In this thesis, a simulation harness is constructed in Simulink for the purpose of validating the Attitude Determination and Control System (ADCS) on the APTAS student CubeSat in support of the upcoming flight readiness review. The simulation results are used to verify the compliance of a subset of the requirements for the ADCS, detailed in table 1. Calibration of the onboard sun sensor array, which is used to find the sun vector for the attitude determination, is performed using a break-out board of sun sensors tested in a sun simulator. The data gathered from this test is used to model the sun sensor system in the simulation and in flight software. The results show that the sun sensor system is able to find the sun vector with an average error angle of 5.4 degrees, though the error angle may spike up to 18 degrees in operation. It is found that the complete ADCS is able to guide the spacecraft toward the desired nadir-facing attitude, though not with the accuracy specified in the requirements. The spacecraft is able to detumble much better than required. All deficiencies found in the ADCS software have been corrected. These changes arelisted in appendix B. It is concluded that, despite its flaws, the ADCS software is flight ready. / Project APTAS

Since 2003, when the first batch of academic Cubesats was launched, 463 of these satellites havereached orbit. The issues faced in the early years were documented and since then the marketof Commercial off-the-shelf components, launch brokers and other auxiliary companies hassky-rocketed. Despite of the popularization of this educational satellites, or perhaps becauseof it, the rate of failures in this type of Cubesats kept constant over the years.The first part of this thesis explores the issues associated with development of academiccubesats found in literature, as well as the good practices and recommendations given by theteams. The studied works are divided in periods in order to examine possible trends in thetypes of issues and good practices reported.The document continues with an introduction to new paradigms and methodologies for ProjectManagement and Systems Engineering, paying special attention to Agile methodologies andMBSE and how they are, or could be applied, to academic Cubesat projects to mitigate thecommon issues and implement good practices.The use case of Cubesat for Radiation Environment Monitoring Experiment, the project wherethe author did his Master’s internship, is used to introduce the Time and Space Partitioningarchitecture in embedded systems, a very interesting approach that provides more reliabilitythan usual approaches and some project management benefits.Finally the use case of APTAS, another academic Cubesat project where the author wasinvolved, is used to illustrate how the issues and good practices mentioned in the first sectionaffect projects. This is achieved by extracting metrics about student engagement, turnoverratios and a thorough examination of the internal resources of the project.

Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-05T20:50:38Z No. of bitstreams: 1 DISS_2014_Joab Almeida da Silva.pdf: 3033730 bytes, checksum: 4a0f1680715be7f6554110dafd84ae3e (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-23T16:57:12Z (GMT) No. of bitstreams: 1 DISS_2014_Joab Almeida da Silva.pdf: 3033730 bytes, checksum: 4a0f1680715be7f6554110dafd84ae3e (MD5) / Made available in DSpace on 2018-04-23T16:57:12Z (GMT). No. of bitstreams: 1 DISS_2014_Joab Almeida da Silva.pdf: 3033730 bytes, checksum: 4a0f1680715be7f6554110dafd84ae3e (MD5) Previous issue date: 2014-11-04 / O lodo de esgoto é um resíduo perigoso de acordo com a NBR 10.004/04, e quando mal gerenciado, pode afetar de modo adverso não apenas o meio ambiente como a saúde pública, por ser agente de propagação de doenças. Por outro lado, o biossólido obtido a partir do lodo de esgoto doméstico é considerado um ótimo biofertilizante devido à sua composição, por ser rico em matéria orgânica, nitrogênio e fósforo. Este trabalho teve como objetivo avaliar o potencial do lodo oriundo de fossas/tanques sépticos domiciliares da Região Metropolitana de Cuiabá (RMC) para disposição final em solos agrícolas. O experimento de leito de secagem natural foi desenvolvido em um laboratório terceirizado com o objetivo de avaliar a qualidade do lodo coletado em fossas sépticas dos bairros Dom Aquino, Coxipó da Ponte, Morada da Serra, Boa Esperança e Jardim Universitário e lodo transportado por veículos limpa-fossa. O experimento seguiu o mesmo procedimento de tratamento do lodo nas estações de tratamento de esgoto. Após esse processo, o material foi higienizado com cal virgem a 50% da base seca e submetido a um período de maturação de 30 dias, posteriormente foram submetidas a análises laboratoriais. Os parâmetros analisados foram com relação à estabilidade, a metais pesados e organismos patogênicos resistentes. Os resultados foram comparados com os padrões da legislação vigente. Também foram utilizadas técnicas de geoprocessamento e sistemas de informações geográficas (SIG) com objetivo de identificar as áreas potencialmente aptas para recebimento de biossólido. De acordo com os resultados obtidos, o leito de secagem de exposição natural apresentou eficiência na desidratação e estabilização do lodo, atingindo níveis menores que 10% de umidade e a relação entre sólidos voláteis e totais menores que 0,10; com relação às concentrações de elementos-traços de metais analisadas, todas as amostras de biossólidos apresentaram teores inferiores aos valores máximos permitidos pela Resolução CONAMA 375/06, inclusive a amostra do caminhão limpa-fossa, que apresentou os teores mais elevados dos parâmetros analisados; após a higienização do lodo, o material apresentou qualidade de biossólido classe A em relação à concentração de organismos patogênicos; por fim, o estudo do meio físico viabilizou a disposição do biossólido em pelo menos 75,30% (2.664,23 km²) da área do município, enquanto que 24,70% (873,93km²) apresentam restrições por se tratar de locais não recomendados para à aplicação desse tipo de material. / The sewage sludge is a hazardous waste according to NBR 10004/04, and when poorly managed, can adversely affect not only the environment and public health, to be the spread of disease agent. On the other hand, the sludge obtained from the sewage sludge is considered a great biofertilizer due to its composition, to be rich in organic matter nitrogen and phosphorus. This study aimed to evaluate the potential of the sludge coming from tanks / household septic tanks in the metropolitan region of Cuiabá (RMC) for final disposal on agricultural soils. The experiment of natural drying bed was developed in an outsourced laboratory with the aim of evaluating the quality of the sludge collected in pits neighborhoods Dom Aquino, Coxipó da Ponte, Morada da Serra, Boa Esperança and Jardim Universitário of septic tanks and transported by vehicles clean-pit. The experiment followed the same procedure in the treatment of sludge from sewage treatment plants. After this process, the material was sanitized with quicklime to 50% dry basis and undergo a maturation period of 30 days, then were subjected to laboratory analysis. The parameters were analyzed with respect to stability, the trace elements of metals and resistant pathogens. The results were compared with the current legislation standards. GIS techniques and geographic information systems (GIS) in order to identify potentially suitable for areas receiving biosolids were also used. According to the results, the drying bed natural exposure showed efficiency in dewatering and sludge stabilization, reaching levels lower than 10% humidity, the ratio between volatile and less than 0.10 total solids; with respect to the concentrations of trace elements of metals analyzed, all samples showed lower levels of biosolids to the maximum values allowed by CONAMA Resolution 375/06, including sample clean-truck fossa, which showed the highest levels of the analyzed parameters; after cleaning the sludge, the material presented quality Class A biosolids in relation to the concentration of pathogenic organisms; Finally, the study of the physical environment facilitated the disposal of biosolids at least 75.30% (2664.23 km ²) of the municipal area, while 24.70% (873,93km²) have restrictions because it is not local recommended for the application of this type of material.