Influence of perturbative forces in the motion of spacecraft: around artificial equilibrium points and in measurements of indices

• Ano de defesa: 2018
• Autor(a) principal: Allan Kardec de Almeida Junior
• Orientador(a): Diogo Merguizo Sanchez, Tadashi Yokoyama
• Banca de defesa: Vivian Martins Gomes, Rita de Cássia Domingos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Instituto Nacional de Pesquisas Espaciais (INPE)
• Programa de Pós-Graduação: Programa de Pós-Graduação do INPE em Mecânica Espacial e Controle
• País: BR
• Link de acesso: http://urlib.net/sid.inpe.br/mtc-m21c/2018/08.16.17.00

This thesis describes a research about the effects of perturbative forces over the motion of a spacecraft around artificial equilibrium points and over measurements of integral indices. In order to accomplish the task, an initial investigation about how the artificial equilibrium points are located in the space is done, whose results are applied to the Sun-Earth system and to a planar solar sail. Using this concept, solutions are proposed for a communication problem between a spacecraft located near the classical lagrangean point L3 and the Earth, due to the presence of the Sun. Moreover, analytical solutions are proposed to describe the motion of a spacecraft around artificial equilibrium points, whose results are applied to a spacecraft located near L3 in the Sun-Earth system perturbed by the gravity of Jupiter and Venus, to be compared with numerical integrations of the equations of motion. Such kind of analytical solutions are extended to a spacecraft located above/below a massive body that rotates with another massive body around their barycenter, perturbed by a general moon. This last kind of solution involves periodic corrections of the thrust applied over the spacecraft. The results show that the analytical solution comes closer to the numerical integration of the equations of motion when the frequency of the corrections is higher. The influence of perturbative forces over integral indices is also investigated in this thesis. Initially, they are defined analogously to the ones known in the literature and they are evaluated using the driven harmonic, Duffing, and Van der Pol oscillators, which may represent perturbative models of the simple harmonic oscillator. Thus, this research is extended to a more realistic astrodynamic case of a spacecraft moving around a massive body (the Earth) subjected to a thrust in the tangential and radial directions. New indices are defined and evaluated using a perturbative solution for a low, constant and radial thrust. Thus, an index is identified as capable of describe interesting perturbative effects over the motion.