Imágenes de páginas


One of the major contributions of the Space Program to society has been in the field of international communications. In accordance with the Communications Satellite Act of 1962, COMSAT led this nation's first commercial space efforts in the expeditious establishment in 1964 of a commercial, worldwide satellite system, INTELSAT, which now has over one hundred members. The Corporation has served since 1964 as the U.S. Signatory in this commercial space venture and is also serving as INTELSAT's Management Services Contractor. Accompanying the establishment and growth of INTELSAT has been the development and growth of commercial satellites from the 240-circuit "Early Bird" satellite in 1965 to their present capabilities of carrying the majority share of the world's international telephone traffic and all overseas TV programs via earth stations in over 85 countries.

This success has been based in large part on the engineering of commercial communication satellite systems using many techniques and components developed as a result of NASA and DOD programs.

It is recommended that development of advanced technology common to all satellites should continue to be sponsored by the Government and that the design of satellites for commercial uses continue to be funded by non-Governmental organizations.

It is generally agreed that earth resources satellite technology offers great potential benefits to mankind. While it also is generally agreed that the technology to implement an operational system is available, further research and development programs are necessary to increase the potential benefits available from earth resources satellite technology. However, other elements to implement a successful operational system are lacking, namely, a well-developed user community to support an operational system and a clear conception of the roles of government and the private sector in implementing such a system. The private sector has considerable resources, experience and capabilities which could be enlisted in the successful development and implementation of an operational earth resources satellite system. Future space programs should emphasize the exploration of appropriate means by which to best invoke the private sector in an operational role at an early date.


[blocks in formation]

As background to answering the specific questions which you are examining, i.e., the criteria for future space programs, the potential contribution to our society, and needed emphasis in program content, we have prepared an appendix--"Growth and Status of INTELSAT." Its purpose is to demonstrate the evolutionary development of communications satellite technology, following initial Government efforts in this area, and the dramatic growth in the utilization of the commercial, global communications satellite system since its establishment 14 years ago.

Criteria for Future Space Programs

With respect to the criteria to be used for future space programs in the area of communications satellites, we recommend that the detailed design of satellites for commercial use continue to be funded by commercial entities. The availability of the space shuttle may make it more feasible economically for private industry to plan an even greater role in space-related research and development inasmuch as communications experiments and tests will be able to be conducted from the shuttle payload bay. This, in turn, should provide encouragement to industry to develop technology for particular applications in the areas of fixed, broadcast, aeronautical and maritime services.

However, Government-sponsored research and development work should be continued on those areas of advanced spacecraft technology which have broad applications to scientific, military, and applications satellites, including communications. The Government also should continue to sponsor the development of new satellite designs for specific noncommercial purposes, i.e., scientific and military. Government support of new satellite applications having social or government significance, might best be accomplished by a government guarantee of the market rather than by government development of an actual satellite system. An example of a government need satisfied in this manner is the MARISAT system, wherein the government service (for the U.S. Navy) is being supplied by part of a commercial satellite's capability. Private industry undertook the complete risk attendant on developing and launching the satellites, the government is paying only for actual services from a properly operating satellite.

This approach should be followed when the desired needs can be met by a satellite system with existing technology, or by a reasonable extension of such technology. When this approach is not possible, the government, in their other role, should sponsor development of the advanced technology needed.

The Honorable Olin E. Teague -3

January 24, 1978

The extent of private industry participation in such joint projects depends upon the specifics of each case, and these can vary so greatly that one can't generalize. Additionally, NASA could take steps to facilitate efforts by private industry and other non-Governmental entities to test new equipment and demonstrate new services, such as providing flight test opportunities and coordinating "packages" of several industry experiments so as to form experimental shuttle payloads.

Too, Government should continue to take steps to insure the availability of reasonably priced launch services for a wide range of commercial payloads.

Potential Contributions to Society

It is, of course, difficult to provide a quantitative measure of the impact which communications satellite technology will have on the economic and social well-being of the United States and other nations of the world. Nevertheless there has been an impact and this impact will continue.

One way of attempting to measure this impact is to highlight the developments internationally which have taken place since the establishment of INTELSAT in 1964 and the commercial introduction of communications satellite technology in 1965. Such highlights, as are presented in the Appendix, allow us to identify trends which are most likely to continue in the future. They also serve to remind us of the growing global interdependence.

The most obvious trend is the growing membership in INTELSAT, which now totals over 100 nations. Accompanying this has been the growth of the INTELSAT system, not only in terms of antennas interconnecting the world-wide membership, but also in terms of the increasing quantity of traffic carried over the system.

One of the most dramatic trends has been the less developed countries' increasing participation in, and utilization of, the INTELSAT system. Indicative of these trends are the following:

The INTELSAT Board of Governors, which has the responsibility for the design, development, construction, establishment, operation and maintenance of the INTELSAT space segment, is comprised of 26 Governors, 14 of whom now represent, individually or collectively, 54 less developed countries.

The Honorable Olin E. Teague


January 24, 1978

An increasing number of less developed countries are obtaining significantly improved communications at less cost than purchasing their own satellite systems by leasing transponder capacity from INTELSAT for the purpose of meeting their domestic communications requirements. Algeria became the first country to do so in 1975. Since then, 11 other countries either have placed into operation or are planning domestic systems.

Needed Emphasis in Program Content

In reviewing the families of satellites used by INTELSAT during the past decade (i.e., INTELSAT III, IV and IV-A) as well as the INTELSAT V series which is under development and scheduled to enter into operation in 1979, our analysis indicates that the total program cost is divided almost equally between satellites and launch vehicles. Hence, there needs to be continued emphasis in both areas.

Launch vehicles. Development of launch vehicles within the United States, to date, has been undertaken under Government auspicies. We believe there is good reason for this to continue. This means, of course, that the Government will continue to control the cost and capabilities of launch vehicles, and, in so doing, will influence directly the development of satellite technology by non-Governmental and Governmental entities and the opportunities for commercial satellite systems. With the introduction of the space shuttle, we expect that satellites designed specifically for use with the shuttle will benefit from the lower cost per pound to achieve orbit.

In a separate, but related, matter, it should be noted that, until recently, only the United States and the Soviet Union had the capability to launch satellites into geostationary orbit. But in 1977, Japan launched a satellite into such an orbit using a modified version of a Thor/Delta rocket, developed through a licensing arrangement with McDonnell Douglas; the Japanese government also has plans to update this rocket to carry heavier payloads in the future. The European Space Agency (ESA) is actively developing the ARIANE launch vehicle which will be equivalent to the United States Atlas/Centaur. ESA has made offers to INTELSAT for launching the last three INTELSAT V spacecraft with ARIANE, rather than the U. S. space shuttle (the first four spacecraft have been committed to Atlas/Centaur launch vehicles).

The Honorable Olin E. Teague


January 24, 1978

Heretofore the United States has been the sole source for launch vehicles in the western world. But this state of affairs will change dramatically within the decade. Therefore, emphasis is needed on the economic aspect of the space shuttle program if this is to be the primary commercial launcher in a competitive launch vehicle environment. until such time as the space shuttle program has been demonstrated to be technically successful and economically competitive, other launch vehicles, namely the Atlas/Centaur and the Thor/Delta, should continue to be made available.


Spacecraft technology. In areas other than launch vehicles, as indicated in an earlier response, NASA should emphasize work on space technology applicable to all types of spacecraft missions, viz:

• Deployment of large structures in space. This would include work on large antennas including considerations of maintaining surface accuracy and methods of precise pointing, and related studies on large solar arrays for powering spacecraft at the level of kilowatts (and higher) as compared to today's levels of hundreds of watts.

• Improvement in solar cells and power sources.

• Improvements in storage batteries.

· Lightweight structures.

Propagation data for satellite-earth systems from 30 to 300 GHz. Such frequencies have been proposed for various space missions, and factual data is needed to permit evaluation of this frequency range. In order to do this, new microwave components will be needed, and this, too, would seem to be a proper NASA mission.

• Thermal control methods for high power tubes.

Long-term effects of space environment on electronics


Improved attitude control and pointing techniques.
Improved spacecraft positioning methods.

• Lightweight composite materials with low creep.

« AnteriorContinuar »