@Article{SchmittPradSukhGome:2022:SwApEs,
               author = "Schmitt, Rodrigo Nascente and Prado, Antonio Fernando Bertachini 
                         de Almeida and Sukhanov, Alexander and Gomes, Vivian Martins",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Russian Academy of 
                         Sciences} and {Universidade Estadual Paulista (UNESP)}",
                title = "Swing-By Applications and Estimation of the Van Allen Belts’ 
                         Radiation Exposure for a Spacecraft in a Low Thrust Transfer to 
                         the Moon",
              journal = "Symmetry",
                 year = "2022",
               volume = "14",
               number = "3",
                pages = "e617",
                month = "Mar.",
             keywords = "astrodynamics, low thrust, mission analysis, swing-by, Van Allen 
                         belts.",
             abstract = "This paper presents a handful of the underlying properties of a 
                         spacecrafts transfer from a low Earth orbit (LEO) to the moons 
                         orbit using an electric propulsion (low-thrust) system. The use of 
                         analytical and numerical-analytical modeling in complex natural 
                         and technical processes is a key factor in this issue of Symmetry, 
                         which has been thoroughly explored in this paper. First, an 
                         optimization problem was considered to find the locations and 
                         lengths of the thrust arcs that maximizes the final mass of the 
                         spacecraft for a number of transfer orbits, thereby limiting the 
                         scope of trajectories to the most fuel-efficient ones. In addition 
                         to this, the Van Allen belts were modelled according to the 
                         density of electrons and protons in each point of space, in order 
                         to measure the total radiation absorbed by the spacecraft through 
                         an integration of the density of particles over the corresponding 
                         time. The simulations were then able to predict the relationship 
                         between the fluence of the particles and several initial 
                         parameters, such as the initial orbits eccentricity and the 
                         propulsion systems characteristics. Then, a multi-linear 
                         regression and an artificial neural network were fitted to the 
                         data through a regression that related the fluence of protons and 
                         electrons as a function of the following parameters: mission time, 
                         specific impulse, thrust, final mass (i.e., propellant 
                         consumption) and the initial height of the perigee, eccentricity 
                         and inclination. This analysis was proven to be powerful due to 
                         the expressive values from statistical tests, showing underlying 
                         positive correlations between thrust, mission time and final 
                         spacecraft mass with the fluence of particles, and negative 
                         correlations between specific impulse, initial orbit eccentricity, 
                         inclination and the height of the perigee with the fluence of 
                         particles. Finally, an analysis of a swing-by maneuver was also 
                         carried out, together with the radiation incidence, revealing 
                         hidden dependencies of the increments in energy and velocity with 
                         respect to the fuel consumption, radiation absorption, propulsion 
                         system and initial orbit parameters.",
                  doi = "10.3390/sym14030617",
                  url = "http://dx.doi.org/10.3390/sym14030617",
                 issn = "2073-8994",
             language = "en",
           targetfile = "symmetry-14-00617-v3.pdf",
        urlaccessdate = "04 maio 2024"
}