The National Aeronautics; and Space Act defined the national effort in the exploration of space-the largest, most complex research and development effort ever undertaken. It also provided for the continuation of the long tradition of research in aeronautics begun under the National Advisory Committee for Aeronautics. During the past five years, an immense effort has been set in motion. That this effort has borne fruit is evidenced by the events of the years since the passage of the Act, some of which are recorded in the pages that follow. These events constitute at least a partial record of the raw material which is giving shape to the space effort. In some instances, they represent the growth of space technology and equipment: improvement in the percentage of successful launches; the development of large boosters capable of supporting larger payloads in more complex missions. The overall increases in reliability, sensitivity, and accuracy of equipment are all signs of the increasing breadth and depth of our knowledge of the requirements for space flight. In other instances, these events portray our increasing capacity to explore both the near and far reaches of space and to benefit from knowledge gained by exploration. Though our knowledge has increased at a dramatic rate, the demand for new information-which has become such a pressing demand for practical reasons, for defense purposes, and as part and parcel of the persistent human drive to know-threatens constantly to outstrip the supply. The wide range of events recorded here portray the wide scope of this tremendous scientific undertaking. But perhaps even more indicative than the variety of events, is the broad social, economic, and political impact of the many projects and programs. For instance, Professor Frederic Seitz, President of the National Academy of Sciences, said recently that there was no part of university activity related to science and technology "which is not involved in fundamental way in the space effort." Or, in another field, we note that by the end of 1963, some 65 political entities were cooperating in our international space program.This chronology of the sixth year of the space age was prepared from open public sources. Like its annual ancestors, it was intended to provide a compilation of known events related to the scientific, technological, organization, and policy aspects of space exploration and exploitation. Although its index is a ready vehicle for informational reentry it was not conceived as historical assessment. It provides a comprehensive listing of the growing welter of events in their own date and place. The pace and complexity of the challenging and sometimes dramatic endeavor as man learns and masters nature beyond planet Earth is at least chronicled in a useful form. Hopefully, it provides some of the much-needed perspective for most readers, many of whom are undoubtedly as breathless as contemporary historians.