The International Astronautical Federation is the only professional society in the field of aerospace engineering and Sciences which brings together specialists of all countries interested in the exploration and peaceful exploitation of space. At its annual Congresses a large number of invited and/or carefully selected con tributed papers are presented which cover a wide variety of topics and are distributed over a number of sessions, each one being organized by two leading scientists who later chair the session itself. Each year the selection of specific topics to be dealt with. is dictated either by significant new progress achieved in some sectors or by new developments and trends which are liable to influence substantially the objectives toward which space research and/or application of space technology will be oriented in the immediate future. A second rigorous screening, performed with the help of the Session Chairmen and carried out according to the same criteria identifies finally the papers which are published in the Proceedings. The outcome of all this is reliable and authoritative information as to the actual status and future trends of space activities, both from the research point of view and from the point of view of u ilization and/or application."

Space scientists and engineers belonging to the professional societies associated with the International Astronautical Federation gathered together in Vienna to hold the Federation's 23rd Congress. A selected number of papers and critical surveys that were presented and debated at this Congress and which span the widely diversified field of astonautics are collected in the present Proceedings, together with a number of summaries of Round Table Discussions andjor Forum Sessions. As its predecessors in the series, Astronautical Research 1972 constitutes an indispensable reference for several groups of people: those who are actively engaged in astronautics; those who are interested in following and assessing, year by year, the developments in astronautics, its progress, its new directions in research; and those who are concerned with its many applications. Space science and technology are bound to play an increasing role in the immediate future, now that greater effort is being devoted to the exploitation of their relevance to other fields of human activity. Problems posed by the scarcity of earth resources and by their inadequate management, pollution problems, problems created by man's indiscriminate and often irresponsible action in vital sectors of the biosphere can be tackled and successfully alleviated, if not solved, by means of the soft and hard advanced technology developed for space systems.