A. F. B. A. Prado
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View article: Satellite constellation design for Titan exploration: orbit design and performance assessment
Satellite constellation design for Titan exploration: orbit design and performance assessment Open
Satellite constellations allow distributed tasks among multiple spacecraft, reducing mission time and enhancing objectives. Interest in constellations has increased due to reduced costs in satellite production and launch. A key step in con…
View article: Model Predictive Control for Gliding Descent on Mars
Model Predictive Control for Gliding Descent on Mars Open
This paper proposes a closed-loop nonlinear model predictive control for the first time for the trajectory tracking of a spaceplane descending and gliding on Mars. Previous studies presented the optimization of descending trajectory solvin…
View article: On the Dynamics of a Synchronous Binary Asteroid System with Non-Uniform Mass Distribution
On the Dynamics of a Synchronous Binary Asteroid System with Non-Uniform Mass Distribution Open
In this work, particle dynamics in a binary asteroid system is analyzed within the Circular Restricted Three-Body Problem (CRTBP) framework, assuming the largest body is treated as a mass point. The secondary body is modeled as a mass dipo…
View article: Analytical modeling of the gravitational potential of irregularly shaped celestial bodies considering three distinct internal structures: application to (21) Lutetia
Analytical modeling of the gravitational potential of irregularly shaped celestial bodies considering three distinct internal structures: application to (21) Lutetia Open
The classical polyhedral model is one of the most accurate methods currently used to represent the gravitational field of irregularly shaped bodies. However, it assumes a homogeneous density distribution, which may not accurately reflect t…
View article: Potential series expansion method applied in Analytical Modeling of Gravitational field of Irregularly Shaped Celestial Bodies
Potential series expansion method applied in Analytical Modeling of Gravitational field of Irregularly Shaped Celestial Bodies Open
This study aims to establish an analytical model that reproduces the gravitational field around non-spherical bodies with constant density. Due to the non-spherical geometry of such bodies, their gravitational potential is disturbed relati…
View article: Investigation of optimal transfers to retrograde co-orbital orbits in the Earth-Moon system
Investigation of optimal transfers to retrograde co-orbital orbits in the Earth-Moon system Open
Recent findings on retrograde co-orbital mean-motion resonances in the Earth-Moon system, highlight the potential use of spacecraft in retrograde resonances. Based on these discoveries, this study investigates retrograde co-orbital resonan…
View article: Rendezvous Missions to Systems of Small Solar System Bodies Using the Suboptimal SDRE Control Approach
Rendezvous Missions to Systems of Small Solar System Bodies Using the Suboptimal SDRE Control Approach Open
In this work, we analyze the suitability of the State-Dependent Riccati Equation (SDRE) suboptimal nonlinear control formulation for the implementation of body-fixed hovering of a spacecraft in the highly nonlinear environment engendered b…
View article: Orbital Transfers in a Binary Asteroid System Considering Flattening of the Bodies and Solar Radiation Pressure
Orbital Transfers in a Binary Asteroid System Considering Flattening of the Bodies and Solar Radiation Pressure Open
This paper aims to investigate the effects of asteroid size and shape and solar radiation pressure in the trajectories of a spacecraft in transfers between the collinear equilibrium points of a binary non-spherical asteroid system. As an e…
View article: Swing-By in Three Dimensions: Closed Form Solutions
Swing-By in Three Dimensions: Closed Form Solutions Open
The main goal of the present research is to make a summary of analytical equations that can be found to calculate a swing-by maneuver in the three-dimensional space. Analytical equations based in the patched conics approximation are showed…
View article: Optimal Gliding Trajectories for Descent on Mars
Optimal Gliding Trajectories for Descent on Mars Open
In this paper, optimal gliding trajectories are analyzed, formulating an optimal control problem to be solved computationally via nonlinear programming. A multi-objective terminal cost function that minimizes the velocity, altitude, horizo…
View article: Image Classification of Retrograde Resonance in the Planar Circular Restricted Three-Body Problem
Image Classification of Retrograde Resonance in the Planar Circular Restricted Three-Body Problem Open
. IntroductionThe advancement of computational techniques and methods such as artificial intelligence applied to celestial mechanics, including image classification. These techniques have been applied in the identification of mean motion r…
View article: Tangential velocity constraint for orbital maneuvers with Theory of Functional Connections
Tangential velocity constraint for orbital maneuvers with Theory of Functional Connections Open
Maneuvering a spacecraft in the cislunar space is a complex problem, since it is highly perturbed by the gravitational influence of both the Earth and the Moon, and possibly also the Sun. Trajectories minimizing the needed fuel are general…
View article: Planar dynamics of non-spherical close tidally locked binaries asteroids 
Planar dynamics of non-spherical close tidally locked binaries asteroids  Open
Asteroids are originated by the evolution of the disk in the Solar System and, in general, do not have spherical and symmetrical shapes. The reason for those irregular shapes is the small mass of the bodies, such that gravity is not suffic…
View article: Tangent Velocity constraint for orbital maneuvers with Theory of Functional Connections
Tangent Velocity constraint for orbital maneuvers with Theory of Functional Connections Open
Maneuvering a spacecraft in the cislunar space is a complex problem, since it is highly perturbed by the gravitational influence of both the Earth and the Moon, and possibly also the Sun. Trajectories minimizing the needed fuel are general…
View article: A comparison of performances of Brazilian and Chinese Universities in academic and industrial products using the “U-Multirank”
A comparison of performances of Brazilian and Chinese Universities in academic and industrial products using the “U-Multirank” Open
Background and aims The present work studies the performances of Brazilian and Chinese Universities considering academic and industrial related products. A comparison of the behavior of Universities that belong to these two countries are i…
View article: Study of the multidimensional academic ranking U-Multirank
Study of the multidimensional academic ranking U-Multirank Open
The present paper explores the dimensions and indicators of the international multidimensional academic ranking U-Multirank. Studying this ranking is important in Brazil today, as the new evaluation of graduate programs in the country is i…
View article: Orbit transfer using Theory of Functional Connections via change of variables
Orbit transfer using Theory of Functional Connections via change of variables Open
This work shows that a class of astrodynamics problems subject to mission constraints can be efficiently solved using the Theory of Functional Connections (TFC) mathematical framework by a specific change of coordinates. In these problems,…
View article: Shallow Encounters' Impact on Asteroid Deflection Prediction and Implications on Trajectory Design
Shallow Encounters' Impact on Asteroid Deflection Prediction and Implications on Trajectory Design Open
Analytical approximations are commonly employed in the initial trajectory design phase of a mission to rapidly explore a broad design space. In the context of an asteroid deflection mission, accurately predicting deflection is crucial to d…
View article: Suppression of Chaotic Motion of Tethered Satellite Systems Using Tether Length Control
Suppression of Chaotic Motion of Tethered Satellite Systems Using Tether Length Control Open
This study focuses on attitude and control motion of two bodies (a base-satellite and a sub-satellite) connected by an inextensible and massless tether in a circular orbit under the influence of the Earths gravitational force. The base-sat…
View article: Theory of Functional Connections and Nelder-Mead optimization methods applied in satellite characterization
Theory of Functional Connections and Nelder-Mead optimization methods applied in satellite characterization Open
The growing population of man-made objects with the build up of mega-constellations not only increases the potential danger to all space vehicles and in-space infrastructures (including space observatories), but above all poses a serious t…
View article: Numerical investigations of the orbital dynamics around a synchronous binary system of asteroids
Numerical investigations of the orbital dynamics around a synchronous binary system of asteroids Open
In this article, equilibrium points and families of periodic orbits in the vicinity of the collinear equilibrium points of a binary asteroid system are investigated with respect to the angular velocity of the secondary body, the mass ratio…
View article: Dynamics Around an Asteroid Modeled as a Mass Tripole
Dynamics Around an Asteroid Modeled as a Mass Tripole Open
The orbital dynamics of a spacecraft orbiting around irregular small celestial bodies is a challenging problem. Difficulties to model the gravity field of these bodies arise from the poor knowledge of the exact shape as observed from the E…
View article: Analysis of the dynamics of a spacecraft in the vicinity of an asteroid binary system with equal masses
Analysis of the dynamics of a spacecraft in the vicinity of an asteroid binary system with equal masses Open
In this work, we performed a dynamical analysis of a spacecraft around a nearly equal-mass binary near-Earth asteroid with application to the asteroid 2017 YE5, which is also a possible dormant Jupiter-family comet. Thus, we investigated t…
View article: Using Upgraded Versions Of Close Approach Maneuvers As Transportation Solutions For Deep Space Missions
Using Upgraded Versions Of Close Approach Maneuvers As Transportation Solutions For Deep Space Missions Open
Gravity-Assisted maneuvers have been used as a technique to reduce fuel consumption in deep space missions for several decades now. It opened the doors of the exterior solar system. The literature shows those results, as well as new versio…
View article: Strategies For Non-Planar Configurations Of Geostationary Tethered Collecting Solar Power Satellite Systems
Strategies For Non-Planar Configurations Of Geostationary Tethered Collecting Solar Power Satellite Systems Open
To collect additional solar energy during the hours of darkness and to overcome the limited Terrestrial solar power due to the diurnal day night cycle, the concept of a Geostationary Tethered Collecting Solar Power Satellite System has bee…
View article: Mapping and maneuvering long-term natural orbits around Titania, a satellite of Uranus
Mapping and maneuvering long-term natural orbits around Titania, a satellite of Uranus Open
In this work, we present the results of a set of numerical simulations carried out to obtain long-duration orbits for a probe around Titania, Uranus' largest satellite. We also propose orbital maneuvers to extend the lifetime of some orbit…
View article: Parametric Optimization of Low Thrust Orbital Maneuvers
Parametric Optimization of Low Thrust Orbital Maneuvers Open
The goal of the present paper is to make a numerical analysis of parametric optimization of low thrust orbital maneuver. An orbital maneuver occurs when it is necessary to modify the orbit a space vehicle to change its function or to corre…