author = "Aljbaae, Safwan and Merguizo Sanchez, Diogo and Prado, Antonio 
                         Fernando Bertachini de Almeida and Souchay, Jean and Terra, Maisa 
                         O. and Negri, Rodolfo Batista and Marchi, Luis Ot{\'a}vio",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Universit{\`e} Paris} and 
                         {Instituto Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "First approximation for spacecraft motion relative to (99942) 
              journal = "Romanian Astronomical Journal",
                 year = "2021",
               volume = "31",
               number = "3",
                pages = "241--263",
             keywords = "Celestial MechanicsDynamical astronomyMinor planetsasteroids: 
                         individual (Apophis).",
             abstract = "We aim at providing a preliminary approach on the dynamics of a 
                         spacecraft in orbit about the asteroid (99942) Apophis during its 
                         Earth close approach. The physical properties from the polyhedral 
                         shape of the target are derived by assigning each tetrahedron to a 
                         point mass in its center. That considerably reduces the 
                         computation processing time compared to previous methods to 
                         evaluate the gravitational potential. The surfaces of section 
                         close to Apophis are build considering or not the gravitational 
                         perturbations of the Sun, the planets, and the SRP. The Earth is 
                         the one that most affects the investigated region making the vast 
                         majority of the orbits collide or escape from the system. 
                         Moreover, from numerical analysis of orbits started on March 1, 
                         2029, the less perturbed region is characterized by the variation 
                         of the semimajor axis of 40-day orbits, which do not exceed 2 km 
                         very close to the central body (a < 4 km, e < 0.4). However, no 
                         regions investigated could be a possible option for inserting a 
                         spacecraft into natural orbits around Apophis during the close 
                         approach with our planet. Finally, to solve the stabilization 
                         problem in the system, we apply a robust path following control 
                         law to control the orbital geometry of a spacecraft. At last, we 
                         present an example of a successful operation of our orbit control 
                         with a total Delta v of 0.495 m/s for 60 days. All our results are 
                         gathered in the CPM-ASTEROID database, which will be regularly 
                         updated by considering other asteroids.",
                 issn = "{1220-5168;} and 2285-3758",
             language = "en",
        urlaccessdate = "2021, Dec. 04"