author = "Almeida J{\'u}nior, Allan Kardec de and Prado, Antonio Fernando 
                         Bertachini de Almeida and Yokoyama, Tadashi and Merguizo Sanchez, 
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Estadual 
                         Paulista (UNESP)} and {Instituto Nacional de Pesquisas Espaciais 
                title = "Searching for orbits to observe the poles of celestial bodies",
              journal = "Advances in Space Research",
                 year = "2020",
               volume = "66",
               number = "10",
                pages = "2378--2401",
                month = "Nov.",
             keywords = "Astrodynamics, Nonlinear systems, Artificial equilibrium points, 
                         Restricted three-body problem.",
             abstract = "The objective of the present paper is to show a method to find 
                         orbits near artificial equilibrium points for a satellite equipped 
                         with a continuous thrust that allows it to stay near the poles of 
                         a celestial body. The physical system includes the presence of a 
                         moon of the celestial body under observation, and the perturbation 
                         caused by this moon is counteracted by an algorithm to help the 
                         satellite to stay close to its original position, instead of 
                         escape from it. The equations of motion are changed under some 
                         approximations, and analytical solutions for these equations are 
                         obtained and analyzed. Initial conditions are used such that their 
                         secular terms are nullified. These solutions are restricted to a 
                         short period of time, but we propose a method in which there are 
                         periodic updates in the thrust. Thus, the solutions can be 
                         extended for the duration of the mission. A numerical simulation 
                         is obtained, whose results are required to be in agreement with 
                         the analytical solution using these periodic adjustments of the 
                         thrust. This agreement means that the motion of the spacecraft 
                         remains bounded close to its initial position for longer times. 
                         Several systems with different sizes and mass parameters are used 
                         to show the results of the research, like Sun-Earth-Moon, 
                         Sun-Ida-Dactyl, Sun-Saturn-Titan and Sun-Mars-Phobos systems. The 
                         results also indicate the locations of points that require minimum 
                         magnitude of the thrust.",
                  doi = "10.1016/j.asr.2020.07.043",
                  url = "http://dx.doi.org/10.1016/j.asr.2020.07.043",
                 issn = "0273-1177 and 1879-1948",
             language = "en",
           targetfile = "almeida junior_searching.pdf",
        urlaccessdate = "19 abr. 2021"