The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Alessandro Antonio Quarta - One of the best experts on this subject based on the ideXlab platform.

  • Electric sail phasing maneuvers with radial thrust
    Acta Astronautica, 2021
    Co-Authors: Marco Bassetto, Giovanni Mengali, Luisa Boni, Alessandro Antonio Quarta
    Abstract:

    Abstract We address the Heliocentric in-orbit repositioning problem of an E-sail-based spacecraft that covers a circular parking orbit of given radius, with the assumption that the propulsive acceleration is directed along the Sun-spacecraft line. According to the recent literature, the analysis exploits the possibility of reducing the mathematical problem to the dynamics of an equivalent nonlinear oscillator with a single degree of freedom. The analytical expression of the spacecraft Heliocentric Trajectory, which is available in polar form when its motion is periodic, is used to obtain approximate relationships among the E-sail performance, the flight time, and the desired phasing angle. The approximate analytical model is validated through numerical simulations, whereas the last part of the paper discusses a comparison with the optimal in-orbit repositioning transfers available in the literature.

  • Effects of optical parameter measurement uncertainties and solar irradiance fluctuations on solar sailing
    Advances in Space Research, 2019
    Co-Authors: Lorenzo Niccolai, Giovanni Mengali, Alessandro Anderlini, Alessandro Antonio Quarta
    Abstract:

    Abstract The Heliocentric orbital dynamics of a spacecraft propelled by a solar sail is affected by some uncertainty sources, including possible inaccuracies in the measurement of the sail film optical properties. Moreover, the solar radiation pressure, which is responsible for the solar sail propulsive acceleration generation, is not time-constant and is subject to fluctuations that are basically unpredictable and superimposed to the well-known 11-year solar activity cycle. In this context, this work aims at investigating the effects of such uncertainties on the actual Heliocentric Trajectory of a solar sail by means of stochastic simulations performed with a generalized polynomial chaos procedure. The numerical results give an estimation of their impact on the actual Heliocentric Trajectory and identify whether some of the uncertainty sources are more relevant than others. This is a fundamental information for directing more accurate theoretical and experimental efforts toward the most important parameters, in order to obtain an accurate knowledge of the solar sail thrust vector characteristics and, eventually, of the spacecraft Heliocentric position.

  • Electric sail displaced orbit control with solar wind uncertainties
    Acta Astronautica, 2019
    Co-Authors: Lorenzo Niccolai, Giovanni Mengali, Alessandro Anderlini, Alessandro Antonio Quarta
    Abstract:

    Abstract The working principle of the Electric Solar Wind Sail, an innovative propellantless propulsion system proposed in 2004, is based on the electrostatic interaction between a spinning grid of tethers, kept at a high positive potential, and the incoming ions from the solar wind. Similar to the well-known solar sail concept, the E-sail could simplify the feasibility of advanced (deep space) missions which would otherwise require a significative amount of propellant, if enabled by conventional thrusters. However, the intrinsic variability of the solar wind properties makes accurate Trajectory tracking a difficult task, since the perturbations of the solar wind dynamic pressure have the same order of magnitude as their mean value. To circumvent such a problem, in a recent study the plasma dynamic pressure was modelled as a random variable with a gamma probability density function and the sail grid voltage was suggested to be varied as a function of the instantaneous value of the solar wind properties. The aim of this paper is to improve those results, by discussing a more accurate statistical model of the solar wind dynamic pressure, which is used in the numerical simulations to estimate the actual impact of the solar wind uncertainties on the spacecraft Heliocentric Trajectory. In particular, the paper proposes a control law that is able to accurately track a nominal, non-Keplerian orbit.

  • Relative Motion of Sun-Pointing Smart Dust in Circular Heliocentric Orbits
    Journal of Guidance Control and Dynamics, 2018
    Co-Authors: Giovanni Mengali, Alessandro Antonio Quarta, Eugenio Denti
    Abstract:

    The aim of thisNote is to extend the results of [12] to the study of the linearized relative motion of a sun-pointing SD and an MS when the latter describes a circular Heliocentric orbit. More precisely, assuming the sun–SD distance to be close to the MS orbital radius, the linearized relative dynamics between SD and MS is described with an approach similar to that used by McInnes in the analysis of the azimuthal repositioning problem for a solar sail-based spacecraft.\ud The contribution in the study to follow is therefore different from that discussed in [12], whose aim, instead, is to find the SD Heliocentric Trajectory as a function of a given control law. The results about the SD–MS relative dynamics are obtained in an analytical form and are applied to a phasing mission case, a scenario in which the SD varies its angular position (along the circular reference orbit) with respect to that of the MS

  • Heliocentric Trajectory analysis of Sun-pointing smart dust with electrochromic control
    Advances in Space Research, 2016
    Co-Authors: Giovanni Mengali, Alessandro Antonio Quarta
    Abstract:

    A smart dust is a micro spacecraft, with a characteristic side length on the order of a few millimeters, whose surface is coated with electrochromic material. Its orbital dynamics is controlled by exploiting the differential force due to the solar radiation pressure, which is obtained by modulating the reflectivity coefficient of the electrochromic material within a range of admissible values. A significant thrust level can be reached due to the high values of area-to-mass ratio of such a spacecraft configuration. Assuming that the smart dust is designed to achieve a passive Sun-pointing attitude, the propulsive acceleration due to the solar radiation pressure lies along the Sun-spacecraft direction. The aim of this paper is to study the smart dust Heliocentric dynamics in order to find a closed form, analytical solution of its Trajectory when the reflectivity coefficient of the electrochromic material can assume two values only. The problem is addressed by introducing a suitable transformation that regularizes the spacecraft motion and translates the smart-dust dynamics into that of a linear harmonic oscillator with unitary frequency, whose forcing input is a boxcar function. The solution is found using the Laplace transform method, and afterwards the problem is generalized by accounting for the degradation of the electrochromic material due to its exposition to the solar radiation. Three spacecraft configurations, corresponding to low, medium and high performance smart dusts, are finally used to quantify the potentialities of these advanced devices in an interplanetary mission scenario.

Giovanni Mengali - One of the best experts on this subject based on the ideXlab platform.

  • Electric sail phasing maneuvers with radial thrust
    Acta Astronautica, 2021
    Co-Authors: Marco Bassetto, Giovanni Mengali, Luisa Boni, Alessandro Antonio Quarta
    Abstract:

    Abstract We address the Heliocentric in-orbit repositioning problem of an E-sail-based spacecraft that covers a circular parking orbit of given radius, with the assumption that the propulsive acceleration is directed along the Sun-spacecraft line. According to the recent literature, the analysis exploits the possibility of reducing the mathematical problem to the dynamics of an equivalent nonlinear oscillator with a single degree of freedom. The analytical expression of the spacecraft Heliocentric Trajectory, which is available in polar form when its motion is periodic, is used to obtain approximate relationships among the E-sail performance, the flight time, and the desired phasing angle. The approximate analytical model is validated through numerical simulations, whereas the last part of the paper discusses a comparison with the optimal in-orbit repositioning transfers available in the literature.

  • Effects of optical parameter measurement uncertainties and solar irradiance fluctuations on solar sailing
    Advances in Space Research, 2019
    Co-Authors: Lorenzo Niccolai, Giovanni Mengali, Alessandro Anderlini, Alessandro Antonio Quarta
    Abstract:

    Abstract The Heliocentric orbital dynamics of a spacecraft propelled by a solar sail is affected by some uncertainty sources, including possible inaccuracies in the measurement of the sail film optical properties. Moreover, the solar radiation pressure, which is responsible for the solar sail propulsive acceleration generation, is not time-constant and is subject to fluctuations that are basically unpredictable and superimposed to the well-known 11-year solar activity cycle. In this context, this work aims at investigating the effects of such uncertainties on the actual Heliocentric Trajectory of a solar sail by means of stochastic simulations performed with a generalized polynomial chaos procedure. The numerical results give an estimation of their impact on the actual Heliocentric Trajectory and identify whether some of the uncertainty sources are more relevant than others. This is a fundamental information for directing more accurate theoretical and experimental efforts toward the most important parameters, in order to obtain an accurate knowledge of the solar sail thrust vector characteristics and, eventually, of the spacecraft Heliocentric position.

  • Electric sail displaced orbit control with solar wind uncertainties
    Acta Astronautica, 2019
    Co-Authors: Lorenzo Niccolai, Giovanni Mengali, Alessandro Anderlini, Alessandro Antonio Quarta
    Abstract:

    Abstract The working principle of the Electric Solar Wind Sail, an innovative propellantless propulsion system proposed in 2004, is based on the electrostatic interaction between a spinning grid of tethers, kept at a high positive potential, and the incoming ions from the solar wind. Similar to the well-known solar sail concept, the E-sail could simplify the feasibility of advanced (deep space) missions which would otherwise require a significative amount of propellant, if enabled by conventional thrusters. However, the intrinsic variability of the solar wind properties makes accurate Trajectory tracking a difficult task, since the perturbations of the solar wind dynamic pressure have the same order of magnitude as their mean value. To circumvent such a problem, in a recent study the plasma dynamic pressure was modelled as a random variable with a gamma probability density function and the sail grid voltage was suggested to be varied as a function of the instantaneous value of the solar wind properties. The aim of this paper is to improve those results, by discussing a more accurate statistical model of the solar wind dynamic pressure, which is used in the numerical simulations to estimate the actual impact of the solar wind uncertainties on the spacecraft Heliocentric Trajectory. In particular, the paper proposes a control law that is able to accurately track a nominal, non-Keplerian orbit.

  • Relative Motion of Sun-Pointing Smart Dust in Circular Heliocentric Orbits
    Journal of Guidance Control and Dynamics, 2018
    Co-Authors: Giovanni Mengali, Alessandro Antonio Quarta, Eugenio Denti
    Abstract:

    The aim of thisNote is to extend the results of [12] to the study of the linearized relative motion of a sun-pointing SD and an MS when the latter describes a circular Heliocentric orbit. More precisely, assuming the sun–SD distance to be close to the MS orbital radius, the linearized relative dynamics between SD and MS is described with an approach similar to that used by McInnes in the analysis of the azimuthal repositioning problem for a solar sail-based spacecraft.\ud The contribution in the study to follow is therefore different from that discussed in [12], whose aim, instead, is to find the SD Heliocentric Trajectory as a function of a given control law. The results about the SD–MS relative dynamics are obtained in an analytical form and are applied to a phasing mission case, a scenario in which the SD varies its angular position (along the circular reference orbit) with respect to that of the MS

  • Heliocentric Trajectory analysis of Sun-pointing smart dust with electrochromic control
    Advances in Space Research, 2016
    Co-Authors: Giovanni Mengali, Alessandro Antonio Quarta
    Abstract:

    A smart dust is a micro spacecraft, with a characteristic side length on the order of a few millimeters, whose surface is coated with electrochromic material. Its orbital dynamics is controlled by exploiting the differential force due to the solar radiation pressure, which is obtained by modulating the reflectivity coefficient of the electrochromic material within a range of admissible values. A significant thrust level can be reached due to the high values of area-to-mass ratio of such a spacecraft configuration. Assuming that the smart dust is designed to achieve a passive Sun-pointing attitude, the propulsive acceleration due to the solar radiation pressure lies along the Sun-spacecraft direction. The aim of this paper is to study the smart dust Heliocentric dynamics in order to find a closed form, analytical solution of its Trajectory when the reflectivity coefficient of the electrochromic material can assume two values only. The problem is addressed by introducing a suitable transformation that regularizes the spacecraft motion and translates the smart-dust dynamics into that of a linear harmonic oscillator with unitary frequency, whose forcing input is a boxcar function. The solution is found using the Laplace transform method, and afterwards the problem is generalized by accounting for the degradation of the electrochromic material due to its exposition to the solar radiation. Three spacecraft configurations, corresponding to low, medium and high performance smart dusts, are finally used to quantify the potentialities of these advanced devices in an interplanetary mission scenario.

Dong Qiao - One of the best experts on this subject based on the ideXlab platform.

  • Design of low-energy transfer from lunar orbit to asteroid in the Sun-Earth-Moon system
    Acta Mechanica Sinica, 2014
    Co-Authors: Yamin Wang, Dong Qiao
    Abstract:

    Asteroid exploration trajectories which start from a lunar orbit are investigated in this work. It is assumed that the probe departs from lunar orbit and returns to the vicinity of Earth, then escapes from the Earth by performing a perigee maneuver. A low-energy transfer in Sun-Earth-Moon system is adopted. First, the feasible region of low-energy transfer from lunar orbit to perigee within 5 000km height above the Earth surface in Sun-Earth-Moon system is calculated and analyzed. Three transfer types are found, i.e., large maneuver and fast transfers, small maneuver and fast transfers, and disordered and slow transfers. Most of feasibility trajectories belong to the first two types. Then, the low-energy Trajectory leg from lunar orbit to perigee and a Heliocentric Trajectory leg from perigee to asteroid are patched by a perigee maneuver. The optimal full-transfer Trajectory is obtained by exploiting the differential evolution algorithm. Finally, taking 4179 Toutatis asteroid as the target, some low-energy transfer trajectories are obtained and analyzed.

  • Opportunities search of transfer between interplanetary halo orbits in ephemeris model
    Science China Technological Sciences, 2012
    Co-Authors: Wang Yamin, Pingyuan Cui, Dong Qiao
    Abstract:

    In this paper, a two-level search method for searching transfer opportunities between interplanetary halo orbits, exploiting the invariant manifolds of the restricted three-body problem, is proposed. In the method, the first-level search procedure is performed under the conditions of the initial time of escape manifold Trajectory of the Sun-Earth halo orbit and the terminal time of capture manifold of the target planet fixed, by solving the optimal two-impulsive Heliocentric Trajectory to connect the two manifold trajectories. The contour map, helpful to the understanding of the global characteristics of the transfer opportunities, taking the initial time of escape manifold and the terminal time of capture manifold as variables, the optimal velocity increment of the first-level search as objective function, is used for the second-level search. Finally, taking the Earth-Mars and Earth-Venus halo to halo transfers for example, the transfer opportunities in 2015–2017 are searched. The results show the effectiveness of the proposed method and reveal the property of quasi-period of transfer opportunities between interplanetary halo orbits.

Quarta A - One of the best experts on this subject based on the ideXlab platform.

  • Solar sailing with force model uncertainties and solar irradiance fluctuations
    2019
    Co-Authors: Niccolai L, Anderlini A, Mengali G, Quarta A
    Abstract:

    The Heliocentric orbital dynamics of a spacecraft propelled by a solar sail is affected by some uncertainty sources, mostly due to the possible measurement inaccuracies of the sail film optical properties. Moreover, the solar radiation pressure, which induces the propulsive acceleration generation on the solar sail, is not constant with time, rather it is subjected to fluctuations that are hardly predictable and superimposed to the 11-year-long solar activity cycle. The aim of this work is to investigate the effects of such uncertainties on the actual Heliocentric Trajectory of a solar sail-based spacecraft by means of stochastic simulations, which are performed with a generalized polynomial chaos procedure. The obtained results are able to give an estimate of the uncertainty impact on the actual Heliocentric Trajectory and to identify the more important uncertainty sources. This is a fundamental step for obtaining more accurate theoretical and experimental information on the parameters that chiefly affect the thrust vector characteristics and ultimately the solar sail Trajectory

  • Electric sail phasing maneuvers with radial thrust
    2019
    Co-Authors: Bassetto M, Mengali G, Boni L, Quarta A
    Abstract:

    This paper addresses the Heliocentric in-orbit repositioning problem of an E-sail-based spacecraft that covers a circular parking orbit, with the assumption that the propulsive acceleration is directed along the Sun-spacecraft line. The analysis exploits the possibility of reducing the problem to the dynamics of an equivalent nonlinear oscillator with a single degree of freedom. The analytical expression of the spacecraft Heliocentric Trajectory, which is available in polar form when the motion is periodic, is used to obtain approximate relationships between the E-sail performance, the flight time and the phasing angle. The approximate analytical model is validated through numerical simulations, and the last part of the paper discusses a comparison with the optimal in-orbit repositioning transfers available in the recent literature

Cyrus Foster - One of the best experts on this subject based on the ideXlab platform.

  • Trajectory Browser: An online tool for interplanetary Trajectory analysis and visualization
    2013 IEEE Aerospace Conference, 2013
    Co-Authors: Cyrus Foster
    Abstract:

    The Trajectory Browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and ΔV requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and ΔV capability, while a Trajectory viewer tool allows the visualization of the Heliocentric Trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies. The educational potential of the website is also recognized for academia and the public with regards to Trajectory design, a field that has generally been poorly understood by the public. The website is currently hosted on NASA-internal URL http://trajbrowser.arc.nasa.gov/ with plans for a public release in early 2013.

  • Trajectory Browser Website
    2012
    Co-Authors: Cyrus Foster, Belgacem Jaroux
    Abstract:

    The Trajectory Browser is a web-based tool developed at the NASA Ames Research Center to be used for the preliminary assessment of trajectories to small-bodies and planets and for providing relevant launch date, time-of-flight and V requirements. The site hosts a database of transfer trajectories from Earth to asteroids and planets for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and delta V capability, while a Trajectory viewer tool allows the visualization of the Heliocentric Trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies. The educational potential of the website is also recognized for academia and the public with regards to Trajectory design, a field that has generally been poorly understood by the public. The website is currently hosted on NASA-internal URL http://trajbrowser.arc.nasa.gov/ with plans for a public release as soon as development is complete.