competition allowed undergraduate students at The University of Nottingham to experience a practical learning style by solving real engineering problems and practicing professional development skills through design review presentations and providing a flight readiness review to the launch providers of the competition. The proposed mission statement was part of the “PEAK” category, which involved atmospheric studies, where it acts as a simulation model for measuring the atmosphere on different planets and as a deployable probe from rovers to measure varying atmospheric levels. The competition exposed students to perform AITV (Assembly, Integration, Testing, Verification) processes to their CanSat and constructed procedures to test and validate the recovery system. Results from the first Mach event prove a solid starting point for future CanSat competition and space activities within our university. In the future, there are aspirations to grow a student space society and get students involved in extra-curricular STEM (Science, Technology, Engineering, Math) projects, and allow them to apply the theory and concepts learned in their academics

This work aims at studying the mechanical behaviour of nano- and pico-satellites, with CubeSats and PocketQubes as the references, and designing and producing a deployment system for PocketQubes, to be integrated in a CubeSat platform. Through this project, the 3Cat-4 spacecraft will be analysied in order to assess the impact of changes made to its architecture, both at system and subsystem level, and the results evaluation will aid in decision making regarding modifications of the mechanical components. The analyses will serve as the reference for the mechanical testing during the Environmental Test Campaign (ETC). Additionally, the response of the spacecraft against the different vibro-acoustic and mechanical loads will serve as the starting point for the design of a PocketQube P-POD (Poly-Picosatellite Orbital Deployer), which will be a major subsystem integrated in 3Cat-8, a new mission of the NanoSat Lab currently in Phase B.

6G and beyond networks will merge communication and computation capabilities in order to adapt to changes. As they will consist of many sensors gathering information from its environment, new schemes for managing these large amounts of data are needed. For this purpose, we review Over the Air (OTA) computing in the context of estimation and detection. For distributed scenarios, such as a Wireless Sensor Network, it has been proven that a separation theorem does not necessarily hold, whereas analog schemes may outperform digital designs. We outline existing gaps in the literature, evincing that current state of the art requires a theoretical framework based on analog and hybrid digital-analog schemes that will boost the evolution of OTA computing. Furthermore, we motivate the development of 3D networks based on OTA schemes, where satellites function as sensors. We discuss its integration within the satellite segment, delineate current challenges and present a variety of use cases that benefit from OTA computing in 3D networks., Paper accepted in 2022 IEEE 21st Mediterranean Electrotechnical Conference (MELECON)

Non-terrestrial networks (NTN) are expected to play a key role in extending and complementing terrestrial 5G networks in order to provide services to air, sea, and un-served or under-served areas. This paper focuses the attention on the uplink, where terminals are able to establish a direct link with the NTN at Ka-band. To reduce the collision probability when a large population of terminals is transmitting simultaneously, we propose a grant-free access scheme called resource sharing beamforming access (RSBA). We study RBSA for low Earth orbit (LEO) satellite communications with massive multiple-input multiple-output (MIMO). The idea is to benefit from the spatial diversity to decode multiple overlapped signals. We have devised a blind and open-loop beamforming technique, where neither the receiver must carry out brute-force search in azimuth and elevation, nor are the terminals required to report channel state information. Upon deriving the theoretical throughput, we show that RBSA is appropriate for grant-free access to LEO satellite, it reduces the probability of collision, and thus it increases the number of terminals that can access the media. Practical implementation aspects have been tackled, such as the estimation of the required statistics, and the determination of the number of users. This work has received funding from the ministry of Science, Innovation, and Universities under project TERESATEC2017-90093-C3-1-R (AEI/FEDER,UE) and under grant RTI2018-099841-BI00 and from the Catalan Government (2017-SGR-1479).

Desde el comienzo de la era espacial, la filosofía de diseño de satélites estuvo dominada por diseños conservadores construidos con componentes altamente duraderos para soportar condiciones ambientales extremas. Durante las últimas dos décadas, la aparición de los CubeSats ha cambiado esta filosofía permitiendo todo un mundo de nuevas posibilidades. El despliegue de grandes constelaciones de CubeSats en órbita terrestre baja (LEO, en inglés) revolucionará el sector espacial al permitir ciclos de innovación más rápidos y económicos. Sin embargo, la confiabilidad de los CubeSats todavía se considera un obstáculo debido a las considerables tasas de fallo entre universidades y empresas, generalmente atribuidas a casos de pérdida completa de misión tras la eyección del desplegador orbital y al fallo de los subsistemas. Esta tesis se desarrolla en el marco del proyecto de investigación PLATHON, que pretende desarrollar una plataforma de emulación Hardware-in-the-loop para constelaciones de nanosatélites con comunicación óptica entre satélites y enlaces tierra-satélite. Un aspecto crucial de este proyecto es tener un propagador orbital suficientemente preciso con control de maniobras y representación gráfica en tiempo real. Los programas de propagadores disponibles se han analizado para seleccionar el sistema OpenSatKit de la NASA, una plataforma multifacética con un propagador incorporado conocido como 42. El propósito de esta disertación es analizar la viabilidad de implementación del programa para la creación de un banco de pruebas de constelaciones en comparación con un propagador previo desarrollado en MATLAB/Simulink. La documentación inicial es un enfoque de exploración para examinar las capacidades del 42 en distintos escenarios con objeto de adaptar el sistema PLATHON al funcionamiento interno y las limitaciones del programa. Las modificaciones y simulaciones del programa allanan el camino para el futuro desarrollo de la red interconectada PLATHON; específicamente, las comunicaciones entre procesos se han probado para imitar las entradas de los sistemas de control de actitud de las naves espaciales a través de interfaces de comunicación bidireccionales. Since the beginning of the space age, satellite design philosophy was dominated by conservative designs built with highly reliable components to endure extreme environmental conditions. During the last two decades, the dawn of the CubeSats has changed this philosophy enabling a whole world of new possibilities. The deployment of monumental CubeSat constellations in low Earth orbit is set to revolutionise the space sector by enabling faster and economical innovation cycles. However, CubeSat reliability is still considered an obstacle due to the sizeable fail rates among universities and companies, generally attributed to the dead-on-arrival cases and subsystem malfunctions. This thesis is developed in the framework of the PLATHON research project that intends to develop a Hardware-in-the-loop emulation platform for nanosatellite constellations with optical inter-satellite communication and ground-to-satellite links. A crucial aspect of this project is to have a sufficiently precise orbital propagator with real-time manoeuvring control and graphical representation. The available propagator programmes are analysed to select NASA’s OpenSatKit, a multi-facet platform with an inbuilt propagator known as 42. The purpose of this dissertation is to analyse the implementation feasibility of the programme for the creation of a constellation testing bench compared to previously selfdeveloped propagators based on MATLAB/Simulink. The initial documentation is a scouting approach to examine 42’s capabilities under distinct scenarios to adapt the PLATHON system to the programme’s inner workings and constraints. The programme modifications and simulations pave the way for the future development of the interconnected PLATHON network; specifically, the inter-process communication capabilities have been tested to imitate the inputs of spacecraft attitude control systems through bidirectional socket interfaces.

PLATHONs main mission is to simulate a Networks System of CubeSats that collects information and communicate with other different orbital group satellites using IoT sensors to retrieve the information towards a ground station minimizing delay and maximizing global coverage. The project's overview encompasses an analytical estimation of the worst-case disturbance torques calculations for the mission. Moreover, a detailed control algorithm is developed for fine pointing and coarse pointing modes in the orbit as well as a 3D real-time monitoring interface. Finally, the design of the Reaction Wheel is also made following the technical requirements set by the project specifications. To perform the simulation, the CubeSat is introduced in an Air bearing in the center of a magnetic simulator, which will generate a magnetic field similar to the conditions that the satellite will be subjected in a Low Earth Orbit. El siguiente proyecto se realiza dentro de PLATHON (Plataforma de comunicaciones ópticas en nanosatélites) del proyecto DISEN y del Grupo de Investigación TIEG liderado por el Dr. David González y el Dr. Javier Gago en la ESEIAAT (Escola Superior d’Enginyeries Industrial, Audiovisual i Aeronàutica de Terrassa) de la Escuela Politécnica de Cataluña - BarcelonaTech. La misión principal de PLATHON es simular un Sistema de redes de CubeSats que recoja información y se comunique con otros satélites de diferentes grupos orbitales utilizando sensores IoT para recuperar la información hacia una estación terrestre minimizando el retraso y maximizando la cobertura global. Estudiantes de último curso de grado y máster de varios departamentos son los principales colaboradores del proyecto y la mayoría de los componentes del sistema están diseñados y construidos por los estudiantes. La siguiente tesis comprende una estimación analítica de los cálculos de los pares de perturbación en el peor de los casos para la misión. Además, se desarrolla un algoritmo de control detallado para los modos de apuntamiento fino y grueso en la órbita, así como una interfaz de monitorización 3D en tiempo real. Por último, el diseño de la Rueda de Reacción (RW) también se realiza siguiendo los requisitos técnicos establecidos por las especificaciones del proyecto. La etapa final del proyecto se centra en la realización de pruebas y la simulaciones de los algoritmos de control implementados. Para realizar la simulación, se introduce el CubeSat en un cojinete de aire en el centro de un simulador magnético, que generará un campo magnético similar a las condiciones a las que estará sometido el satélite en una órbita baja terrestre (LEO). El ordenador de a bordo (OBC) del nanosatélite se comunica vía Bluetooth con el ordenador de tierra a la espera de órdenes (en este caso, el ordenador central del laboratorio). La estación de tierra tiene acceso total a la actitud del satélite y control total sobre los distintos modos del satélite (es decir, modo de Detumbling, modo de apuntamiento, modo normal, entre otros). Una vez fijado el campo magnético y otras fuentes de perturbación, las ruedas de reacción y los magnetorquers se activarán para controlar la actitud del CubeSat. Análogamente, estos datos de actitud medidos por la Unidad de Medición Inercial (IMU) del Subsistema de Determinación y Control de Actitud (ADCS) se envían de vuelta al ordenador de la estación de tierra y se visualizan además con un modelo 3D generado por ordenador en tiempo real. El CubeSat está pensado para ser alimentado tanto con paneles solares como con una batería LiPo. La realización de una prueba de software-in-theloop y de hardware-in-the-loop ha demostrado que el sistema requiere algunas modificaciones para lograr resultados más precisos.

Carreno-Luengo, H., et al., The Institute of Electrical and Electronics Engineers (IEEE) Geoscience and Remote Sensing Society (GRSS) created the GRSS 'Standards for Earth Observation Technical Committee' to advance the usability of remote sensing products by experts from academia, industry, and government through the creation and promotion of standards and best practices. In February 2019, a Project Authorization Request was approved by the IEEE Standards Association (IEEE-SA) with the title 'Standard for Spaceborne Global Navigation Satellite Systems Reflectometry (GNSS-R) Data and Metadata Content.' At present, 4 GNSS constellations cover the Earth with their navigation signals: The United States of America (USA) Global Positioning System GPS with 31 Medium Earth Orbit (MEO) operational satellites, the Russian GLObal'naya NAvigatsionnaya Sputnikovaya Sistema GLONASS with 24 MEO operational satellites, the European Galileo with 24 MEO operational satellites, and the Chinese BeiDou-3 with 3 Inclined GeoSynchronous Orbit (IGSO), 24 MEO, and 2 Geosynchronous Equatorial Orbit (GEO) operational satellites. Additionally, several regional navigation constellations increase the number of available signals for remote sensing purposes: the Japanese Quasi-Zenith Satellite System QZSS with 1 GSO and 3 Tundra-type orbit operational satellites, and the Indian Regional Navigation Satellite System IRNSS with 3 GEO and 4 IGSO operational satellites. On the other hand, there are different GNSS-R processing techniques, instruments and spaceborne missions, and a wide variety of retrieval algorithms have been used. The heterogeneous nature of these signals of opportunity as well as the numerous working methodologies justify the need of a standard to further advance in the development of GNSS-R towards an operational Earth Observation technique. In particular, the scope of this working group is to develop a standard for data and metadata content arising from past, present, and future spaceborne missions such as the United Kingdom (UK) TechDemoSat-1 TDS-1, and the National Aeronautics and Space Administration (NASA) CYclone Global Navigation Satellite System CYGNSS constellation coordinated by the University of Michigan (UM). In this article we describe the scene study, including fundamental aspects, scientific applications, and historical milestones. The spaceborne standard is under development and it will be published in IEEE-SA., 10.13039/100000104-National Aeronautics and Space Administration (NASA) Science Mission Directorate with the University of Michigan (Grant Number: NNL13AQ00C)

In the last few years, space agencies have deployed a large number of Earth-observing satellites and the key towards their full exploitation is fully automated analysis methods, which call for new tools to extract reliable and expressive information. Taking into account the free availability of not very high-resolution satellite images like those provided by the Sentinel-2, we propose to explore deep learning models to combine semantic segmentation and super-resolution in a multi-task approach. We implement our model by modifying a well-known state-of-the-art architecture, i.e., DeepLabv3+, and train it into the S2GLC 2017 dataset, which belongs to land cover segmentation of satellite imagery. We conduct several experiments to design the model architecture that achieves the best results. Finally, we assess both quantitatively and qualitatively the segmentation and super-resolution attained results, and present the major advantages in working with reduced input images while making use of the whole ground truth information. En los últimos años, las agencias espaciales han desplegado una gran cantidad de satélites de observación de la Tierra y la clave para su plena explotación son los métodos de análisis totalmente automatizados, que requieren nuevas herramientas para extraer información confiable y expresiva. Teniendo en cuenta la disponibilidad gratuita de imágenes satelitales de no muy alta resolución como las proporcionadas por Sentinel-2, proponemos explorar modelos de aprendizaje profundo para combinar la segmentación semántica y la superresolución en un enfoque multitarea. Implementamos nuestro modelo modificando una arquitectura de vanguardia conocida, i.e., DeepLabv3+, y lo entrenamos en el conjunto de datos S2GLC 2017, que corresponde a la segmentación de la cobertura terrestre de imágenes satelitales. Realizamos varios experimentos para diseñar la arquitectura del modelo que logre los mejores resultados. Por último, evaluamos tanto cuantitativa como cualitativamente los resultados de segmentación y superresolución obtenidos, y presentamos las principales ventajas de trabajar con imágenes de entrada reducidas mientras hacemos uso de toda la información de las etiquetas de referencia. En els últims anys, les agències espacials han desplegat una gran quantitat de satèl·lits d'observació de la Terra i la clau per a la seva plena explotació són els mètodes d'anàlisi totalment automatitzats, que requereixen noves eines per extreure informació fiable i expressiva. Tenint en compte la disponibilitat gratuïta d'imatges satel·litals de no molt alta resolució com les proporcionades per Sentinel-2, proposem explorar models d'aprenentatge profund per combinar la segmentació semàntica i la superesolució en un enfocament multitasca. Implementem el nostre model modificant una arquitectura d'avantguarda coneguda, i.e., DeepLabv3+, i l'entrenem en el conjunt de dades S2GLC 2017, que correspon a la segmentació de la cobertura terrestre d'imatges de satèl·lit. Realitzem diversos experiments per dissenyar l'arquitectura del model que aconsegueixi els millors resultats. Finalment, avaluem tant quantitativa com qualitativament els resultats de segmentació i superresolució obtinguts, i presentem les principals avantatges de treballar amb imatges d'entrada reduïdes mentre fem ús de tota la informació de les etiquetes de referència.

En aquest estudi s'evalua la sensibilitat del sistema GLM (Geostationary Lightning Mapper) davant els fotòmetres de MMIA (Modular Multispectral Imaging Array), en concret el fotòmetre 3 captant llum a 777.4nm de longitud d'ona. Per a fer-ho, les dades de GLM i MMIA son extrets dels fitxers amb informació preprocessada per LCFA (Lightning Cluster Filter Algorithm) -dades classificades per temps, geolocalització, intensitat de la detecció i amb un número identificatiu- per a posteriorment ser tractats mitjançant la classificació de les seves senyals en deteccions donades per la xarxa de detecció de rajos Linet a Colombia, sincronització de senyals i comparació de pics de senyal. En este estudio se evalúa la sensibilidad del sistema GLM (Geostationary Lightning Mapper) frente a la de los fotómetros de MMIA (Modular Multispectral Imaging Array), en concreto el fotómetro 3 captando la luz en 777.4 nm de longitud de onda. Para ello, tanto los datos de GLM como de MMIA son extraídos de los ficheros con información preprocesada por LCFA (Lightning Cluster Filter Algorithm) -datos clasificados por tiempo, geolocalización, intensidad de la detección y con un número identificativo- para posteriormente ser tratados mediante la clasificación sus señales en detecciones dadas por la red de detección de rayos Linet en Colombia, sincronización de señales y comparación de picos de señal. This study evaluates the sensitivity of the Geostationary Lightning Mapper (GLM) versus the Modular Multispectral Imaging Array (MMIA)'s photometer 3, both operating at the oxygen band at 777.4nm of wavelength. To do so, both GLM's and MMIA's data is extracted from pre-processed data files by a Lightning Cluster Filter Algorithm (LCFA) -data classified by time, geolocalization, detection intensity and with an ID number- to be treated by classification of their signals according to Linet Lightning Mapper Array (LMA) detections in Colombia, signal synchronization and peak comparison.

Obtaining global terrestrial data in real time has become one of the most powerful scientific challenges of today and using satellites and nano satellites we can receive the necessary information to solve this task. In 2009 ESA (European Space Agency) launched the SMOS (Soil Moisture and Ocean Salinity) satellite with the objective of capturing global data using innovative techniques in order to obtain soil moisture and ocean salinity maps every 3 days. The access to this information allowed the development of new scientific studies in order to understand the functioning of the different water cycles in our planet and try to understand what alterations it has suffered over the years due to human activity. The TSC (Signal and Communications Theory) department of the UPC (Universitat Politècnica de Catalunya) participates in the processing of the data obtained by SMOS since its launch. The project developed in the following document aims to obtain a new model of the ocean developed by the BEC (Barcelona Expert Center), a research center that also participates in different SMOS data processing tasks. In order to carry out this task, we have had to work together to adapt the procedures to obtain the model so that it is useful in the TSC working environment. After several months of work, the procedure was correctly established and today we have been able to obtain the first years of modeled ocean. Obtaining the new model opens the door to new studies to evaluate the state of the satellite and the quality of the data obtained by it, since it is more than 10 years of its launching and all hardware has a limited useful life. By means of models, it is possible to obtain a very useful type of graphs, the Hovmoller graphs. This allow to obtain the difference between the results obtained from the model and the measurements taken by the SMOS and to be plotted. Once the processing to obtain the BEC model has been completed, Hovmollers obtained from it might bring to relevant conclusions. La obtención de datos globales Terrestres a tiempo real se ha convertido en uno de los retos científicos más poderosos de hoy en día y mediante el uso de satélites y nano satélites podemos recibir la información necesaria para resolver dicha tarea. En el año 2009 la ESA (Agencia Espacial Europea) lanzó el satélite SMOS (Soil Moisture and Ocean Salinity) con el objetivo de captar datos globales mediante técnicas innovadoras con el fin de obtener mapas de humedad del suelo y salinidad de los océanos cada 3 días. El acceso a dicha información permitió desarrollar nuevos estudios científicos con el fin de entender el funcionamiento de los diferentes ciclos que vive el agua en nuestro planeta e intentar entender qué alteraciones ha sufrido a lo largo de los años debido a la actividad humana. El departamento TSC (Teoría de Señal y Comunicaciones) de la UPC (Universitat Politècnica de Catalunya) participa en el procesado de los datos obtenidos por el SMOS desde su lanzamiento. El proyecto desarrollado en el siguiente documento tiene como objetivo la obtención de un nuevo modelo del océano desarrollado por el BEC (Barcelona Experto Center), centro de investigación que también participa en diferentes tareas de procesado de datos del SMOS. Para llevar a cabo esta tarea, hemos tenido que trabajar conjuntamente para adecuar los procedimientos de obtención del modelo para que sea útil en el entorno de trabajo del TSC. Después de diferentes meses de trabajo, se pudo establecer correctamente el procedimiento y a día de hoy se han podido obtener los primeros años de océano modelado. La obtención del nuevo modelo abre las puertas a nuevos estudios que permitan evaluar el estado del satélite y la calidad de los datos obtenidos por este, puesto que hace más de 10 años de su lanzamiento y todo hardware tiene una vida útil limitada. Mediante modelos, se pueden obtener un tipo de gráficas muy útiles a golpe visual, las gráficas Hovmoller. Estas permiten dibujar la diferencia que hay entre los resultados obtenidos del modelo y las medidas tomadas por la SMOS. Una vez se haya completado el procesado de obtención del modelo del BEC se pretende obtener Hovmollers a partir de este para que mediante su posterior análisis se pueda llegar a extraer conclusiones relevantes. L'obtenció de dades globals Terrestres a temps real s'ha convertit en un dels reptes científics més poderosos d'avui en dia i mitjançant l'ús de satèl·lits i nano satèl·lits podem rebre la informació necessària per resoldre aquesta tasca. L'any 2009 l'ESA (Agència Espacial Europea) va llençar el satèl·lit SMOS (Soil Moisture and Ocean Salinity) amb l'objectiu de captar dades globals mitjançant tècniques innovadores amb el fi d'obtenir mapes d'humitat del sòl i salinitat dels oceans cada 3 dies. L'accés a llur informació va permetre desenvolupar nous estudis científics amb el fi d'entendre el funcionament dels diferents cicles que viu l'aigua en el nostre planeta i intentar entendre quines alteracions ha patit al llarg dels anys degut a l'activitat humana. El departament TSC (Teoria de Senyal i Comunicacions) de la UPC (Universitat Politècnica de Catalunya) participa en el processat de les dades obtingudes per l'SMOS des del seu llançament. El projecte desenvolupat en el següent document té com a objectiu l'obtenció d'un nou model de l'oceà desenvolupat pel BEC (Barcelona Expert Center), centre d'investigació que també participa en diferents tasques de processat de dades de l'SMOS. Per tal de dur a terme aquesta tasca, hem hagut de treballar conjuntament per tal d'adequar els procediments d'obtenció del model per a que sigui útil en l'entorn de treball del TSC. Després de diferents mesos de feina, es va poder establir correctament llur procediment i a dia d'avui s'han pogut obtenir els primers anys d'oceà modelat. L'obtenció del nou model obra les portes a nous estudis que permetin avaluar l'estat del satèl·lit i la qualitat de les dades obtingudes per aquest, ja que fa més de 10 anys del seu llançament i tot hardware té una vida útil limitada. Mitjançant models, és poden obtenir un tipus de gràfiques molt útils a cop visual, les gràfiques Hovmoller. Aquetes permeten dibuixar la diferència que hi ha entre els resultats obtinguts del model i les mesures preses per l'SMOS. Una vegada s'hagi completat el processat d'obtenció del model del BEC es pretén obtenir Hovmollers a partir d'aquest per a que mitjançant un posterior anàlisis es pugui arribar a extreure conclusions rellevants.

The emerging interest in satellite networks will be a key driver in the path to 6G. The satellite segment must be conceived beyond a mere relay system, where nodes can process data and offload the terrestrial segment. Besides, evidence suggests that energy consumption is among the most important factors for the design of future communication networks. For this motivation, we introduce Sat2C, an energy-efficient algorithm for satellite joint routing, radio resource allocation and task offloading for latency-constrained services. We develop a novel energy model that incorporates the power amplifier subsystem and changes the geometry of the problem. Regarding the routing task, we propose the SHIELD algorithm, based on the submodularity framework and which achieves Pareto-efficient routes. Besides, the RRM problem is formulated as a log-log convex program. The experimental results reveal that Sat2C has low computational complexity, provides routes with low variance in the mean distance and the transmission powers are optimal to ensure energy minimization.

The use of very low Earth orbits (VLEO), for communications and remote sensing satellites, offers a number of significant payload and platform benefits. Imaging from these altitudes allows higher resolution or smaller optical payloads, whilst radar also benefits from improved link budgets leading to smaller antennas and lower transmission power. Communications payloads also have improved link budgets, reduced latency, and improved frequency reuse factors. Platform benefits include a more benign radiation environment, lower cost per kilogram to launch satellites, and atmospheric drag makes the environment inherently sustainable, simultaneously removing debris objects and ensuring satellites are quickly removed from orbit at the end of their operational lives. However, the impact of drag on satellite and mission operations must also be addressed. The DISCOVERER project, which commenced in 2017, is addressing the following key questions about technologies that would enable the commercially viable and sustained operation of satellites in VLEO: 1. Are there materials or processes which reduce the induced drag on spacecraft surfaces? 2. Are there propulsion methods which use the residual atmospheric gas as a propellant, providing drag compensation whilst removing the lifetime limits caused by carrying a limited amount of propellant? 3. How can we improve our understanding of, and make best use of, the orbital aerodynamics of a space platform and its ability to perform attitude control manoeuvres? 4. And what are the new opportunities that these technologies may bring to the market? This paper provides highlights from the developments made during the DISCOVERER project to date, demonstrating the potential for a new, commercially attractive, class of aerodynamic satellites operating in VLEO. Article signat per 30 autors: Peter C.E. Roberts, Nicholas H. Crisp, Vitor T.A. Oiko, Steve Edmondson, Francesco Romano, Silvia Rodriguez-Donaire, Daniel Garcia-Almiñana, Sarah J. Haigh, Brandon E.A. Holmes, Sabrina Livadiotti, Alejandro Macario-Rojas, Katharine L. Smith, Luciana A. Sinpetru, Jonathan Becedas, Valeria Sulliotti-Linner, Simon Christensen, Thomas K. Jensen, Jens Nielsen, Morten Bisgaard, Yung-An Chan, Georg H. Herdrich, Stefanos Fasoulas, Constantin Traub, Miquel Sureda, Dhiren Kataria, Badia Belkouchi, Alexis Conte, Simon Seminari, Rachel Villain, Ameli Schwalber. Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

Nowadays a large number of artificial satellites orbit the Earth, of which many of them have completed their mission or are fragments of satellites that travel without any purpose. These objects can pose a collision problem for other active missions, so these inactive satellites need to be tracked. The highest concentration of inactive satellites is found in LEO orbits, from where due to the effect of aerodynamic drag, a function of density, the satellite will end up re-entering the atmosphere. The density parameter is influenced by solar and geomagnetic activity. Currently, thermospheric density models are available to estimate density, necessary for orbital prediction. The aim of this project is to study how solar and geomagnetic activity changes density, and therefore the orbital evolution of the satellite in the thermosphere. The second objective is to determine the goodness of the NRLMSISE-00 thermospheric density model. For the first objective, the TLEs of satellites that are in periods of maximum solar activity have been analyzed. From the code made with Matlab these TLE files have been read and the epoch, the semi-major axis and the eccentricity have been extracted. The evolution of these last two parameters has been analyzed in the presence of solar activity, in the form of solar flare. For the second objective, to determine the goodness of the NRLMSISE-00 model, in the first place the density has been calculated from parameters obtained from the TLEs, at the same time, from the Matlab package NRLMSISE-00 the density that estimates the NRLMSISE-00 model for the same dates. Finally, results have been compared. However, the TLEs data are associated with a prediction error, which is unknown. Therefore, based on the DOPs (Precise Orbit Determination) of the GFZ-1 satellite, provided by the GFZ German Research Center for Geociences, it has been analyzed the error TLEs make in the prediction of the semi-major axis compared to the semi-axis obtained with greater precision from the DOPs.

The objective of this Final Degree Thesis is to design and build a deployable parabolic reflector for a CubeSat. An optimal shape for the reflector has been studied and proposed, and the relationship of surface accuracy with electromagnetic performance has also been studied. The proposed result, based on the previous studies carried out, consisted of holding and shaping the parabolic reflector from tensioned threads. Possible materials for the reflector surface have been analyzed and tested: starting with different types of wire mesh, then with a metallized thermal blanket. After testing it was found that both options could be used as a reflective RF surface. A geometric study and electromagnetic simulations with CST have been carried out to find out what was the optimal opening angle and incidence angle of the masts to have the largest possible parabolic reflector. Based on these results, a prototype has been designed and built to be tested in an anechoic chamber. Finally, an origami pattern of the prototype reflector surface has been designed and simulated and it has been proposed as a feasible possibility of implementation. El objetivo de este Trabajo Final de Grado ha sido diseñar y construir un reflector parabólico para un CubeSat. Se ha estudiado y propuesto una forma óptima para el reflector, así como la relación entre la precisión de la superficie con la eficiencia. A partir de los estudios previos realizados, el resultado propuesto ha consistido en sujetar y dar forma al reflector parabólico a partir de hilos tensados. Se han analizado y probado posibles materiales para la superficie del reflector: primero diferentes tipos de mallas metálica con cables y posteriormente una manta térmica metalizada. Tras las pruebas se ha descubierto que ambas opciones son viables como una superficie reflectante de RF. Se ha realizado un estudio geométrico y simulaciones electromagnéticas con CST para averiguar cuál era el ángulo de apertura y el ángulo de incidencia óptimos de los mástiles para tener el mayor reflector parabólico posible. A partir de estos resultados se ha diseñado y construido un prototipo para ser medido en cámara anecoica. Finalmente se ha diseñado y simulado un patrón de origami de la superficie del reflector prototipo y se ha propuesto como una posibilidad factible de implementación. L'objectiu d'aquest Treball Final de Grau ha estat dissenyar i construir un reflector parabòlic per a un CubeSat. S'ha estudiat i proposat una forma òptima per al reflector, així com la relació entre la precisió de la superfície amb l'eficiència. A partir dels estudis previs realitzats, el resultat proposat ha consistit en subjectar i donar forma al reflector parabòlic a partir de fils tensats. S'han analitzat i provat possibles materials per a la superfície de l'reflector: primer diferents tipus de malles metàl·liques amb cables i posteriorment una manta tèrmica metal·litzada. Després de les proves s'ha descobert que les dues opcions són viables com una superfície reflectant de RF. S'ha realitzat un estudi geomètric i simulacions electromagnètiques amb CST per esbrinar quin era l'angle d'obertura i l'angle d'incidència òptims dels pals per tenir el major reflector parabòlic possible. A partir d'aquests resultats s'ha dissenyat i construït un prototip per a ser mesurat en cambra anecoica. Finalment s'ha dissenyat i simulat un patró d'origami de la superfície de l'reflector prototip i s'ha proposat com una possibilitat factible d'implementació.

El proyecto se basa en realizar un software en MATLAB, u otra plataforma a determinar, que integre un simulador de órbitas, que ya se ha desarrollado en un proyecto anterior, en una plataforma de cubesats en el laboratorio, que se van a enviar datos entre ellos. La plataforma consta de un conjunto de nanosatélites en forma de cubo de 1x1x1 dm de dimensión (cubesat). Además de los datos entre cubesats, cada uno enviará, mediante bluetooth, información on-line del consumo de baterías, ángulo de inclinación y estado de la comunicación con otro cubesat. El simulador presentará en pantalla la posición de los cubesats en función de los datos de lanzamiento (simulados) y el tiempo transcurrido desde el mismo. También girará los cubesats según el ángulo real que tenga, en coordenadas terrestres, cada cubesat de la plataforma del laboratorio. Este ángulo se obtiene mediante subsistemas ya desarrollados con anterioridad a este proyecto. También mostrará datos de carga de batería y de consumo en el acto de comunicación de datos, que se obtendrán del subsistema de potencia que se diseña en otro proyecto.

Invoice factoring is a handy tool for developing businesses that face liq- uidity problems. The main property that a factoring system needs to fulfill is to prevent an invoice from being factored twice. Distributed ledger tech- nology is suitable for implementing the platform to register invoice factor- ing agreements and prevent double-factoring. Several works have been proposed to use this technology for invoice factoring. However, current proposals lack in one or several aspects such as decentralization and secu- rity against corruption, protecting business and personally identifiable in- formation (PII), providing non-repudiation for handling disputes, Know- Your-Customer (KYC) compliance, easy user on-boarding, and being cost- efficient. In this article, a factoring registration protocol is proposed for invoice factoring registration based on a public distributed ledger which adheres to the before-mentioned requirements. We include a relayer in our architecture to address the entry barrier that the users have due to the need of managing cryptocurrencies for interacting with the public ledger. Moreover, we leverage the concept of Verifiable Credentials (VCs) for KYC compliance, and allow parties to implement their self-sovereign identities by using decentralized identifiers (DIDs). DIDs enable us to relay on the DIDComm protocol for asynchronous and secure off-chain communica- tions. We analyze our protocol from several security aspects, compare it to the related work, and study a possible business use case. Our evalu- ations demonstrate that our proposal is secure and efficient, and covers requirements not addressed by existing related work. This research has been funded by i3Market (H2020-ICT-2019-2 grant number 871754). This work is also supported by the TCO-RISEBLOCK (PID2019-110224RB-I00), ARPASAT (TEC2015- 70197-R), and by the Generalitat de Catalunya grant 2014-SGR-1504.

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This study addresses a novel application of global navigation satellite system-reflectometry (GNSS-R) delay-Doppler maps (DDMs), namely sea target detection. In contrast with other competing remote sensing technologies, such as synthetic aperture radar and optical systems, typically exploited in the field of sea target detection, GNSS-R systems could be employed as satellite constellations, so as to fulfill the temporal requirements for near real-time ships and sea ice sheets monitoring. In this study, the revisit time offered by GNSS-R systems is quantitatively evaluated by means of a simulation analysis, in which three different realistic GNSS-R missions are simulated and analyzed. Then, a sea target detection algorithm from spaceborne GNSS-R DDMs is described and assessed. The algorithm is based on a sea clutter compensation step and uses an adaptive threshold to take into account spatial variations in the sea background and/or noise statistics. Finally, the sea target detector algorithm is tested and validated for the first time ever using experimental GNSS-R data from the U.K. TechDemoSat-1 dataset. Performance is assessed by providing the receiver operating characteristic curves, and some preliminary experimental results are presented.

The Earth Observation market is experiencing a liberalisation led by the evolution of the New Space concept, in which disruptive companies and users are joining the race. The manufacturing of Small Satellites and the production of satellite images and its availability are the main drivers of this study: a modelization which aims to improve the knowledge of the relation between the cost and the value for InfraRed applications in Small Satellite payloads operating at Low and Very Low Earth Orbits.

The aim of this proposal is to establish the business model for a new company operating in the VLEO market to launch small satellites for Earth Observation missions. This thesis is about thedesign of a businessmodelfor a micro-launchercompany operating in Very Low Earth Orbit (VLEO) missionsafter apreliminarybut extensive study ofthe industry:the current political,social, technological and economical environments. Several tools, models and methodologies such as marketing mix, swot, risk analysis or even Michael Porter’s Value chain are used in order to better understandhow thefictionalentitybeing studied would need to behave and act in order to succeed.

The fast development in the production of small, low-cost satellites is propelling an important increase in satellite mission planning and operations projects. Central to satellite mission planning is the resolution of scheduling problem for an optimised allocation of user requests for efficient communication between operations teams at the ground and spacecraft systems. The aim of this paper is to survey the state of the art in the satellite scheduling problem, analyse its mathematical formulations, examine its multi-objective nature and resolution through meta-heuristics methods. Finally, we consider some optimisation problems arising in spacecraft design, operation and satellite deployment systems