Design of Trajectory Optimization Approach for Space Maneuver Vehicle Skip Entry Problems

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Publisher : Springer
ISBN 13 : 9811398453
Total Pages : 207 pages
Book Rating : 4.8/5 (113 download)

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Book Synopsis Design of Trajectory Optimization Approach for Space Maneuver Vehicle Skip Entry Problems by : Runqi Chai

Download or read book Design of Trajectory Optimization Approach for Space Maneuver Vehicle Skip Entry Problems written by Runqi Chai and published by Springer. This book was released on 2019-07-30 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the design of optimal trajectories for space maneuver vehicles (SMVs) using optimal control-based techniques. It begins with a comprehensive introduction to and overview of three main approaches to trajectory optimization, and subsequently focuses on the design of a novel hybrid optimization strategy that combines an initial guess generator with an improved gradient-based inner optimizer. Further, it highlights the development of multi-objective spacecraft trajectory optimization problems, with a particular focus on multi-objective transcription methods and multi-objective evolutionary algorithms. In its final sections, the book studies spacecraft flight scenarios with noise-perturbed dynamics and probabilistic constraints, and designs and validates new chance-constrained optimal control frameworks. The comprehensive and systematic treatment of practical issues in spacecraft trajectory optimization is one of the book’s major features, making it particularly suited for readers who are seeking practical solutions in spacecraft trajectory optimization. It offers a valuable asset for researchers, engineers, and graduate students in GNC systems, engineering optimization, applied optimal control theory, etc.

Spacecraft Trajectory Optimization

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Publisher : Cambridge University Press
ISBN 13 : 113949077X
Total Pages : 313 pages
Book Rating : 4.1/5 (394 download)

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Book Synopsis Spacecraft Trajectory Optimization by : Bruce A. Conway

Download or read book Spacecraft Trajectory Optimization written by Bruce A. Conway and published by Cambridge University Press. This book was released on 2010-08-23 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a long-overdue volume dedicated to space trajectory optimization. Interest in the subject has grown, as space missions of increasing levels of sophistication, complexity, and scientific return - hardly imaginable in the 1960s - have been designed and flown. Although the basic tools of optimization theory remain an accepted canon, there has been a revolution in the manner in which they are applied and in the development of numerical optimization. This volume purposely includes a variety of both analytical and numerical approaches to trajectory optimization. The choice of authors has been guided by the editor's intention to assemble the most expert and active researchers in the various specialities presented. The authors were given considerable freedom to choose their subjects, and although this may yield a somewhat eclectic volume, it also yields chapters written with palpable enthusiasm and relevance to contemporary problems.

Advanced Trajectory Optimization, Guidance and Control Strategies for Aerospace Vehicles

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Publisher : Springer Nature
ISBN 13 : 9819943116
Total Pages : 272 pages
Book Rating : 4.8/5 (199 download)

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Book Synopsis Advanced Trajectory Optimization, Guidance and Control Strategies for Aerospace Vehicles by : Runqi Chai

Download or read book Advanced Trajectory Optimization, Guidance and Control Strategies for Aerospace Vehicles written by Runqi Chai and published by Springer Nature. This book was released on 2023-10-29 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the design and application of advanced trajectory optimization and guidance and control (G&C) techniques for aerospace vehicles. Part I of the book focuses on the introduction of constrained aerospace vehicle trajectory optimization problems, with particular emphasis on the design of high-fidelity trajectory optimization methods, heuristic optimization-based strategies, and fast convexification-based algorithms. In Part II, various optimization theory/artificial intelligence (AI)-based methods are constructed and presented, including dynamic programming-based methods, model predictive control-based methods, and deep neural network-based algorithms. Key aspects of the application of these approaches, such as their main advantages and inherent challenges, are detailed and discussed. Some practical implementation considerations are then summarized, together with a number of future research topics. The comprehensive and systematic treatment of practical issues in aerospace trajectory optimization and guidance and control problems is one of the main features of the book, which is particularly suitable for readers interested in learning practical solutions in aerospace trajectory optimization and guidance and control. The book is useful to researchers, engineers, and graduate students in the fields of G&C systems, engineering optimization, applied optimal control theory, etc.

Spacecraft Trajectory Optimization Using Many Embedded Lambert Problems

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)

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Book Synopsis Spacecraft Trajectory Optimization Using Many Embedded Lambert Problems by : David Ryan Ottesen

Download or read book Spacecraft Trajectory Optimization Using Many Embedded Lambert Problems written by David Ryan Ottesen and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improvement of spacecraft trajectory optimization approaches, methods, and techniques is critical for better mission design. Preliminary low-fidelity analysis precedes high-fidelity analysis to efficiently explore the space of a problem. The work of this dissertation extends an embedded boundary value problem (EBVP) technique for preliminary design in the two-body problem. The EBVP technique is designed for direct, unconstrained optimization using many, short-arc, embedded Lambert problems that discretize the trajectory. The short arcs share terminal positions to implicitly enforce position continuity and the instantaneous velocity discontinuities in between segments are the control. These coasting arcs and impulsive maneuvers in between segments are defined collectively as a coast-impulse model, similar to the well-known Sims-Flanagan model. Use of EBVPs is not new to spacecraft trajectory optimization, extensively used in primer vector theory, flyby-tour design, direct impulsive-maneuver optimization, and more. Lack of fast and accurate BVP solvers has prevented the use of the EBVP technique on problems with more than dozens of segments. For the two-body problem, a recently-developed Lambert solver, complete with the necessary partials, enables the extension of the EBVP technique to many hundreds to thousands of segments and hundreds of revolutions. The use of many short arcs guarantees existence and uniqueness for the Lambert problem of each segment. Furthermore, short arcs simultaneously approximate low thrust and eliminates the need to know the structure of a high-thrust impulsive-maneuver solution. A set of examples show the EBVP technique to be efficient, robust, and useful. In particular, an example using 256 revolutions, 6143 segments, and a constant flight time per segment, optimizes in 5.5 hours using a single processor. After this initial demonstration, the EBVP technique is improved by a function which enables variable flight time per segment. Guided by the well-known Sundman transformation, these piecewise Sundman transformation (PST) functions divide the total flight time of the trajectory into spatially-even arcs, importantly not modifying the dynamics. Flight-time functions and their dynamical regularization counterpart are shown to share similar behavior for Keplerian orbit propagation. The PST functions are also shown to extend the EBVP technique to a large design space, where a runtime-feasible transfer with 512 revs and 12287 segments is presented that significantly changes semimajor axis, eccentricity, and inclination. Moreover, another example is presented that transfers through the numerically challenging parabolic boundary, i.e. a transfer from a circular to hyperbolic orbit. Both these examples use an exponent of 3/2 for the PST to enforce the spatially-even arcs or equal steps in eccentric anomaly. Lastly, an optimal control problem is formulated to solve a class of many-revolution trajectories relevant to the EBVP technique. For transfers that minimize thrust-acceleration-squared, primer vector theory enables the mapping of direct, many-impulsive-maneuver trajectories to the indirect, continuous-thrust-acceleration equivalent. The mapping algorithm is independent of how the direct solution is obtained and the mapping computations only require a solver for a BVP and its partial derivatives. For the two-body problem, a Lambert solver is used. The mapping is simple because the impulsive maneuvers and co-states share the same linear space around an optimal trajectory. For numerical results, the direct coast-impulse solutions are demonstrated to converge to the indirect continuous solutions as the number of impulses and segments increase. The two-body design space is explored with a set of three many-revolution, many-segment examples changing semimajor axis, eccentricity, and inclination. The first two examples change either a small amount of semimajor axis or eccentricity, and the third example is a transfer to geosynchronous orbit. Using a single processor, the optimization runtime is seconds to minutes for revolution counts of 10 to 100, while on the order of one hour for examples with up to 500 revolutions. Any of these thrust-acceleration-squared solutions are good candidates to start a homotopy to a higher-fidelity minimization problem with practical constraints

Trajectory Optimization for an Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return

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Publisher :
ISBN 13 :
Total Pages : 50 pages
Book Rating : 4.:/5 (31 download)

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Book Synopsis Trajectory Optimization for an Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return by : John W. Young

Download or read book Trajectory Optimization for an Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return written by John W. Young and published by . This book was released on 1967 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Trajectory Optimization and Guidance Methods for Mars Entry

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Publisher : Springer Nature
ISBN 13 : 981996282X
Total Pages : 297 pages
Book Rating : 4.8/5 (199 download)

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Book Synopsis Trajectory Optimization and Guidance Methods for Mars Entry by : Shuang Li

Download or read book Trajectory Optimization and Guidance Methods for Mars Entry written by Shuang Li and published by Springer Nature. This book was released on with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt:

A Combined Global and Local Methodology for Launch Vehicle Trajectory Design-space Exploration and Optimization

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (89 download)

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Book Synopsis A Combined Global and Local Methodology for Launch Vehicle Trajectory Design-space Exploration and Optimization by : Michael J. Steffens

Download or read book A Combined Global and Local Methodology for Launch Vehicle Trajectory Design-space Exploration and Optimization written by Michael J. Steffens and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Trajectory optimization is an important part of launch vehicle design and operation. With the high costs of launching payload into orbit, every pound that can be saved increases affordability. One way to save weight in launch vehicle design and operation is by optimizing the ascent trajectory. Launch vehicle trajectory optimization is a field that has been studied since the 1950's. Originally, analytic solutions were sought because computers were slow and inefficient. With the advent of computers, however, different algorithms were developed for the purpose of trajectory optimization. Computer resources were still limited, and as such the algorithms were limited to local optimization methods, which can get stuck in specific regions of the design space. Local methods for trajectory optimization have been well studied and developed. Computer technology continues to advance, and in recent years global optimization has become available for application to a wide variety of problems, including trajectory optimization. The aim of this thesis is to create a methodology that applies global optimization to the trajectory optimization problem. Using information from a global search, the optimization design space can be reduced and a much smaller design space can be analyzed using already existing local methods. This allows for areas of interest in the design space to be identified and further studied and helps overcome the fact that many local methods can get stuck in local optima. The design space included in trajectory optimization is also considered in this thesis. The typical optimization variables are initial conditions and flight control variables. For direct optimization methods, the trajectory phase structure is currently chosen a priori. Including trajectory phase structure variables in the optimization process can yield better solutions. The methodology and phase structure optimization is demonstrated using an earth-to-orbit trajectory of a Delta IV Medium launch vehicle. Different methods of performing the global search and reducing the design space are compared. Local optimization is performed using the industry standard trajectory optimization tool POST. Finally, methods for varying the trajectory phase structure are presented and the results are compared.

A Reinforcement Learning Approach to Spacecraft Trajectory Optimization

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Publisher :
ISBN 13 :
Total Pages : 69 pages
Book Rating : 4.:/5 (117 download)

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Book Synopsis A Reinforcement Learning Approach to Spacecraft Trajectory Optimization by : Daniel S. Kolosa

Download or read book A Reinforcement Learning Approach to Spacecraft Trajectory Optimization written by Daniel S. Kolosa and published by . This book was released on 2019 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation explores a novel method of solving low-thrust spacecraft targeting problems using reinforcement learning. A reinforcement learning algorithm based on Deep Deterministic Policy Gradients was developed to solve low-thrust trajectory optimization problems. The algorithm consists of two neural networks, an actor network and a critic network. The actor approximates a thrust magnitude given the current spacecraft state expressed as a set of orbital elements. The critic network evaluates the action taken by the actor based on the state and action taken. Three different types of trajectory problems were solved, a generalized orbit change maneuver, a semimajor axis change maneuver, and an inclination change maneuver. When training the algorithm in a simulated space environment, it was able to solve both the generalized orbit change and semimajor axis change maneuvers with no prior knowledge of the environment’s dynamics. The robustness of the algorithm was tested on an inclination change maneuver with a randomized set of initial states. After training, the algorithm was able to successfully generalize and solve new inclination changes that it has not seen before. This method has potential future applications in developing more complex low-thrust maneuvers or real-time autonomous spaceflight control.

Analytical Investigations in Aircraft and Spacecraft Trajectory Optimization and Optimal Guidance

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Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781722945305
Total Pages : 188 pages
Book Rating : 4.9/5 (453 download)

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Book Synopsis Analytical Investigations in Aircraft and Spacecraft Trajectory Optimization and Optimal Guidance by : National Aeronautics and Space Administration (NASA)

Download or read book Analytical Investigations in Aircraft and Spacecraft Trajectory Optimization and Optimal Guidance written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of analytical studies is presented related to unconstrained and constrained aircraft (a/c) energy-state modeling and to spacecraft (s/c) motion under continuous thrust. With regard to a/c unconstrained energy-state modeling, the physical origin of the singular perturbation parameter that accounts for the observed 2-time-scale behavior of a/c during energy climbs is identified and explained. With regard to the constrained energy-state modeling, optimal control problems are studied involving active state-variable inequality constraints. Departing from the practical deficiencies of the control programs for such problems that result from the traditional formulations, a complete reformulation is proposed for these problems which, in contrast to the old formulation, will presumably lead to practically useful controllers that can track an inequality constraint boundary asymptotically, and even in the presence of 2-sided perturbations about it. Finally, with regard to s/c motion under continuous thrust, a thrust program is proposed for which the equations of 2-dimensional motion of a space vehicle in orbit, viewed as a point mass, afford an exact analytic solution. The thrust program arises under the assumption of tangential thrust from the costate system corresponding to minimum-fuel, power-limited, coplanar transfers between two arbitrary conics. The thrust program can be used not only with power-limited propulsion systems, but also with any propulsion system capable of generating continuous thrust of controllable magnitude, and, for propulsion types and classes of transfers for which it is sufficiently optimal the results of this report suggest a method of maneuvering during planetocentric or heliocentric orbital operations, requiring a minimum amount of computation; thus uniquely suitable for real-time feedback guidance implementations. Markopoulos, Nikos and Calise, Anthony J. Unspecified Center AIRCRAFT GUIDANCE; CONTROLLERS; FLIGHT PATHS; OPTIMAL CONTROL...

Trajectory Optimization for an Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return

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Publisher :
ISBN 13 :
Total Pages : 52 pages
Book Rating : 4.:/5 (317 download)

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Book Synopsis Trajectory Optimization for an Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return by :

Download or read book Trajectory Optimization for an Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return written by and published by . This book was released on 1967 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Low Thrust Space Vehicle Trajectory Optimization Using Regularized Variables

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Publisher :
ISBN 13 :
Total Pages : 44 pages
Book Rating : 4.:/5 (317 download)

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Book Synopsis Low Thrust Space Vehicle Trajectory Optimization Using Regularized Variables by : K. J. Schwenzfeger

Download or read book Low Thrust Space Vehicle Trajectory Optimization Using Regularized Variables written by K. J. Schwenzfeger and published by . This book was released on 1974 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimizing the trajectory of a low thrust space vehicle usually means solving a nonlinear two point boundary value problem. In general, accuracy requirements necessitate extensive computation times. In celestial mechanics, regularizing transformations of the equations of motion are used to eliminate computational and analytical problems that occur during close approaches to gravitational force centers. It was shown in previous investigations that regularization in the formulation of the trajectory optimization problem may reduce the computation time. In this study, a set of regularized equations describing the optimal trajectory of a continuously thrusting space vehicle is derived. The computational characteristics of the set are investigated and compared to the classical Newtonian unregularized set of equations. The comparison is made for low thrust, minimum time, escape trajectories and numerical calculations of Keplerian orbits. The comparison indicates that in the cases investigated for bad initial guesses of the known boundary values a remarkable reduction in the computation time was achieved. Furthermore, the investigated set of regularized equations shows high numerical stability even for long duration flights and is less sensitive to errors in the guesses of the unknown boundary values.

A General Branched Trajectory Optimization Algorithm with Applications to Space Shuttle Vehicle Mission Design

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Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (14 download)

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Book Synopsis A General Branched Trajectory Optimization Algorithm with Applications to Space Shuttle Vehicle Mission Design by : H. L. Rozendaal

Download or read book A General Branched Trajectory Optimization Algorithm with Applications to Space Shuttle Vehicle Mission Design written by H. L. Rozendaal and published by . This book was released on 1971 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Trajectory Optimization for the National Aerospace Plane

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Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781722912598
Total Pages : 46 pages
Book Rating : 4.9/5 (125 download)

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Book Synopsis Trajectory Optimization for the National Aerospace Plane by : National Aeronautics and Space Administration (NASA)

Download or read book Trajectory Optimization for the National Aerospace Plane written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-13 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this research is to develop an efficient and robust trajectory optimization tool for the optimal ascent problem of the National Aerospace Plane (NASP). This report is organized in the following order to summarize the complete work: Section two states the formulation and models of the trajectory optimization problem. An inverse dynamics approach to the problem is introduced in Section three. Optimal trajectories corresponding to various conditions and performance parameters are presented in Section four. A midcourse nonlinear feedback controller is developed in Section five. Section six demonstrates the performance of the inverse dynamics approach and midcourse controller during disturbances. Section seven discusses rocket assisted ascent which may be beneficial when orbital altitude is high. Finally, Section eight recommends areas of future research. Lu, Ping Unspecified Center NAG1-1255...

Singular Perturbation Analysis of Aotv-Related Trajectory Optimization Problems

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Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781722741037
Total Pages : 54 pages
Book Rating : 4.7/5 (41 download)

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Book Synopsis Singular Perturbation Analysis of Aotv-Related Trajectory Optimization Problems by : National Aeronautics and Space Administration (NASA)

Download or read book Singular Perturbation Analysis of Aotv-Related Trajectory Optimization Problems written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-10 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of real time guidance and optimal control of Aeroassisted Orbit Transfer Vehicles (AOTV's) was addressed using singular perturbation theory as an underlying method of analysis. Trajectories were optimized with the objective of minimum energy expenditure in the atmospheric phase of the maneuver. Two major problem areas were addressed: optimal reentry, and synergetic plane change with aeroglide. For the reentry problem, several reduced order models were analyzed with the objective of optimal changes in heading with minimum energy loss. It was demonstrated that a further model order reduction to a single state model is possible through the application of singular perturbation theory. The optimal solution for the reduced problem defines an optimal altitude profile dependent on the current energy level of the vehicle. A separate boundary layer analysis is used to account for altitude and flight path angle dynamics, and to obtain lift and bank angle control solutions. By considering alternative approximations to solve the boundary layer problem, three guidance laws were derived, each having an analytic feedback form. The guidance laws were evaluated using a Maneuvering Reentry Research Vehicle model and all three laws were found to be near optimal. For the problem of synergetic plane change with aeroglide, a difficult terminal boundary layer control problem arises which to date is found to be analytically intractable. Thus a predictive/corrective solution was developed to satisfy the terminal constraints on altitude and flight path angle. A composite guidance solution was obtained by combining the optimal reentry solution with the predictive/corrective guidance method. Numerical comparisons with the corresponding optimal trajectory solutions show that the resulting performance is very close to optimal. An attempt was made to obtain numerically optimized trajectories for the case where heating rate is constrained. A first order state variable inequality constra...

Trajectory Optimization for Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return [with List of References]

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Publisher :
ISBN 13 :
Total Pages : 39 pages
Book Rating : 4.:/5 (979 download)

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Book Synopsis Trajectory Optimization for Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return [with List of References] by :

Download or read book Trajectory Optimization for Apollo-type Vehicle Under Entry Conditions Encountered During Lunar Return [with List of References] written by and published by . This book was released on 1967 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Design and Optimization of Body-to-body Impulsive Trajectories in Restricted Four-body Models

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ISBN 13 :
Total Pages : 386 pages
Book Rating : 4.:/5 (776 download)

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Book Synopsis Design and Optimization of Body-to-body Impulsive Trajectories in Restricted Four-body Models by : Fady Michel Morcos

Download or read book Design and Optimization of Body-to-body Impulsive Trajectories in Restricted Four-body Models written by Fady Michel Morcos and published by . This book was released on 2010 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spacecraft trajectory optimization is a topic of crucial importance to space missions design. The less fuel required to accomplish the mission, the more payload that can be transported, and the higher the opportunity to lower the cost of the space mission. The objective is to find the optimal trajectory through space that will minimize the fuel used, and still achieve all mission constraints. Most space trajectories are designed using the simplified relative two-body problem as the base model. Using this patched conics approximation, however, constrains the solution space and fails to produce accurate initial guesses for trajectories in sensitive dynamics. This dissertation uses the Circular Restricted Three-Body Problem (CR3BP) as the base model for designing transfer trajectories in the Circular Restricted Four-Body Problem (CR4BP). The dynamical behavior of the CR3BP guides the search for useful low-energy trajectory arcs. Two distinct models of the CR4BP are considered in this research: the Concentric model, and the Bi-Circular model. Transfers are broken down into trajectory arcs in two separate CR3BPs and the stable and unstable manifold structures of both systems are utilized to produce low-energy transfer arcs that are later patched together to form the orbit-to-orbit transfer. The patched solution is then used as an initial guess in the CR4BP model. A vital contribution of this dissertation is the sequential process for initial guess generation for transfers in the CR4BP. The techniques discussed in this dissertation overcome many of the difficulties in the trajectory design process presented by the complicated dynamics of the CR4BP. Indirect optimization techniques are also used to derive the first order necessary conditions for optimality to assure the optimality of the transfers and determine whether additional impulses might further lower the total cost of the mission.

Analysis and Design of Propulsive Guidance for Atmospheric Skip Entry Trajectories

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Publisher :
ISBN 13 :
Total Pages : 164 pages
Book Rating : 4.:/5 (668 download)

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Book Synopsis Analysis and Design of Propulsive Guidance for Atmospheric Skip Entry Trajectories by : Garrett Oliver Teahan

Download or read book Analysis and Design of Propulsive Guidance for Atmospheric Skip Entry Trajectories written by Garrett Oliver Teahan and published by . This book was released on 2006 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the ability to use propulsive guidance for atmospheric skip entry trajectories was completed. The analysis centered itself around the proposed design of NASA's Crew Exploration Vehicle. The primary aerodynamic guidance system must execute an atmospheric skip maneuver when attempting to reach distant landing sites. These maneuvers result in the loss of aerodynamic control authority during the skip phase. The physics of the problem were studied through an analysis of the minimum impulsive AV. This analysis was completed for a number of different trajectories with varying energies. The framework of the propulsive guidance algorithm, derived from the Powered Explicit Guidance law of the Space Shuttle, was presented and the augmented design was explained. The sensitivity of the propulsive guidance solution to a given trajectory was explored as well as its response to altitude constrained maneuverability. The robustness of the algorithm is measured using Monte Carlo techniques. The results showed that the current design of the Crew Exploration Vehicle and the current implementation of the primary aerodynamic guidance system are inadequate for a precise, long range, crewed return from the Moon. It was also shown that the lower energy trajectories are more favorable given the altitude reorientation constraint. It was recommended that the skip phase be redefined such that it does not begin until the altitude reorientation constraint is met. It was shown that a combination of increasing the total amount of thrust available, AV allowance, and the entry guidance precision are necessary to bring the success rate to acceptable levels for a precise, long range, crewed return from the Moon.