Results of the attitude reconstruction for the UniSat-6 microsatellite using in-orbit data

UniSat-6 is a civilian microsatellite that was launched in orbit on the 19th of June, 2014. Its main mission consisted in the in-orbit release of a number of on-board carried Cubesats and in the transmission to the UniSat-6 ground station of telemetry data and images from an on-board mounted camera. The spacecraft is equipped with a passive magnetic attitude control system. Gyros and magnetometers provide the information about the attitude of the spacecraft. The importance of reconstructing the attitude motion of UniSat-6 lies in the dual possibility, for future missions, of:controlling the direction of ejection of the on-board carried satelliteshaving an accurate pointing for remote sensing operation.The reconstruction of the attitude motion of UniSat-6 is based on the data of the on-board Commercial Off The Shelf (COTS) gyros and magnetometers, downloaded at the passages over the ground station in Roma, Italy. At ground, these data have been processed with the UnScented QUaternion Estimator (USQUE) algorithm. This estimator is an adaptation of the Unscented Filter to the problem of spacecraft attitude estimation. The USQUE is based on a dual attitude representation, which involves both quaternions and Generalized Rodrigues Parameters. In this work, the propagation phase of the algorithm contains only a kinematic model of the motion of the spacecraft. This paper presents the results of the reconstruction of the UniSat-6 attitude using on-board measurements. The results show that the spacecraft effectively stabilized its attitude motion thanks to the on-board magnetic devices

The Suaineadh Project : a stepping stone towards the deployment of large flexible structures in space

The Suaineadh project aims at testing the controlled deployment and stabilization of space web. The deployment system is based on a simple yet ingenious control of the centrifugal force that will pull each of the four daughters sections apart. The four daughters are attached onto the four corners of a square web, and will be released from their initial stowed configuration attached to a central hub. Enclosed in the central hub is a specifically designed spinning reaction wheel that controls the rotational speed with a closed loop control fed by measurements from an onboard inertial measurement sensor. Five other such sensors located within the web and central hub provide information on the surface curvature of the web, and progression of the deployment. Suaineadh is currently at an advanced stage of development: all the components are manufactured with the subsystems integrated and are presently awaiting full integration and testing. This paper will present the current status of the Suaineadh project and the results of the most recent set of tests. In particular, the paper will cover the overall mechanical design of the system, the electrical and sensor assemblies, the communication and power systems and the spinning wheel with its control system

Design of a flatsat for the AlbaSat mission

openThis thesis presents the design of a FlatSat for the AlbaSat mission. AlbaSat is a 2U CubeSat with four mission objectives: (1) to collect in-situ measurements of the sub-mm space debris environment in LEO, (2) to study the micro-vibration environment on the satellite throughout different mission phases, (3) to do orbit and attitude determination through laser ranging; (4) to investigate alternative systems for possible Satellite Quantum Communication applications on nanosatellites. Firstly, an overview of CubeSats state of art and of the AlbaSat mission is provided, illustrating the main mission objectives and the importance of testing and verifying the satellite performance before launch using, for instance, FlatSat. Subsequently, the objectives of the FlatSat in the AlbaSat mission are defined. These objectives include creating a test and verification platform to evaluate the satellite's functionalities, verifying the proper interaction between subsystems, and achieving performance and reliability requirements. The design of the FlatSat is described in detail, including component selection, functional architecture, subsystem arrangement, and interfaces between them. Aspects such as power supply, attitude control, data acquisition, and communication are considered. Special attention is given to subsystem integration to ensure proper connection and interaction. The tests programmed on the FlatSat are presented, including functional tests, integration tests, and communication tests. In addition, the Electro-magnetic Compatibility (EMC) of the satellite components is addressed. Aspects related to electromagnetic interference and protective measures are analyzed to ensure immunity to external electromagnetic disturbances and non-interference with other systems or devices. The thesis is developed in the framework of the Alba CubeSat project, which participate to the European Space Agency’s (ESA) Fly Your Satellite! – design booster program. The thesis provides the guidelines to assembly and integrate and test the FlatSat of AlbaSat, contributing to the development of the mission. The results and experiences gained from this research can be applied to future satellite development projects

Design and implementation of a single On-Board Computer for CubeSats

his document reports the process of design, implementation, and testing of an On-Board Computer for CubeSats in a single 1U-sized CubeSat PCB. The aim is to design a modular, cheap, e cient and exible product than could be easily reproduced and implemented in forthcoming CubeSats missions. The document describes all the hardware design phases, from the selection of components to the creation of the circuits and blocks, following with the physical design of the layout in two stackable boards, and nally the actual integration and subsequent electrical test of the components. The project ended successfully with a prototype of the OBC allowing the boot of a Linux operative system from a µSD card, and the documentation needed to reproduce the work and manufacture new products

Design of MECSE Nanosatellite Mechanical Subsystem

Magnetohydrodynamics/Electrohydrodynamics CubeSat Experiment (MECSE) is the first Cube- Sat being developed at the University of Beira Interior (UBI) and it is an under development Nanosatellite resulting from the collaboration between C-MAST (Center for Mechanical and Aerospace Science and Technologies) and CEiiA (Centre of Engineering and Product Development). MECSE’s mission is to create a benchmark for the future validation of the theory that an Electromagnetic field can re-shape the layer of plasma surrounding a spacecraft, and therefore allow communications during the so-called atmospheric re-entry Radio Frequency (RF) blackout phase. When it comes to scientific space research there is a need to create a bridge between the scientific goals and the engineering feasibility. In order for the mission to take shape, the development of the product CubeSat shall meet scientific requirements as well as production limitations and space regulations. This master dissertation aims to preliminarily develop MECSE’s Mechanical Subsystem. In this work, a Mechanical Subsystem configuration that ensures the structural reliability during launch, as well as on orbit was developed. The approach adopted for the design of MECSE’s Mechanical System was to, first, define the different project requirements, and then, COTS hardware components were selected based on similar previous missions and their requirements were specified. The project also presents Design Requirements that were specified based on the CubeSat Design Specifications, and the launch platform P-POD. Finally, the materials for the primary structure of the CubeSat had to be selected. A trade-off was performed comparing several material properties (e.g. thermal conductivity, electrical conductivity, workability and others) and the aluminum alloy 7075 T6 was chosen. The spacecraft must sustain a set of mechanical loads without permanent deformation, with a certain margin of safety to prevent the uncertainties in the loading values during launch. A finite element analysis validated the capacity of MECSE to sustain the linear static loads and static temperature during launch and on-orbit.The components were evaluated and, with exception of the Side Frames, the primary structural components should have their thickness reduced, since they presented high margins of safety to stress and strain. The thermal impact study showed that the subsystems will have their envelope of operations conditioned by the angle between the orbit plane and the solar vector. In order to increase the envelop of operations it was recommended the use of aerogel.Magnetohydrodynamics/Electrohydrodynamics CubeSat Experiment (MECSE) é o primeiro Cube- Sat a ser desenvolvido na Universidade da Beira Interior (UBI), resultando da colaboração do C-MAST (Centro de Ciências e Tecnologia Mecânica e Aeroespacial) e o CEiiA (Centro de Engenharia e Desenvolvimento de Produto). A missão do MECSE é criar uma plataforma para a futura validação da teoria que afirma que um campo electromagnético permite diminuir a espessura da camada de plasma e, como tal, permitir comunicações durante a reentrada atmosférica, evitando a chamada fase de blackout. De modo a dar forma à missão, foi necessário o desenvolvimento do produto CubeSat que respeite os requisitos ciêntificos bem como as limitações de produção e regulação espacial, promovendo assim a viabilidade técnica. Esta dissertação de mestrado tem como objectivo o desenvolvimento preliminar do Subsistema Mecânico do MECSE, cuja configuração assegura a fiabilidade estrutural durante o lançamento e em órbita. A abordagem adotada para o design do Subsistema Mecânico do MECSE foi a de primeiro definir os diferentes requisitos de projeto. Depois da definição dos subsistemas necessários, os componentes e respectivos requisitos de hardware foram escolhidos com base em missões semelhantes. O projeto também apresenta requisitos de design que foram estabelecidos tendo por base as especificações de design de Cubesats e as especificações da plataforma de lançamento P-POD. Depois da definição de requisitos, o material para a estrutura primária foi escolhido. Um estudo de trade-off foi realizado em que se comparou várias propriedades dos materiais (p.ex condutividade térmica, condutividade elétrica, maleabilidade, entre outros) e a liga de alumínium 7075 T6 foi a escolhida para a estrutura primária do MECSE. A aeronave deve resistir a um conjunto de cargas mecânicas sem deformar permanentemente com uma determinada margem de segurança devido às incertezas do valor associado às cargas durante o lançamento. Análises em elementos finitos validaram a capacidade do MECSE em resistir às cargas estáticas lineares e às temperaturas estáticas durante o lançamento e em órbita. Os componentes foram avaliados e foi concluído que todos os componentes com exceção das Side Frames deveriam ter a sua espessura reduzida, pois apresentavam uma margem de segurança alta para tensão e deformação. Um estudo de impacto térmico foi realizado e foi possível concluir que os subsistemas terão o seu envelope de operação condicionado pelo ângulo entre o plano de órbita e o vetor solar. De forma a aumentar o envelope de operações, é recomendada a aplicação de aerogel

DESIGN MODULAR COMMAND AND DATA HANDLING SUBSYSTEM HARDWARE ARCHITECTURES

Over the past few years, On-Board Computing Systems for satellites have been facing a limited level of modularity. Modularity is the ability to reuse and reconstruct the system from a set of predesigned units, with minimal additional engineering effort. CDHS hardware systems currently available have a limited ability to scale with mission needs. This thesis addresses the integration of smaller form factor CDHS modules used for nanosatellites with the larger counterparts that are used for larger missions. In particular, the thesis discusses the interfacing between Modular Computer Systems based on Open Standard commonly used in large spacecrafts and PC/104 used for nanosatellites. It also aims to create a set of layers that would represent a hardware library of COTS-like modules. At the beginning, a review of related and previous work has been done to identify the gaps in previous studies and understand more about Modular Computer Systems based on Open Standard commonly used in large spacecrafts, such as cPCI Serial Space and SpaceVPX. Next, the design requirements have been set to achieve this thesis objectives, which included conducting a prestudy of system alternatives before creating a modular CDHS hardware architecture which was later tested. After, the hardware suitable for this architecture based on the specified requirements was chosen and the PCB was designed based on global standards. Later, several functional tests and communication tests were conducted to assess the practicality of the proposed architecture. Finally, thermal vacuum testing was done on one of the architecture’s layers to test its ability to withstand the space environment, with the aim to perform the vibration testing of the full modular architecture in the future. The aim of this thesis has been achieved after going through several tests, comparing between interfaces, and understanding the process of interfacing between different levels of the CDHS. The findings of this study pave the way for future research in the field and offer valuable insights that could contribute to the development of modular architectures for other satellite subsystems

PyrSat - Prevention and response to wild fires with an intelligent Earth observation CubeSat

Forest fires are a pervasive and serious problem. Besides loss of life and extensive environmental damage, fires also result in substantial economic losses, not to mention property damage, injuries, displacements and hardships experienced by the affected citizens. This project proposes a low-cost intelligent hyperspectral 3U CubeSat for the production of fire risk and burnt area maps. It applies Machine Learning algorithms to autonomously process images and obtain final data products on-board the satellite for direct transmission to users on the ground. Used in combination with other services such as EFFIS or AFIS, the system could considerably reduce the extent and consequences of forest fires

LAICAnSat : uma plataforma experimental para balões de pequeno porte

Monografia (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2014.Este trabalho apresenta o desenvolvimento de uma plataforma de balão de alta altitude para aplicações em meteorologia e sensoriamento remoto. O LAICAnSat tem como objetivo obter dados para a identificação de camadas atmosféricas, assim como proporcionar imagens da superfície terrestre. Para isso, o sistema embarcado possui receptor GPS, sensor de temperatura, pressão, umidade, raios ultravioleta, infravermelho, câmera, assim como sensores de tensão e corrente, para housekeeping do sistema. É apresentado também uma revisão bibliográfica, resumindo as principais atividades de balões de alta altitude no mundo e os projetos já desenvolvidos no Brasil. Por fim, são apresentadas diversas perspectivas de evolução para o projeto LAICAnSat. A contribuição desse projeto é a solução das principais dificuldades que tangem o desenvolvimento inicial de balões de alta altitude, assim como o desenvolvimento de uma primeira plataforma, com uma arquitetura capaz de atender aos requisitos apresentados. Assim, o sistema foi testado em uma aeronave e depois lançado em dois balões de alta altitude.This work presents the development of a high altitude balloon platform with meteorology and remote sensing applications. The LAICAnSat main objective is to gather data about the atmosphere layers, as well as provide high altitude images. Therefore, this platform has a broad sensor suite, with GPS, temperature, pressure, humidity sensors, along with ultraviolet sensors, infrared sensors and camera. Also, some sensors are used for housekeeping as for instance the voltage and current monitors. Besides that, this work presents a review of the history behind high altitude balloon research and also the projects developed in Brazil regarding this activity. Nevertheless, future perspectives for the LAICAnSat project are highlighted. The solution for most of the difficulties that restrain the initial development of high altitude balloons is the expected contribution of this work, along with the development of the first high altitude balloon payload, addressing each of the assigned requirements

Avaliação do Uso de uma Rede Intra-Chip para Comunicação entre Processadores de Nanossatélites

TCC(graduação) - Universidade Federal de Santa Catarina. Campus Araranguá. Engenharia de Computação.Nanossatélites fazem parte de uma categoria de satélites artificiais com duas características importantes: tamanho reduzido e baixo custo de matéria prima para sua construção. Eles, normalmente, possuem entre quatro e cinco placas com eletrônica embarcada, as quais controlam to- das as suas funções. Uma alternativa para minimizar ainda mais seus custos é o desenvolvimento de um sistema intra-chip (também conhe- cido como System-on-Chip ou SoC), que pode utilizar um dispositivo lógico programável, tipo FPGA, de uso comercial (ou COTS, acrônimo do inglês Commercial Off-The-Shelf component). Para utilizar este tipo de dispositivo, é necessário acrescentar mecanismos que possam evitar problemas decorrentes da radiação cósmica que atinge os componentes eletrônicos, o que é comum no ambiente espacial por onde circulam os nanossatélites. Este trabalho apresenta a proposta de uma rede intra- chip que conecta até quatro processadores do tipo soft-core, formando um SoC. A rede, amparada pela técnica dos códigos de Hamming, ofe- rece mecanismos que permitem a ela seu restabelecimento de uma falha temporária dos tipos Single Event Upset e Single Event Transient. Esta proteção foi confirmada com simulações realizadas com um software que possibilita a injeção de falhas, denominado ModelSim. Resultados de menor consumo de silício, concomitante a economias no projeto e re- dução da sensibilidade à ionização cósmica, podem ser observados após os experimentos elaborados