author = "Venditti, F. C. F. and Rocco, Evandro Marconi",
          affiliation = "Planetary Radar, Arecibo Observatory and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "Modeling asteroids to assist in orbiting and landing missions",
              journal = "Advances in the Astronautical Sciences",
                 year = "2018",
               volume = "162",
                pages = "2041--2060",
                 note = "AAS/AIAA Astrodynamics Specialist Conference, 2017; Stevenson; 
                         United States; 20 August 2017 through 24 August 2017",
             abstract = "Asteroids are rotating bodies with asymmetric distribution of 
                         mass, which makes the gravitational field around them different 
                         from spherical bodies. In order to more accurately study the 
                         gravitational field around these objects, it is necessary to have 
                         a physical model. To simplify the model of an asteroid, it is 
                         common to use approximations to simple shapes such as ellipsoids. 
                         However, this may lead to an imprecise model, especially when the 
                         asteroid has a very asymmetric shape. Thus, a new methodology 
                         developed to model the gravitational field of the asteroids is 
                         presented, called Mascon-layer model. It consists in using a 
                         polyhedron shape model, which is built using observational data, 
                         thus giving a good approximation of the real shape of the object. 
                         This shape model is then transformed into layers of mass 
                         concentrations. The gravitational potential is obtained using the 
                         new model, and then applied to analyze very close orbits on the 
                         collision boundary, and very distant orbits on the verge of 
                         escaping the sphere of influence of the asteroid's gravitational 
                         field. Orbital maneuvers, using continuous low thrust in closed 
                         loop, were also performed. One of the advantages of the 
                         methodology developed is that it is possible to use a simpler 
                         approach, requiring less computational effort, but still using a 
                         reliable source for the shape model.",
                 issn = "0065-3438.",
             language = "en",
        urlaccessdate = "04 dez. 2020"