Download or read book Improved Initial Value Estimates for Minimum fuel Orbital Transfers written by Daniel Edward Gill (CAPT, USAF.) and published by . This book was released on 1969 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improved Initial Value Estimates for Minimum Fuel Orbital Transfers written by Daniel E. Gill and published by . This book was released on 1969 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is developed for computing improved initial-value estimates for minimum-fuel transfer trajectories between coplanar, elliptic orbits with a thrust-limited, variable-mass rocket moving in an inverse square-law gravitational field. The initial and final orbits are specified by their eccentricities, semilateral recta and arguments of pericenter and the entire transfer consists of two finite-thrust phases. Estimates for the parameters of the optimal transfer trajectory are provided by the two-impulse solution and the techniques presented in this study provide good estimates for the unknown initial values of unspecified control, state and adjoint variables which are required to successfully compute the minimum-fuel transfer trajectory between specified orbits. (Author).

Download or read book A Collection of Technical Papers written by and published by . This book was released on 1969 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book MINIMUM FUEL THRUST LIMITED TRANSFER TRAJECTORIES BETWEEN COPLANAR ELLIPTIC ORBITS written by Edward Adolph Kern and published by . This book was released on 1968 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is developed for the efficient computation of minimum-fuel transfer trajectories between coplanar elliptic orbits with a thrust-limited variable-mass rocket moving in a central gravitation force field. Each orbit is defined through the eccentricity, semi-latus rectum, and argument of pericenter. Transfer time is left open. The minimum-fuel trajectory is assumed to consist of two thrusting phases separated by a coasting phase. Computation of the minimum-fuel transfer trajectory is accomplished by a direct integration of the rocket equations of motion and the associated adjoint equations which are developed from variational calculus techniques. This direct approach is made possible by a unique transformation of the adjoint equations into a set of equations which provide a much better understanding of the general behavior of minimum-fuel transfer trajectories. Reasonable estimates of the thrusting interval durations, initial thrust angle, and initial true anomaly are derived from the corresponding minimum-fuel, two-impulse transfer trajectory. The initial value of a newly discovered variable is used in conjunction with the initial thrust angle to obtain the thrusting interval durations specified by the two-impulse transfer. (Author).

Download or read book Minimum fuel Transfers Between Coaxial Orbits Both Coplanar and Concoplanar written by Stanford University. Department of Aeronautics and Astronautics and published by . This book was released on 1967 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Minimum Fuel Continuous Low Thrust Orbital Transfer written by Eugene A. Smith and published by . This book was released on 1974 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Minimum fuel continuous low thrust orbit transfer is an optimal control problem which requires the application of iterative numerical methods to solve the resulting two point boundary value problem. A combination gradient- neighboring extremal algorithm gives accurate results when both the initial and terminal orbits are coplanar. These results are then used to extend the problem to include out-of-plane transfers between orbits of widely varying inclination. Control histories, in terms of thrust direction, are plotted as a function of time for both coplanar and non-coplanar transfers. Steering programs for coplanar transfers are characterized by a rapid thrust reversal which is dependent on eccentricity for the time of its occurrence. In the latter case, out-of-plane thrusting is primarily a function of the inclination change between orbits. On the basis of these results, the particular numerical approach used provides an effective method for generating optimal low thrust orbital transfer guidance.

Download or read book Master s Theses and Doctoral Dissertations in the Pure and Applied Sciences written by and published by . This book was released on 1970 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fuel Optimal Trajectories of Aeroassisted Orbital Transfer with Plane Change written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-07 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of minimization of fuel consumption during the atmospheric portion of an aeroassisted, orbital transfer with plane change is addressed. The complete mission has required three characteristic velocities, a deorbit impulse at high earth orbit (HEO), a boost impulse at the atmospheric exit, and a reorbit impulse at low earth orbit (LEO). A performance index has been formulated as the sum of these three impulses. Application of optimal control principles has led to a nonlinear, two-point, boundary value problem which was solved by using a multiple shooting algorithm. The strategy for the atmospheric portion of the minimum-fuel transfer is to start initially with the maximum positive lift in order to recover from the downward plunge, and then to fly with a gradually decreasing lift such that the vehicle skips out of the atmosphere with a flight path angle near zero degrees. Naidu, Desineni Subbaramaiah and Hibey, Joseph L. Unspecified Center...

Download or read book Optimum Low Thrust Elliptic Orbit Transfer Using Numerical Averaging written by Zahi Bassem Tarzi and published by . This book was released on 2012 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-thrust electric propulsion is increasingly being used for spacecraft missions primarily due to its high propellant efficiency. Since analytical solutions for general low-thrust transfers are not available, a simple and fast method for low-thrust trajectory optimization is of great value for preliminary mission planning. However, few low-thrust trajectory tools are appropriate for preliminary mission design studies. The method presented in this paper provides quick and accurate solutions for a wide range of transfers by using numerical orbital averaging to improve solution convergence and include orbital perturbations. Thus allowing preliminary trajectories to be obtained for transfers which involve many revolutions about the primary body. This method considers minimum fuel transfers using first order averaging to obtain the fuel optimum rates of change of the equinoctial orbital elements in terms of each other and the Lagrange multipliers. Constraints on thrust and power, as well as minimum periapsis, are implemented and the equations are averaged numerically using a Gaussian quadrature. The use of numerical averaging allows for more complex orbital perturbations to be added without great difficulty. Orbital perturbations due to solar radiation pressure, atmospheric drag, a non-spherical central body, and third body gravitational effects have been included. These perturbations have not ben considered by previous methods using analytical averaging. Thrust limitations due to shadowing have also been considered in this study. To allow for faster convergence of a wider range of problems, the solution to a transfer which minimizes the square of the thrust magnitude is used as a preliminary guess for the minimum fuel problem. Thus, this method can be quickly applied to many different types of transfers which may include various perturbations. Results from this model are shown to provide a reduction in propellant mass required over previous minimum fuel solutions. Minimum time transfers are also solved and compared to minimum fuel.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Minimum fuel Orbital Transfer Using Finite Thrust written by Jerry L. Mrozek (CAPT, USAF.) and published by . This book was released on 1975 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Minimum Time and Fuel Trajectories for Orbital Transfer written by Stuart Gerald Greenberg and published by . This book was released on 1966 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Minimum fuel Orbital Transfers with Low thrust Rockets written by Y. Genin and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Orbital Transfer with Minimum Fuel written by Willard Evan Bleick and published by . This book was released on 1963 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extension is made of the problem of scheduling the direction p of constant momentum thrust of a rocket, which loses mass at a constant rate, so that it transfers to a known earth satellite orbit in minimum time T after launching. A numerical solution was obtained, using rectangular coordinates, for the case of fixed launching conditions. The method is extended to solve the problem of orbital transfer of such a rocket with minimum fuel consumption. (Author).

Download or read book Orbital Mechanics for Engineering Students written by Howard D. Curtis and published by Elsevier. This book was released on 2009-10-26 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orbital Mechanics for Engineering Students, Second Edition, provides an introduction to the basic concepts of space mechanics. These include vector kinematics in three dimensions; Newton's laws of motion and gravitation; relative motion; the vector-based solution of the classical two-body problem; derivation of Kepler's equations; orbits in three dimensions; preliminary orbit determination; and orbital maneuvers. The book also covers relative motion and the two-impulse rendezvous problem; interplanetary mission design using patched conics; rigid-body dynamics used to characterize the attitude of a space vehicle; satellite attitude dynamics; and the characteristics and design of multi-stage launch vehicles. Each chapter begins with an outline of key concepts and concludes with problems that are based on the material covered. This text is written for undergraduates who are studying orbital mechanics for the first time and have completed courses in physics, dynamics, and mathematics, including differential equations and applied linear algebra. Graduate students, researchers, and experienced practitioners will also find useful review materials in the book. - NEW: Reorganized and improved discusions of coordinate systems, new discussion on perturbations and quarternions - NEW: Increased coverage of attitude dynamics, including new Matlab algorithms and examples in chapter 10 - New examples and homework problems

Download or read book Investigation of Minimum Fuel Limited Thrust Orbital Transfer Trajectories written by Harold Dean Childers and published by . This book was released on 1969 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The method of quasilinearization is applied to the solution of a system of lumped-parameter differential equations providing the necessary conditions for minimum-fuel finite-thrust transfers between coplanar orbits. A central gravitational field is assumed. The equations are derived from the basic equations describing the motion of a finite-thrust rocket. The method of optimization (a modification of quasilinearization for application to bang-bang control problems), and the computer program used to solve the problem are discussed. The method is found to be inapplicable to the problem as originally formulated, and reasons for the inapplicability are given. A new formulation is presented, and computer programming techniques relevant to its solution are discussed. A printout of the program is included. (Author).