Fechar
Metadados

@PhDThesis{Silva:2017:EsMiEs,
               author = "Silva, Maria Rita da",
                title = "Estudo de uma miss{\~a}o espacial aos pontos colineares 
                         lagrangianos no sistema Terra-Lua",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2017",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2017-06-30",
             keywords = "pontos de equil{\'{\i}}brio lagrangianos, sistema Terra-Lua, 
                         cintur{\~o}es de radia{\c{c}}{\~a}o de Van Allen, 
                         transfer{\^e}ncia de {\'o}rbitas, manobra orbitais, Lagrangian 
                         equilibrium points, Earth-Moon system, Van Allen radiation belts, 
                         transfer orbits, orbital maneuvers.",
             abstract = "Em um sistema planeta-lua-ve{\'{\i}}culo espacial existem cinco 
                         pontos de equil{\'{\i}}brio, sendo que tr{\^e}s s{\~a}o 
                         inst{\'a}veis (L1, L2, L3) e dois s{\~a}o est{\'a}veis (L4, 
                         L5). Estes pontos s{\~a}o alvos constantes das 
                         perturba{\c{c}}{\~o}es externas gravitacionais e 
                         n{\~a}o-gravitacionais, que podem inviabilizar a 
                         utiliza{\c{c}}{\~a}o dos mesmos em miss{\~o}es espaciais para 
                         observar o Universo e o nosso Sistema Solar. Deste modo, neste 
                         trabalho, objetiva-se estudar e analisar as manobras orbitais de 
                         um ve{\'{\i}}culo espacial utilizando propuls{\~a}o 
                         cont{\'{\i}}nua, controladas por um sistema de controle PID em 
                         malha fechada, a partir de uma {\'o}rbita de baixa altitude, em 
                         torno da Terra, para cada um dos tr{\^e}s pontos colineares 
                         lagrangianos do sistema Terra-Lua considerando as 
                         perturba{\c{c}}{\~o}es externas como efeito durante as manobras 
                         orbitais. Assim, primeiramente, modelou-se os cintur{\~o}es de 
                         radia{\c{c}}{\~a}o utilizando os dados fornecidos pela 
                         miss{\~a}o Van Allen Probes. Em seguida, determinou-se as 
                         localiza{\c{c}}{\~o}es dos pontos colineares lagrangianos por 
                         meio do somat{\'o}rio das atra{\c{c}}{\~o}es gravitacionais da 
                         Terra e da Lua, a cada instante de tempo, compensadas com a 
                         pseudo-for{\c{c}}a centr{\'{\i}}fuga, em um referencial 
                         n{\~a}o-inercial; logo ap{\'o}s, determinou-se o mesmo, 
                         por{\'e}m sob a influ{\^e}ncia da atra{\c{c}}{\~a}o 
                         gravitacional do Sol, da press{\~a}o de radia{\c{c}}{\~a}o 
                         solar e do potencial gravitacional dos corpos prim{\'a}rios 
                         n{\~a}o-esf{\'e}ricos. A partir destas localiza{\c{c}}{\~o}es 
                         instant{\^a}neas, obteve-se os elementos de estado 
                         instant{\^a}neos que foram transformados em elementos orbitais 
                         instant{\^a}neos, o que resultou na identifica{\c{c}}{\~a}o das 
                         pseudo-{\'o}rbitas dos pontos colineares lagrangianos, no 
                         referencial inercial. Desta forma, iniciou-se as 
                         simula{\c{c}}{\~o}es, sendo que, primeiramente, incluiu-se um 
                         estudo sobre a passagem do ve{\'{\i}}culo espacial atrav{\'e}s 
                         dos cintur{\~o}es de Van Allen, durante as manobras de 
                         transfer{\^e}ncia, nos per{\'{\i}}odos de baixa e alta 
                         atividade solar. Isto possibilitou obter, com maior precis{\~a}o, 
                         o tempo que o ve{\'{\i}}culo espacial permaneceu nas 
                         regi{\~o}es de radia{\c{c}}{\~a}o e a taxa de dosagem de 
                         radia{\c{c}}{\~a}o equivalente considerando o alum{\'{\i}}nio, 
                         sil{\'{\i}}cio, tungst{\^e}nio, t{\^a}ntalo e chumbo como 
                         materiais de blindagem. Ap{\'o}s as manobras de 
                         transfer{\^e}ncia, aplicou-se a manobra de corre{\c{c}}{\~a}o 
                         de {\'o}rbita para estabilizar o ve{\'{\i}}culo espacial em 
                         cada um dos pontos colineares lagrangianos. ABSTRACT: In a 
                         planet-moon-space-vehicle system there are five equilibrium 
                         points, being that three are unstable (L1, L2, L3), and two are 
                         stable (L4, L5). These points are targets of external 
                         gravitational and non-gravitational perturbations, which may make 
                         it impossible to use them in space missions to observe the 
                         Universe and our Solar System. So, in this work, the objective is 
                         to study and analyze the orbital maneuvers of a space vehicle 
                         using continuous propulsion, controlled by a closed-loop PID 
                         control system, from a low altitude orbit, around the Earth, for 
                         each one of the three collinear Lagrangian points in the 
                         Earth-Moon system considering the external perturbations as effect 
                         during the orbital maneuvers. Thereby, the radiation belts were 
                         first modeled using the data provided by the Van Allen Probes 
                         mission. Next, the locations of the collinear Lagrangian points 
                         were determined by sum of the Earths and Moons gravitational 
                         attractions, at each instant of time, compensated by the 
                         centrifugal pseudo-force, in a noninertial frame; subsequently, 
                         they were determined, but under the influence of the gravitational 
                         attraction of the Sun, the solar radiation pressure and the 
                         gravitational potential of the non-spherical primary bodies. From 
                         these instantaneous locations, the instantaneous state elements 
                         were obtained and transformed into instantaneous orbital elements, 
                         which resulted in the identification of the pseudo-orbits of the 
                         collinear Lagrangian points, in the inertial reference frame. 
                         Therefore, the simulations were initiated. Firstly, a study was 
                         included on the passage of the space vehicle through the Van Allen 
                         belts, during the maneuvers of transfer, during periods of low and 
                         high solar activity. This made it possible to obtain, with more 
                         precision, the time the spacecraft remained in the radiation 
                         regions and the equivalent radiation dose rate considering 
                         aluminum, silicon, tungsten, tantalum and lead as shielding 
                         materials. After the maneuvers of transfer, the orbit correction 
                         maneuver was applied to stabilize the space vehicle at each of the 
                         collinear Lagrangian points.",
            committee = "Ricci, Mario Cesar (presidente) and Rocco, Evandro Marconi 
                         (orientador) and Moraes, Rodolpho Vilhena de and Carvalho, 
                         Francisco das Chagas and Costa Filho, Aguinaldo Cardozo da",
         englishtitle = "Study of a space mission to collinear Lagrange points in the 
                         Earth-Moon system",
             language = "pt",
                pages = "249",
                  ibi = "8JMKD3MGP3W34P/3PDP29P",
                  url = "http://urlib.net/rep/8JMKD3MGP3W34P/3PDP29P",
           targetfile = "publicacao.pdf",
        urlaccessdate = "05 dez. 2020"
}


Fechar