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• Establish clear lines of responsibility for the
appropriate governmental agencies. Assign NASA
implementing the ground, environmental and
comparative systems work necessary to make a good
technical evaluation of this system at that time
Developing the PTM is a very specific recommendation for the next step in our country's space program and certainly is not intended to be totally comprehensive of all that should be done in space. Solar Power Satellite Technology Development
is a program which I believe will provide fresh impetus and enthusiasm within the space community. We will be using the Shuttle and space technology to perform a mission of great value to all of us here on Earth. This is my recommendation
for the next step in our country's space program
Power Satellite Technology program.
Center for Astrophysics
60 Garden Street
Cambridge, Massachusetts 02138
January 23, 1978
The Hon. Olin E. Teague, Chairman
Suite 2321 Rayburn House Office Bldg.
Harvard College Observatory
Dear Mr. Teague:
This will acknowledge your letter of December 19, 1977 requesting my
I welcome the opportunity to participate and enclose a paper which I hope
Please do not hesitate to call on me if you should require further information.
Riccardo Giacconi, Professor of Astronomy,
Associate Director, High Energy Astrophysics Division,
A CROSSROADS IN THE AMERICAN SPACE PROGRAM
Harvard-Smithsonian Center for Astrophysics
The space program of the United States hardly requires any new justification here. Every consideration of the alarming trends that threaten our environment here on Earth leads at once to the necessity for continuing our exploration and exploitation of space over the next few decades. As this environment deteriorates and shrinks around us, space provides our last hope to insure raw materials and living room for an ever more demanding and increasing world population. Activity in space is thus a partner to a far-sighted effort to preserve our environment here on Earth.
Moreover, the space program can itself enhance this partnership by providing a significant cutting edge for technological advances, which benefit both space and terrestrial activities. In the last decade, unfortunately, short-sighted fiscal policies have led to a partial dismantling of the research-and-development base which has given the United States its current technological supremacy in science, trade, and defense; both public and private sectors continue to drain our scientific and technological base without apparent thought for the future. A renewed commitment to extensive space activity would be of great help in reversing this trend.
What direction should this renewed commitment take? In answering this question, it is important to recognize that the United States now stands at a crossroads in its space program. The era of expendable, one-shot launch vehicles will soon be behind us; we now stand on the threshold of the Space Shuttle era, in which a Space Transportation System (STS), developed at a cost of over $8 billion in public funds, will permit the delivery of massive payloads to near-Earth orbit on a regularly scheduled basis. Clearly, planning for space activity in the next decade should not be guided by ideas from the rocket era, but rather should be aimed at capitalizing on the enormous investment already made in the Shuttle program and at making most effective use of the Shuttle capabilities.
By its very design, the Shuttle can bring up to orbit heavier payloads than it can return to Earth. Thus, the Shuttle-implemented STS is ideally suited for the assembling of materials in near-Earth orbit. This fact suggests strongly that the construction of a Shuttle base, or space station, should receive high priority during the coming phase of space exploration.
First of all, such a base would obviously furnish a desirable point of rendezvous for Shuttle flights themselves. For example, the base could be stocked with appropriate supplies and provide Shuttle repair and service, in addition to providing a storage ocale for materials brought into orbit by STS.
Such a base would also enhance prospects for exploitation of space in the fields of communication, Earth-resources monitoring, and energy generation, activities which appear to be best undertaken from a near-Earth platform rather than from deep space. Human participation in such activities will require that man be able to operate effectively in space for extended periods of time. A space station could provide permanent living quarters for men in space under much more desirable conditions than those characterizing an individual Shuttle flight and could more conveniently support a program of research into the effects of long-term space habitation. Concurrently, space-station inhabitants could be carrying our activities relating to those important practical mission goals mentioned above.
The base would, in addition, provide a rational and economical point of departure for space flights to far-Earth orbit or to other parts of the Solar System. Space vehicles carried to the base by the Shuttle, or constructed there from Shuttlesupplied components, could be designed without the burdensome aerodynamic constraints that shape the structure of vehicles launched from the Earth's surface. The economies permitted by this approach to the launch of space vehicles to more distant targets could prove significant in plans to acquire raw materials from the Moon or from Earth-crossing asteroids.
Finally, such a Shuttle base would provide an enormous enhancement of our capabilities for research in space science. We must remember that the scientific returns from the American space program have constituted one of its greatest benefits to date. Through the space program, we have learned a great deal about our own atmosphere, ionosphere, and magnetosphere. We have begun to understand the relation between solar and terrestrial phenomena, particularly those occurring through the medium of the solar wind. Comparative studies of the atmospheres, of the physical and chemical surface properties, and of the histories of different bodies in the Solar System promise to offer clues to the origin and necessary equilibrium of the conditions that nurture life here on Earth.
However, among scientific disciplines, one of the greatest beneficiaries has certainly been astronomy, that oldest of sciences now becoming a prodigy of the space age. It is as if a veil that prevented us from seeing the heavens in all their splendor had been torn away from our eyes. For the first time in human history, we can now see celestial objects in every range of emitted radiation wavelengths. The study of the Universe in the gamma-ray, X-ray, ultraviolet, and infrared regions of the electromagnetic spectrum, which are inaccessible from the ground, is yielding a continuous stream of spectacular and unexpected discoveries.
In the new branch of astronomy with which I am personally involved - X-ray Astronomy the past fifteen years have brought us from the discovery of the first X-ray sources outside the Solar System to knowledge of a host of phenomena displaying energy release on a titanic scale: binary-star X-ray sources, neutron stars and "black holes" in binary systems, and powerful X-ray emission from active galaxies of all types, including quasars, believed to be the most distant objects in the Universe. The recent discovery that hot gas at a temperature of 100 million degrees pervades the space in
clusters of galaxies reveals a previously unknown component of the Universe whose mass is equal to that previously known to exist in optically visible objects. The
impact of these discoveries, and of those made at other wavelengths both from space and from the ground, has made the last twenty years one of the truly explosive periods in our scientific history.
Astronomical research from space now needs permanent orbiting observatories. Therefore, this country could take a truly significant step to further space astronomy by establishing such an observatory, or cluster of observatories, furnished with instruments to observe every region of the electromagnetic spectrum. These facilities could be assembled and maintained from Earth orbit. There is thus a close connection between the needs of space astronomy and the scientific opportunities presented by the construction of a Shuttle base or space station. In fact, the carrying out of astronomical observations from space could provide an initial focus for activities aboard the Shuttle base during its construction and development. Beyond the fact that such an enterprise would have tremendous significance for science, it would furnish a clear restatement of the American commitment to the noblest adventures of the intellect.
In summary, we have built a powerful and expensive transportation system to near-Earth orbit; analysis of the economic, technological, and scientific requirements for our future space effort indicates strongly that the next goal of the American space program should be a permanent Earth-orbiting Shuttle base or space station. Such a station should be a service and repair facility for the Shuttle itself, a material and supply depot, a living facility for space workers and a center for research into space habitation, a launch pad for far-space missions, and a facility from which orbiting astronomical observatories can be launched and maintained.
At present, however, the substantial funds needed to exploit the capabilities of the Shuttle and to build upon the STS capital investment are not being made available. Instead, one reads of suggestions that Shuttle development be followed by manned visits to planets or the construction of space colonies, activities which should be postponed until the suitability of prolonged human space habitation has been demonstrated by scientific research and practical experience aboard a near-Earth orbiting space station. Such suggested follow-on programs, which are engineering ventures requiring enormous resources, are in my view some two to three decades away from economical and reasonable pursuit; if implemented too early they can only divert essential funds from the more desirable near-term goal of constructing a Shuttle base or space station. I would therefore strongly hope that NASA's budget over the next decade could be devoted to the exploitation of the Shuttle Space Transportation System for scientific and technological purposes, rather than to longer-term projects that do not directly build upon the Shuttle investment and capability.