This volume contains the detailed text of the major lectures and the abstracts of the lectures delivered during the seminar sessions. The subject of our NATO Advanced Study Institute in 1981 was the Application of Modern Dynamics to Celestial Mechanics and Astrodynamics. This Preface will first explain the terminology, then it will review shortly the content of the lectures and will outline how all this was made possible and, finally, it will disclose our future aspirations. Periodicity is an extremely important concept in our field, therefore, it should not be unexpected that our NATO Advanced Study Institute is enjoying a period of three years. Since 1972 we conducted four Institutes with increasing interest and en thusiasm displayed by the participants, lecturers and by this Director. Celestial Mechanics or Dynamical Astronomy is part of Astronomy dealing mostly with the motion of natural celestial bodies. Astrodynamics or Orbital Mechanics is the application of dynamics to problems of Space Engineering and it treats mostly the dynamical behavior of artificial satellites and space probes. The underlying mathematical and dynamical principles are, of course, the same for Celestial Mechanics and for Astrodynamics. This Director of the Institute and Editor of the Proceedings was extremely fortunate to have obtained the cooperation of out standing lecturers who were clear, thorough, understandable, patient to answer questions, but above all, had knowledge of the ix V. Szebehely (ed.). Applications of Modern Dynamics to Celestial Mechanics and Astrodynamics. ix-x.

This volume is designed as an introductory text and reference book for graduate students, researchers and practitioners in the fields of astronomy, astrodynamics, satellite systems, space sciences and astrophysics. The purpose of the book is to emphasize the similarities between celestial mechanics and astrodynamics, and to present recent advances in these two fields so that the reader can understand the inter-relations and mutual influences. The juxtaposition of celestial mechanics and astrodynamics is a unique approach that is expected to be a refreshing attempt to discuss both the mechanics of space flight and the dynamics of celestial objects. “Celestial Mechanics and Astrodynamics: Theory and Practice” also presents the main challenges and future prospects for the two fields in an elaborate, comprehensive and rigorous manner. The book presents homogenous and fluent discussions of the key problems, rendering a portrayal of recent advances in the field together with some basic concepts and essential infrastructure in orbital mechanics. The text contains introductory material followed by a gradual development of ideas interweaved to yield a coherent presentation of advanced topics.

In the last 20 years, researchers in the field of celestial mechanics have achieved spectacular results in their effort to understand the structure and evolution of our solar system. Modern Celestial Mechanics uses a solid theoretical basis to describe recent results on solar system dynamics, and it emphasizes the dynamics of planets and of small bodies. To grasp celestial mechanics, one must comprehend the fundamental concepts of Hamiltonian systems theory, so this volume begins with an explanation of those concepts. Celestial mechanics itself is then considered, including the secular motion of planets and small bodies and mean motion resonances. Graduate students and researchers of astronomy and astrophysics will find Modern Celestial Mechanics an essential addition to their bookshelves.

This volume of proceedings contains review and research papers concerning the impact of modern dynamics in astronomy. Modern dynamics is playing an increasing role in the solution of problems raised by astronomical observations. This new relationship is being fostered by discoveries of new systems, such as the Kuiper belt, pulsar and star companions; by progress in theoretical dynamics, like KAM and Nekhorochev theories and adiabatic invariants; and by the dissemination of fast computers. The two main areas of applications which are discussed are stellar systems, including dynamics of galaxies, and small bodies in the solar system. In both cases the concepts and tools of chaotic motion are considered and fully discussed.

Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documenta tion of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, compared to which our system of accumu lating abstracts for about six months offers the advantage of greater convenience for the user. Volume 31 contains literature published in 1982 and received before July 15, 1982; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English .

Methods in Astrodynamics and Celestial Mechanics is a collection of technical papers presented at the Astrodynamics Specialist Conference held in Monterey, California, on September 16-17, 1965, under the auspices of the American Institute of Aeronautics and Astronautics and Institute of Navigation. The conference provided a forum for tackling some of the most interesting applications of the methods of celestial mechanics to problems of space engineering. Comprised of 19 chapters, this volume first treats the promising area of motion around equilibrium configurations. Following a discussion on limiting orbits at the equilateral centers of libration, the reader is introduced to the asymptotic expansion technique and its application to trajectories. Asymptotic representations for solutions to the differential equations of satellite theory are considered. The last two sections deal with orbit determination and mission analysis and optimization in astrodynamics. Error equations of inertial navigation as applied to orbital determination and guidance are evaluated, along with parameter hunting procedures and nonlinear optimal control problems with control appearing linearly .This book will be useful to practitioners in the fields of aeronautics, astronautics, and astrophysics.