Study of low-thrust orbital maneuvers in the presence of external disturbing forces

• Autor(a) principal: Thais Carneiro Oliveira
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações do INPE
• Texto Completo: http://urlib.net/sid.inpe.br/mtc-m21b/2016/04.18.14.16

One of the main objectives of this thesis is to study the magnitude of the disturbing forces received by a spacecraft for several orbits with the help of the method called Perturbation Integral. The Perturbation Integral can be the integral of the magnitude of the acceleration caused by the external disturbing forces that act on a spacecraft for one orbital period or the magnitude of the integral of the acceleration of the external disturbing forces for one orbital period. The study includes the behavior of different external disturbing forces for different orbits by varying the Keplerian elements. In this context, it is possible to find orbits that are less perturbed and create maps for various orbits that illustrate the magnitude of the perturbation behavior and the fuel consumption required to keep a spacecraft in a Keplerian orbit and the fuel consumptions required to perform orbital maneuvers after a period of time. Another main objective is to study low-thrust orbital maneuvers, known as station-keeping maneuvers, and to reduce the fuel consumption that may be used in the thrusters. The orbit of a spacecraft is deviated from the Keplerian orbit due to external perturbations. Propulsions systems can be used to correct the orbit with fuel expenditure. One of the proposals of this thesis is the use of electrodynamic tethers and solar sails to reduce the effects of the external perturbations to reduce the fuel consumption in station-keeping maneuvers. This study also includes the possibility to use the electrodynamic tethers as a drag force to optimize the time of the orbital decay of a spacecraft. The validation of the tether or solar sail usage is performed in two different environments. The first one is an orbital integrator that integrates the orbit of the spacecraft including the external disturbing forces. The second environment, used only for the solar sail validation, is an orbit simulator that can include a more realistic environment, like failures on the actuators, on the sensors, external disturbing forces non-predicted, etc. This last simulator is known as 'STRS' or "Spacecraft Trajectory Simulator".