Josué Cardoso Dos Santos | Universidade Estadual Paulista "Júlio de Mesquita Filho" (original) (raw)
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Papers by Josué Cardoso Dos Santos
In this paper, a search for low-altitude orbits around Europa is performed. An emphasis is given ... more In this paper, a search for low-altitude orbits around Europa is performed. An emphasis is given in frozen orbits. These orbits are used in the planning of aerospace activities to be conducted around this planetary satellite, with respect to the stability of orbits of artificial satellites. The study considers orbits of artificial satellites around Europa under the influence of the third-body perturbation (the gravitational attraction of Jupiter) and the polygenic perturbations. These last ones occur due to forces such as the non-uniform distribution of mass (J2 and J3) of the main (central) body. A simplified dynamic model for these perturbations is used. The
Lagrange planetary equations, which compose a system of nonlinear differential equations, are used to describe the orbital motion of the artificial satellite around Europa. The equations of motion are developed in closed form to avoid expansions in power series. Low-altitude polar orbits and frozen orbits with long lifetimes were found. This study can be used for planning of future space missions which seek to visit Europa and other planetary satellites.
Nowadays, there are several studies for missions that will place a satellite around Europa. There... more Nowadays, there are several studies for missions that will place a satellite around Europa. There are many important aspects that deserve to be studied in this natural satellite of Jupiter. It makes the study of orbits around Europa a particular important part of the mission, since a good choice for them will reduce the costs related to station-keeping and then increasing the duration of the mission. In some previous studies, a search for frozen orbit around Europa was presented based in average techniques. The present research has the objective of using the new concept of stability of orbits with respect to station-keeping maneuvers that is available in the literature to study circular orbits around Europa. This concept is based in the integral of the perturbing forces over the time. This value can estimate the total variation of velocity required by the station-keeping propulsion system to compensate the perturbations suffered by the spacecraft. The value of this integral is a characteristic
of the perturbations considered and the orbit chosen for the spacecraft. Numerical simulations are made showing the costs of station-keeping for circular orbits around Europa are shown as a function of the eccentricity and semi-major axis of the orbits.
This study at aims performing the stability analysis of the rotational motion to artificial satel... more This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion.
In this paper, a search for low-altitude orbits around Europa is performed. An emphasis is given ... more In this paper, a search for low-altitude orbits around Europa is performed. An emphasis is given in frozen orbits. These orbits are used in the planning of aerospace activities to be conducted around this planetary satellite, with respect to the stability of orbits of artificial satellites. The study considers orbits of artificial satellites around Europa under the influence of the third-body perturbation (the gravitational attraction of Jupiter) and the polygenic perturbations. These last ones occur due to forces such as the non-uniform distribution of mass (J2 and J3) of the main (central) body. A simplified dynamic model for these perturbations is used. The
Lagrange planetary equations, which compose a system of nonlinear differential equations, are used to describe the orbital motion of the artificial satellite around Europa. The equations of motion are developed in closed form to avoid expansions in power series. Low-altitude polar orbits and frozen orbits with long lifetimes were found. This study can be used for planning of future space missions which seek to visit Europa and other planetary satellites.
Nowadays, there are several studies for missions that will place a satellite around Europa. There... more Nowadays, there are several studies for missions that will place a satellite around Europa. There are many important aspects that deserve to be studied in this natural satellite of Jupiter. It makes the study of orbits around Europa a particular important part of the mission, since a good choice for them will reduce the costs related to station-keeping and then increasing the duration of the mission. In some previous studies, a search for frozen orbit around Europa was presented based in average techniques. The present research has the objective of using the new concept of stability of orbits with respect to station-keeping maneuvers that is available in the literature to study circular orbits around Europa. This concept is based in the integral of the perturbing forces over the time. This value can estimate the total variation of velocity required by the station-keeping propulsion system to compensate the perturbations suffered by the spacecraft. The value of this integral is a characteristic
of the perturbations considered and the orbit chosen for the spacecraft. Numerical simulations are made showing the costs of station-keeping for circular orbits around Europa are shown as a function of the eccentricity and semi-major axis of the orbits.
This study at aims performing the stability analysis of the rotational motion to artificial satel... more This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion.