The Experts below are selected from a list of 2493 Experts worldwide ranked by ideXlab platform

Shengping Gong - One of the best experts on this subject based on the ideXlab platform.

  • refractive sail and its applications in Solar sailing
    Aerospace Science and Technology, 2018
    Co-Authors: Shahin Firuzi, Shengping Gong
    Abstract:

    Abstract Radiation pressure can be generated by interactions of electromagnetic (EM) waves with matter. Conventional in-space photonic propulsion systems like Solar Sails or Solar photon thrusters operate by reflection of EM waves. This paper introduces a new type of Solar sail which generates thrust by means of refraction of light through a thin film composed of micro-prisms. The main feature of the proposed refractive sail is its relatively large tangential radiation pressure, generated at near-normal radiation incidence. A method for computation of radiation pressure, by having the direction and power of input and output light beams, was introduced. Then a simple analytical approach for optimal design of the refractive film was presented, and ray tracing was utilized for computation of the radiation pressure to a good approximation. A refractive sail can be utilized in applications which a tangential force, especially at near-normal radiation incidence, is required. By utilizing this sail for orbit raising from low-Earth orbit (LEO), the minimum possible altitude for Solar sailing can be reduced to about 500 km under the mean Solar activity. Attitude control of Solar Sails along the sail's normal axis is another possible application of refractive films. Refractive films can also be utilized as Solar collector (Fresnel lens) in space, which besides the convenience of their shape keeping, can be designed to be passively stable at the Sun-pointing attitude.

  • dynamics and control of flexible spinning Solar Sails under reflectivity modulation
    Advances in Space Research, 2015
    Co-Authors: Shengping Gong
    Abstract:

    Abstract Electrochromic devices have been used for the attitude control of a spinning Solar sail in a deep space mission by modulating the reflectivity of the sail membrane. As a flexible spinning Solar sail has no rigid structure to support its membrane, the distributed load due to Solar radiation will lead to the deformation of the sail membrane, and the control torque generated by reflectivity modulation can introduce oscillatory motion to the membrane. By contrast, the deformation and oscillatory motion of the sail membrane have an impact on the performance of the reflectivity control. This paper investigates the dynamics and control of flexible spinning Solar Sails under reflectivity modulation. The static deformation of a spinning sail membrane subjected to Solar radiation pressure in an equilibrium state is analyzed. The von Karman theory is used to obtain the displacements and the stress distribution in the equilibrium states. A simplified analytical first-order mode is chosen to model the membrane oscillation. The coupled membrane oscillation-attitude-orbit dynamics are considered for a GeoSail formation flying mission. The relative attitude and orbit control of flexible spinning Solar Sails under reflectivity modulation are numerically tested. The simulations indicate that the membrane deformation and oscillation have a lower impact on the control of the reflectivity modulated Sails than the increase of the spinning rate.

  • equilibria near asteroids for Solar Sails with reflection control devices
    Astrophysics and Space Science, 2015
    Co-Authors: Shengping Gong
    Abstract:

    Solar Sails are well-suited for long-term, multiple-asteroid missions. The dynamics of Solar Sails near an asteroid have not yet been studied in detail. In this paper, out-of-plane artificial equilibria in a Sun-asteroid rotating frame and hovering points in a body-fixed rotating frame are studied (using a Solar sail equipped with reflection control devices). First, the dynamics and the stability of out-of-plane artificial equilibria are studied as an elliptical restricted three body problem. Next, the body-fixed hovering problem is discussed as a two-body problem. Hovering flight is only possible for certain values of the latitude of the asteroid’s orbit. In addition, the feasible range of latitudes is determined for each landmark on the asteroid’s surface. The influence of the sail lightness number on the feasible range is also illustrated. Several special families of hovering points are discussed. These points include points above the equator and poles and points with an altitude equal to the radius of the synchronous orbit. In both of these types of problems, the Solar sail (equipped with reflection control devices) can equilibrate over a large range of locations.

  • reflectivity controlled Solar sail formation flying for magnetosphere mission
    Aerospace Science and Technology, 2013
    Co-Authors: Shengping Gong
    Abstract:

    Abstract Recently, a reflectivity modulation technology was successfully tested in the worldʼs first Solar sail demonstration mission. In the mission, a reflectivity control device was employed to generate a torque to control the attitude of the sail effectively. In this study, a novel approach that uses the same reflectivity modulation technology is proposed for the active control of Solar Sails. In addition to its original goal of attitude control, the reflectivity modulation ratio can be used directly together with the attitude angles as control variables for trajectory-tracking problems. The application of the technology in formation flying for magnetosphere mission is investigated. The steering law and the reflectivity modulation ratio budget for the reflectivity-controlled Solar sail are analyzed for the mission. Two controllers are applied to study the control of Solar Sails for reference trajectory tracking. Solar sail formation flying in the reference orbit is shown to be controllable by making small variations in the reflectivity modulation ratio and two attitude angles. The proposed method further enhances the control of Solar Sails without creating any additional complications in the Solar sail design. The method can be used in other Solar sail applications in which active control is necessary.

  • a curved surface Solar radiation pressure force model for Solar sail deformation
    Science China-physics Mechanics & Astronomy, 2012
    Co-Authors: Shengping Gong
    Abstract:

    A precise force model is of vital importance for dynamics and control of Solar Sails. Among various factors, deviations from the ideal flat Sails, elastic deformations of the Sails, are really important as most Solar Sails are large flexible membranes. In this study, the deformed Sails are modeled as smooth curved surfaces and a general total force model (GTFM) for the deformed Sails is proposed. Various simplified versions of this GTFM are also derived for the symmetric deformation cases. Furthermore, differences between the ideal force models and our precise GTFM are investigated. The numerical results demonstrate that both the previous ideal reflected model and flat optical model are not as satisfactory as claimed before, by contrast with the actual dynamics from the GTFM. Thus this work paves the way for sail craft’s precise navigation where exact forces are needed.

Grundmann, Jan Thimo - One of the best experts on this subject based on the ideXlab platform.

  • Flights Are Ten a Sail – Re-use and Commonality in the Design and System Engineering of Small Spacecraft Solar Sail Missions with Modular Hardware for Responsive and Adaptive Exploration
    2019
    Co-Authors: Grundmann, Jan Thimo, Bauer Waldemar, Boden Ralf, Ceriotti Matteo, Cordero Federico, Dachwald Bernd, Dumont Etienne, Grimm, Christian D., Chand Suditi, Heiligers Jeannette
    Abstract:

    The exploration of small Solar system bodies started with fast fly-bys of opportunity on the sidelines of missions to the planets. The tiny new worlds seen turned out to be so intriguing and different from all else(and each other) that dedicated sample-return and in-situ analysis missions were developed and launched. Through these, highly efficient low-thrust propulsion expanded from commercial use into mainstream and flagship science missions, there in combination with gravity assists. In parallel, the growth of small spacecraft solutions accelerated in numbers as well as individual spacecraft capabilities. The on-going missions OSIRIS-REx (NASA) or Hayabusa2 (JAXA) with its landers MINERVA-II and MASCOT, and the upcoming NEA scout mission are examples of this synergy of trends. The continuation of these and other related developments towards a propellant-less and highly efficient class of spacecraft for Solar system exploration emerges in the form of small spacecraft Solar Sails designed for carefree handling and equipped with carried landers and application modules. These address the needs of all asteroid user communities– planetary science, planetary defence, and in-situ resource utilization – as well as other fields of Solar system science and applications such as space weather warning and Solar observations. Already the DLR-ESTEC GOSSAMER Roadmap for Solar Sailing initiated studies of missions uniquely feasible with Solar Sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter(SPO) delivery, which demonstrate the capabilities of near-term Solar Sails to reach any kind of orbit in the inner Solar system. This enables Multiple Near-Earth Asteroid (NEA) rendezvous missions (MNR),from Earth-coorbital to extremely inclined and even retrograde target orbits. For these mission types using separable payloads, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER Solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the targets visited and enable multiple NEA sample-return missions. These nanospacecraft scale components are an ideal match creating Solar Sails in micro-spacecraft format whose launch configurations are compatible with secondary payload platforms such as ESPA and ASAP. The DLR GOSSAMER Solar sail technology builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m) Solar sail at DLR Cologne in 1999 and in the 20 years since

  • Solar Sails for Planetary Defense & High-Energy Missions
    'Institute of Electrical and Electronics Engineers (IEEE)', 2019
    Co-Authors: Grundmann, Jan Thimo, Bauer Waldemar, Biele Jens, Boden Ralf, Borchers Kai, Ceriotti Matteo, Cordero Federico, Dachwald Bernd, Dumont Etienne, Grimm Christian
    Abstract:

    20 years after the successful ground deployment test of a (20 m)² Solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and hardware design studies as well as the hardware built in the course of our Solar sail technology development. We outline the most likely and most efficient routes to develop Solar Sails for useful missions in science and applications, based on our developed `now-term' and near-term hardware as well as the many practical and managerial lessons learned from the DLR-ESTEC Gossamer Roadmap. Mission types directly applicable to planetary defense include single and Multiple NEA Rendezvous ((M)NR) for precursor, monitoring and follow-up scenarios as well as sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation. Other mission types such as the Displaced L1 (DL1) space weather advance warning and monitoring or Solar Polar Orbiter (SPO) types demonstrate the capability of near-term Solar Sails to achieve asteroid rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. Some of these mission types such as SPO, (M)NR and RKI include separable payloads. For one-way access to the asteroid surface, nanolanders like MASCOT are an ideal match for Solar Sails in micro-spacecraft format, i.e. in launch configurations compatible with ESPA and ASAP secondary payload platforms. Larger landers similar to the JAXA-DLR study of a Jupiter Trojan asteroid lander for the OKEANOS mission can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. The high impact velocities and re-try capability achieved by the RKI mission type on a final orbit identical to the target asteroid's but retrograde to its motion enables small spacecraft size impactors to carry sufficient kinetic energy for deflection

  • Solar Sails for Planetary Defense and High-Energy Missions
    'Institute of Electrical and Electronics Engineers (IEEE)', 2019
    Co-Authors: Grundmann, Jan Thimo, Bauer Waldemar, Borchers Kai, Dumont Etienne, Grimm, Christian D., Ho Tra-mi, Jahnke Rico, Koch, Aaron D., Lange Caroline, Maiwald Volker
    Abstract:

    20 years after the successful ground deployment test of a (20 m)² Solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and hardware design studies as well as the hardware built in the course of our Solar sail technology development. We outline the most likely and most efficient routes to develop Solar Sails for useful missions in science and applications, based on our developed ‘now-term’ and near-term hardware as well as the many practical and managerial lessons learned from the DLR-ESTEC GOSSAMER Roadmap. Mission types directly applicable to planetary defense include single and Multiple NEA Rendezvous ((M)NR) for precursor, monitoring and follow-up scenarios as well as sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation. Other mission types such as the Displaced L1 (DL1) space weather advance warning and monitoring or Solar Polar Orbiter (SPO) types demonstrate the capability of near-term Solar Sails to achieve asteroid rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. Some of these mission types such as SPO, (M)NR and RKI include separable payloads. For one-way access to the asteroid surface, nanolanders like MASCOT are an ideal match for Solar Sails in micro-spacecraft format, i.e. in launch configurations compatible with ESPA and ASAP secondary payload platforms. Larger landers similar to the JAXA-DLR study of a Jupiter Trojan asteroid lander for the OKEANOS mission can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. The high impact velocities and re-try capability achieved by the RKI mission type on a final orbit identical to the target asteroid‘s but retrograde to its motion enables small spacecraft size impactors to carry sufficient kinetic energy for deflection

  • Flights are ten a sail - Re-use and commonality in the design and system engineering of small spacecraft Solar sail missions with modular hardware for responsive and adaptive exploration
    2019
    Co-Authors: Grundmann, Jan Thimo, Bauer Waldemar, Boden Ralf, Ceriotti Matteo, Chand Suditi, Heiligers M.j., Vergaaij Merel, Viavattene Giulia, Wolff Friederike
    Abstract:

    The exploration of small Solar system bodies started with fast fly-bys of opportunity on the sidelines of missions to the planets. The tiny new worlds seen turned out to be so intriguing and different from all else (and each other) that dedicated sample-return and in-situ analysis missions were developed and launched. Through these, highly efficient low-thrust propulsion expanded from commercial use into mainstream and flagship science missions, there in combination with gravity assists propulsion. In parallel, the growth of small spacecraft solutions accelerated in numbers as well as individual spacecraft capabilities. The on-going missions OSIRIS-REX (NASA) or HAYABUSA2 (JAXA) with its landers MINERVA-II and MASCOT, and the upcoming NEASCOUT mission are examples of this synergy of trends. The continuation of these and other related devlopments towards a propellant-less and highly efficient class of spacecraft for Solar system exploration emerges in the form of small spacecraft Solar Sails designed for carefree handling and equipped with carried landers and application modules. These address the needs of all asteroid user communities - planetary science, planetary defence, and in-situ resource utilization - as well as other fields of Solar system science and applications such as space weather warning and Solar observations. Already the DLR-ESTEC GOSSAMER Roadmap for Solar Sailing initiated studies of missions uniquely feasible with Solar Sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter (SPO) delivery, which demonstrate the capabilities of near-term Solar Sails to reach any kind of orbit in the inner Solar system. This enables Multiple Near-Earth Asteroid (NEA) rendezvous missions (MNR), from Earth-coorbital to extremely inclined and even retrograde target orbits. For these mission types using separable payloads, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER Solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the targets visited and enable multiple NEA sample-return missions. These nanospacecraft scale components are an ideal match creating Solar Sails in micro-spacecraft format whose launch configurations are compatible with secondary payload platforms such as ESPA and ASAP. The DLR GOSSAMER Solar sail technology builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m)2 Solar sail at DLR Cologne in 1999 and in the 20 years since.

  • Flights are ten a sail - Re-use and commonality in the design and system engineering of small spacecraft Solar sail missions with modular hardware for responsive and adaptive exploration
    2019
    Co-Authors: Grundmann, Jan Thimo, Bauer Waldemar, Boden Ralf, Ceriotti Matteo, Chand Suditi, Heiligers M.j., Vergaaij Merel, Viavattene Giulia, Wolff Friederike
    Abstract:

    The exploration of small Solar system bodies started with fast fly-bys of opportunity on the sidelines of missions to the planets. The tiny new worlds seen turned out to be so intriguing and different from all else (and each other) that dedicated sample-return and in-situ analysis missions were developed and launched. Through these, highly efficient low-thrust propulsion expanded from commercial use into mainstream and flagship science missions, there in combination with gravity assists propulsion. In parallel, the growth of small spacecraft solutions accelerated in numbers as well as individual spacecraft capabilities. The on-going missions OSIRIS-REX (NASA) or HAYABUSA2 (JAXA) with its landers MINERVA-II and MASCOT, and the upcoming NEASCOUT mission are examples of this synergy of trends. The continuation of these and other related devlopments towards a propellant-less and highly efficient class of spacecraft for Solar system exploration emerges in the form of small spacecraft Solar Sails designed for carefree handling and equipped with carried landers and application modules. These address the needs of all asteroid user communities - planetary science, planetary defence, and in-situ resource utilization - as well as other fields of Solar system science and applications such as space weather warning and Solar observations. Already the DLR-ESTEC GOSSAMER Roadmap for Solar Sailing initiated studies of missions uniquely feasible with Solar Sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter (SPO) delivery, which demonstrate the capabilities of near-term Solar Sails to reach any kind of orbit in the inner Solar system. This enables Multiple Near-Earth Asteroid (NEA) rendezvous missions (MNR), from Earth-coorbital to extremely inclined and even retrograde target orbits. For these mission types using separable payloads, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER Solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the targets visited and enable multiple NEA sample-return missions. These nanospacecraft scale components are an ideal match creating Solar Sails in micro-spacecraft format whose launch configurations are compatible with secondary payload platforms such as ESPA and ASAP. The DLR GOSSAMER Solar sail technology builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m)2 Solar sail at DLR Cologne in 1999 and in the 20 years since.Astrodynamics & Space Mission

Xiangyuan Zeng - One of the best experts on this subject based on the ideXlab platform.

  • Asteroid body-fixed hovering using nonideal Solar Sails
    Research in Astronomy and Astrophysics, 2015
    Co-Authors: Xiangyuan Zeng, Fanghua Jiang
    Abstract:

    The problem of body-fixed hovering over an asteroid using a compact form of nonideal Solar Sails with a controllable area is investigated. Nonlinear dynamic equations describing the hovering problem are constructed for a spherically symmetric asteroid. Numerical solutions of the feasible region for body-fixed hovering are obtained. Different sail models, including the cases of ideal, optical, parametric and Solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed. The required orientations for the sail and their corresponding variable lightness numbers are given for different hovering radii to identify the feasible region of the body-fixed hovering. An attractive scenario for a mission is introduced to take advantage of Solar sail hovering.

  • asteroid body fixed hovering using nonideal Solar Sails
    arXiv: Solar and Stellar Astrophysics, 2014
    Co-Authors: Xiangyuan Zeng, Fanghua Jiang
    Abstract:

    Asteroid body-fixed hovering problem using nonideal Solar sail models in a compact form with controllable sail area is investigated in this paper. The nonlinear dynamic equations for the hovering problem are constructed for a spherically symmetric asteroid. The feasible region for the body-fixed hovering is solved from the above equations by using a shooting method. The effect of the sail models, including the ideal, optical, parametric and Solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed in a parametric way. The required sail orientations and their corresponding variable lightness numbers are given for different hovering radii to identify the feasibility of the body-fixed hovering. An attractive mission scenario is introduced to enhance the advantage of the Solar sail hovering mission.

  • feasibility analysis of the angular momentum reversal trajectory via hodograph method for high performance Solar Sails
    Science China-technological Sciences, 2011
    Co-Authors: Xiangyuan Zeng, Hexi Baoyin, Shengping Gong
    Abstract:

    In this paper a new phase space of hodograph method is adopted to investigate and better understand the two-dimensional angular momentum reversal (H-reversal) trajectories for high performance Solar Sails within a fixed cone angle. As the hodograph method and the H-reversal trajectory are not very common, both of them are briefly introduced. The relationship between them are constructed and addressed with a sample trajectory. How the phase space varies according to the sail quality and the fixed sail cone angle is also studied. Through variation of the phase space, the minimum sail lightness number can be obtained by solving a set of algebraic equations instead of a parameter optimization problem. For a given sail lightness number, there are three types of the two-dimensional possible heliocentric motion, including the spiral inward trajectories towards the Sun, the H-reversal trajectories and the directly outward escape trajectories. The boundaries that separate these different groups are easily determined by using the phase space. Finally, the method and procedures to achieve the feasible region of the H-reversal trajectory with required perihelion distance are presented in detail.

  • three dimensional time optimal double angular momentum reversal trajectory using Solar Sails
    Celestial Mechanics and Dynamical Astronomy, 2011
    Co-Authors: Xiangyuan Zeng, Hexi Baoyin, Shengping Gong
    Abstract:

    A new concept of three dimensional non-Keplerian trajectories with double angular momentum reversal is investigated with high performance Solar Sails. The main discussion of this paper is about such 3D Solar inverse orbits with inner constraints. The problem is addressed in a time optimal control framework solved by an indirect method. Two typical Solar inverse orbits have been achieved and presented in a 3D non-dimensional dynamic model in the Heliocentric Inertial Frame. Starting from the Earth orbit ecliptic plane, a sailcraft in the inverse orbit exhibits a butterfly shape trajectory. As such, the new orbits are symmetrical with respect to a plane which contains the Sun-perihelion line. The relation of the sail attitude angles between the two symmetrical parts of the orbits are used to reduce the simulation effort. The quasi-heliostationary property at its aphelia is demonstrated with variation of the orbital radius. Evolutions of the orbital velocity and optimal sail orientations are also outlined and discussed to benefit future design work. As is suited for space observation guaranteed by its butterfly shape, the inverse orbits are thoroughly studied in terms of the concerned parameters. The discussion of the parametric influence is ranked in order as perihelion distance rE, required maximum position zmax, perihelion position zf and the sail lightness number β. Suitable ranges of each parameter are adopted to illustrate the orbital variation trend. Through numerical simulations the features of such inverse orbits are further emphasized to provide an initial reference for future researchers.

  • new applications of the h reversal trajectory using Solar Sails
    Research in Astronomy and Astrophysics, 2011
    Co-Authors: Xiangyuan Zeng, Hexi Baoyin, Shengping Gong
    Abstract:

    Advanced Solar sailing has been an increasingly attractive propulsion system for highly non-Keplerian orbits. Three new applications of the orbital angular momentum reversal (H-reversal) trajectories using Solar Sails are presented: space observation, heliocentric orbit transfer and collision orbits with asteroids. A theoretical proof for the existence of double H-reversal trajectories (referred to as ‘H2RTs’) is given, and the characteristics of the H2RTs are introduced before a discussion of the mission applications. A new family of H2RTs was obtained using a 3D dynamic model of the two-body frame. In a time-optimal control model, the minimum period H2RTs both inside and outside the ecliptic plane were examined using an ideal Solar sail. Due to the quasi-heliostationary property at its two symmetrical aphelia, the H2RTs were deemed suitable for space observation. For the second application, the heliocentric transfer orbit was able to function as the time-optimal H-reversal trajectory, since its perihelion velocity is a circular or elliptic velocity. Such a transfer orbit can place the sailcraft into a clockwise orbit in the ecliptic plane, with a high inclination or displacement above or below the Sun. The third application of the H-reversal trajectory was simulated impacting an asteroid passing near Earth in a head-on collision. The collision point can be designed through selecting different perihelia or different launch windows. Sample orbits of each application were presented through numerical simulation. The results can serve as a reference for theoretical research and engineering design.

Sood Rohan - One of the best experts on this subject based on the ideXlab platform.

  • Significance of Specific Force Models in Two Applications: Solar Sails to Sun-Earth L4/L5 and GRAIL Data Analysis Suggesting Lava Tubes and Buried Craters on the Moon
    'Purdue University (bepress)', 2016
    Co-Authors: Sood Rohan
    Abstract:

    In the trajectory design process, gravitational interaction between the bodies of interest plays a key role in developing the over-arching force model. However, non-gravitational forces, such as Solar radiation pressure (SRP), can significantly influence the motion of a spacecraft. Incorporating SRP within the dynamical model can assist in estimating the trajectory of a spacecraft with greater precision, in particular, for a spacecraft with a large area-to-mass ratio, i.e., Solar Sails. Subsequently, in the trajectory design process, Solar radiation pressure can be leveraged to maneuver the sail-based spacecraft. First, to construct low energy transfers, the invariant manifolds are explored that form an important tool in the computation and design of complex trajectories. The focus is the investigation of trajectory design options, incorporating Solar sail dynamics, from the Earth parking orbit to the vicinity of triangular Lagrange points. Thereafter, an optimization scheme assisted in investigating the ΔV requirement to depart from the Earth parking orbit. Harnessing the Solar radiation pressure, the spacecraft is delivered to the vicinity of the displaced Lagrange point and maintains a trajectory close to the artificial libration point with the help of the Solar sail. However, these trajectories are converged in a model formulated as a three-body problem with additional acceleration from Solar radiation pressure. Thus, the trajectories are transitioned to higher fidelity ephemeris model to account for additional perturbing accelerations that may dominate the sail-craft dynamics and improve upon the trajectory design process

  • Significance of specific force models in two applications: Solar Sails to sun-earth L4/L5 and grail data analysis suggesting lava tubes and buried craters on the moon
    'Purdue University (bepress)', 2016
    Co-Authors: Sood Rohan
    Abstract:

    In the trajectory design process, gravitational interaction between the bodies of interest plays a key role in developing the over-arching force model. However, non-gravitational forces, such as Solar radiation pressure (SRP), can significantly influence the motion of a spacecraft. Incorporating SRP within the dynamical model can assist in estimating the trajectory of a spacecraft with greater precision, in particular, for a spacecraft with a large area-to-mass ratio, i.e., Solar Sails. Subsequently, in the trajectory design process, Solar radiation pressure can be leveraged to maneuver the sail-based spacecraft. First, to construct low energy transfers, the invariant manifolds are explored that form an important tool in the computation and design of complex trajectories. The focus is the investigation of trajectory design options, incorporating Solar sail dynamics, from the Earth parking orbit to the vicinity of triangular Lagrange points. Thereafter, an optimization scheme assisted in investigating the ?V requirement to depart from the Earth parking orbit. Harnessing the Solar radiation pressure, the spacecraft is delivered to the vicinity of the displaced Lagrange point and maintains a trajectory close to the artificial libration point with the help of the Solar sail. However, these trajectories are converged in a model formulated as a three-body problem with additional acceleration from Solar radiation pressure. Thus, the trajectories are transitioned to higher fidelity ephemeris model to account for additional perturbing accelerations that may dominate the sail-craft dynamics and improve upon the trajectory design process. Alternatively, precise knowledge of the motion of a spacecraft about a central body and the contribution of the SRP can assist in deriving a highly accurate gravity field model. The high resolution gravity data can potentially assist in exploring the surface and subsurface properties of a particular body. With the goal of expanding human presence beyond Earth, sub-surface empty lava tubes on other worlds form ideal candidates for creating a permanent habitation environment safe from cosmic radiation, micrometeorite impacts and temperature extremes. In addition, gravitational analysis has also revealed large buried craters under thick piles of mare basalt, shedding light on Moon\u27s dynamic and hostile past. In this work, gravity mapping observations from NASA\u27s Gravity Recovery and Interior Laboratory (GRAIL) are employed to detect the presence of potential empty lava tubes and large impact craters buried beneath the lunar maria

Fanghua Jiang - One of the best experts on this subject based on the ideXlab platform.

  • Asteroid body-fixed hovering using nonideal Solar Sails
    Research in Astronomy and Astrophysics, 2015
    Co-Authors: Xiangyuan Zeng, Fanghua Jiang
    Abstract:

    The problem of body-fixed hovering over an asteroid using a compact form of nonideal Solar Sails with a controllable area is investigated. Nonlinear dynamic equations describing the hovering problem are constructed for a spherically symmetric asteroid. Numerical solutions of the feasible region for body-fixed hovering are obtained. Different sail models, including the cases of ideal, optical, parametric and Solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed. The required orientations for the sail and their corresponding variable lightness numbers are given for different hovering radii to identify the feasible region of the body-fixed hovering. An attractive scenario for a mission is introduced to take advantage of Solar sail hovering.

  • time optimal rendezvous transfer trajectory for restricted cone angle range Solar Sails
    Acta Mechanica Sinica, 2014
    Co-Authors: Fanghua Jiang
    Abstract:

    The advantage of Solar Sails in deep space exploration is that no fuel consumption is required. The heliocentric distance is one factor influencing the Solar radiation pressure force exerted on Solar Sails. In addition, the Solar radiation pressure force is also related to the Solar sail orientation with respect to the sunlight direction. For an ideal flat Solar sail, the cone angle between the sail normal and the sunlight direction determines the magnitude and direction of Solar radiation pressure force. In general, the cone angle can change from 0° to 90°. However, in practical applications, a large cone angle may reduce the efficiency of Solar radiation pressure force and there is a strict requirement on the attitude control. Usually, the cone angle range is restricted less more than an acute angle (for example, not more than 40°) in engineering practice. In this paper, the time-optimal transfer trajectory is designed over a restricted range of the cone angle, and an indirect method is used to solve the two point boundary value problem associated to the optimal control problem. Relevant numerical examples are provided to compare with the case of an unrestricted case, and the effects of different maximum restricted cone angles are discussed. The results indicate that (1) for the condition of a restricted cone-angle range the transfer time is longer than that for the unrestricted case and (2) the optimal transfer time increases as the maximum restricted cone angle decreases.

  • asteroid body fixed hovering using nonideal Solar Sails
    arXiv: Solar and Stellar Astrophysics, 2014
    Co-Authors: Xiangyuan Zeng, Fanghua Jiang
    Abstract:

    Asteroid body-fixed hovering problem using nonideal Solar sail models in a compact form with controllable sail area is investigated in this paper. The nonlinear dynamic equations for the hovering problem are constructed for a spherically symmetric asteroid. The feasible region for the body-fixed hovering is solved from the above equations by using a shooting method. The effect of the sail models, including the ideal, optical, parametric and Solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed in a parametric way. The required sail orientations and their corresponding variable lightness numbers are given for different hovering radii to identify the feasibility of the body-fixed hovering. An attractive mission scenario is introduced to enhance the advantage of the Solar sail hovering mission.