Search

This thesis presents the development and implementation of the Attitude Determination and Control System (ADCS) for the 3cat-8 satellite, a project undertaken by the UPC NanoSat Lab. The ADCS is essential for maintaining the desired orientation of the satellite, which is crucial for performing scientific experiments, gathering solar power and communicating with the ground station. This work primarily focuses on the complete modeling of a satellite using a hybrid Magnetorquer + Reaction wheel actuator scheme, and the control algorithms that needed to obtain and maintain a desired orientation during flight. Various options for representing attitude in space are explored, with quaternions chosen as the basis for the attitude determination and control algorithms. Space dynamics are also thoroughly examined in order to create the backbone for a simulation software with which the control laws will be tested and validated. To ensure that the simulation environment closely mirrors reality, state-of-the-art environmental models of the Earth are studied and implemented. Additionally, the disturbances acting upon the satellite are deeply analyzed and characterized, employing numerical and statistical methods to obtain accurate yet computationally efficient implementations of said disturbances. The actuation scheme has been found to impact the control algorithms used for attitude control in the pointing modes, creating the need for allocating the control commands across the actuator suite, as well as unloading the angular momentum stored in the reaction wheel. The final satellite model and the selected control laws have been tested in the simulated environment, demonstrating their correct functioning and mostly fulfilling the operational requirements initially set for the 3cat-8 satellite. The thesis concludes with suggestions for possible improvements in the attitude control scheme and recommendations for future work.

The Remote sensing and Interference detector with radiome-Try and vegetation Analysis (RITA) payload was selected in 2019 the 2nd GRSS Student Grand Challenge to fly onboard AlainSat-1, a 3U CubeSat developed at the National Space Science and Technology Center (NSSTC) in United Arab Emirates. RITA payload includes a passive Microwave Radiometer (MWR), a LoRa transceiver, and an hyper-spectral camera. The objective of the payload is to retrieve Earth Observation (EO) parameters such as: soil moisture, sea-ice thickness and concentration, among others. A Radio Frequency Interference (RFI) detection algorithm is also included to the payload to create interference maps in the received signals., This project is supported and funded by the IEEE Geoscience and Remote Sensing Society (GRSS), as one of the winners of the 2nd IEEE GRSS Student Grand Challenge, and supported grants for recruitment of early-stage research staff of Agencia Gestió d’Ajuts Universitaris i de Recerca (AGAUR) Generalitat de Catalunya, Spain (FI2019/1183, FISDUR2020/105, FI2022/809, and FI2023/239). This article was part of the project ”GENESIS: GNSS Environmental and Societal Missions – Subproject UPC”, Grant PID2021-126436OB-C21 funded by the Ministerio de Ciencia e Investigacion (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 and EU FEDER “Una manera de hacer Europa”., Peer Reviewed, Postprint (author's final draft)

Earth observation satellite missions are becoming increasingly important and have been also boosted by the appearance of small satellites, affordable to small companies and universities. Technology miniaturization and the reduction in power consumption have been a key point in the reduction of the dimensions of these spacecrafts, being able to integrate powerful payloads in a very limited space. In missions where the observations are made at lower frequency bands, the antenna dimensions limit the achievable angular resolution. For this reason, significant investments are being made to develop antenna deployment systems for small satellites, and the deployable antennas themselves.This work presents the design and prototyping of a deployable Fresnel Zone Plate antenna for CubeSats. The first model is a technical demonstrator, but it is also meant for a GNSS-Radio Occultations payload on a 6U CubeSat. Due to its characteristics and modularity it could be easily redesigned and modified to be used in communications, etc. at other frequency bands., This project was part of the project ”GENESIS: GNSS Environmental and Societal Missions – Subproject UPC”, Grant PID2021-126436OB-C21 funded by the Ministerio de Ciencia e Investigación (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 and EU FEDER “Una manera de hacer Europa”., Peer Reviewed, Postprint (author's final draft)

Due to the recent licensing of the 26 GHz 5G communications bands, the passive microeaves Remote Sensing community is concerned that spurious out-of-band emissions could interfere with the measurements acquired in the 23.8 GHz water vapor resonance band. For this reason, the Frequency Allocations in Remote Sensing (FARS) Technical Committee from the IEEE Geoscience and Remote Sensing Society (GRSS) has procured the development of a RFI monitoring payload to detect possible interferences in the 24 to 25 GHz band. This payload is compatible with the PocketQubes being developed in the framework of the "IEEE GRSS Open PocketQube Kit" educational initiative, and it will be used to measure and determine the occurrence of possible interferences close to the 23.8 GHz water vapor band. This work presents the design, implementation and testing of the 24 to 25 GHz RFI monitoring payload designed for a 1P PocketQube., This work was sponsored by the Frequency Allocations in Remote Sensing (FARS) Technical Committee of the IEEE Geoscience and Remote Sensing Society (GRSS). This project was also sposored in part by the project ”GENESIS: GNSS Environmental and Societal Missions – Subproject UPC”, Grant PID2021-126436OB-C21 funded by the Ministerio de Ciencia e Investigación (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 and EU FEDER “Una manera de hacer Europa”., Peer Reviewed, Postprint (author's final draft)

The Remote sensing and Interference detector with radiome-Try and vegetation Analysis (RITA Payload) [1] is a development of the UPC NanoSat Lab, aimed at Earth Observation (EO). It is one of the winners of the Second IEEE GRSS Student Grand Challenge, and will fly on-board AlainSat-1, a 3U CubeSat developed by the National Space Science and Technology Center (NSSTC) of the United Arab Emirates.RITA hosts three experiments. An L-band microwave radiometer (MWR) will gather data of soil moisture and sea ice thickness and concentration, aided with a Radio-frequency Interference (RFI) detection algorithm. A LoRa transceiver will perform on-demand execution of the EO experiments [2]. Finally, a Near-Infrared (NIR) Hyperspectral Camera will gather data for vegetation monitoring, agriculture applications, hydrology and coastal and inland waters mapping, among others [3].This work is focused on the calibration and validation of the Hyperspectral imager, at optical, electronic and spectral levels, as well as in the verification of its performance to measure Normalized Difference Vegetation Index (NDVI)., This project is supported and funded by the IEEE Geoscience and Remote Sensing Society (GRSS), as one of the winners of the 2nd IEEE GRSS Student Grand Challenge. It is also part of the project ”GENESIS: GNSS Environmental and Societal Missions – Subproject UPC”, Grant PID2021-126436OB-C21 funded by the Ministerio de Ciencia e Investigación (MCIN) / Agencia Estatal de Investigación (AEI) / 10.13039/501100011033 and EU FEDER “Una manera de hacer Europa., Peer Reviewed, Postprint (author's final draft)

The aim of this final thesis is to carry out the CAD design and structural analysis of: the support of the camera, the support for the rotor of the camera and a Magnetorquer, the whole set on board the 3Cat8 mission, corresponding to one of the missions of the UPC NanoSat Lab. The 3Cat8 mission the following main objectives. Firstly, the educational component, a project carried out by students, with the help of certain companies in the sector. Secondly, the scientific component, focused on the observation of the ionosphere using GNSS-RO. The elaboration of the design of the different components has been carried out through the design software respecting the standard dimensions of the CubeSat, comprised in a maximum available space and respecting the restrictions imposed by components of the neighbouring units. Subsequently, the model has been simplified in order to be able to replicate the structural behaviour of the components by optimising the computational calculations for FEM simulations. Once the model has been simplified, a series of analyses of modal type, random vibrations, quasi-static creep and shocks in the FEM type environment have been carried out. Finally, the results obtained, the are analyzed to get the conclusions. The achieved results are considered successful. Finally, a series of recommendation are made for the projects evolution.

This final degree thesis describes the development and implementation of an ADCS simulator for the 3Cat-8 mission of the UPC NanoSat Lab, which enables the calculation of the actuators and controller variables. Additionally, based on the ADCS simulator, specially focuses on the ATHENA ionic thruster control analysis ensuring the proper ADCS actuators sizing of the spacecraft. The control is solely achieved by magnetic actuators. It is shown that the satellite can maintain the desired orientation with low angular rates, required during the orbital raising maneuver. A new configuration of the control stability with linear attitude dynamics for satellite thruster, based on a control algorithm using attitude quaternion and angular velocity feedback is also described. To conclude, the presented numerical results prove the efficiency of the applied method based on initial theoretical considerations and the design measurements of the satellite and the thruster.

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

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.

The objective of this project is twofold. Firstly, a detailed research of the rocket has to be done in order to create a 3D CAD design of its structure. Secondly, the student will need to sketch the 1:50 scale plans necessary to assemble a model of the rocket., In this study, it is intended to analyse the Saturn V’s structure. Once this is done, a 1:50 3D model of the rocket will be designed, trying to be faithful to the original, but also having in mind that the model should be able to be manufactured. From the 3D version, a real-life model will be crafted and assembled as the final objective of this project.