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The Space Transportation System is the keystone of our future role in space. It marks the beginnings of routine operations and a period of rapid growth of services and benefits in many directions. It promises an era of greater international cooperation as experience demonstrates the advantages of the system. It is the avenue to accelerated commercialization of space, if future development efforts are planned along lines that invite the investment of private capital.
During early flights, the Shuttle/Orbiter will serve two roles. For some missions it will provide transportation to low earth orbit, from whence payloads will be deployed to their orbits of operation. For other missions, such as Spacelab, it will provide an operations base where experiments can be performed under the control of crew members for as long as the Orbiter is able to provide the necessary services and support. It is in this mode that we see the opportunity to expand space services to provide more benefits to mankind. Development of standard payloads, as well as having people on orbit for monitor and repair and prolonged orbital stay-times, will significantly extend our capabilities in space and allow us to implement a greater span of beneficial services.
The public must be convinced of the benefits, and they must also be convinced that our plans will ensure that their money is being spent wisely and efficiently. The key to expanding our capabilities in space and responding to the need for economic justification is to extend the routine services that a Shuttle/Orbiter will be able to provide for only a limited period of time at low power levels. Ideas for auxiliary systems to produce additional services and utilities have been introduced. With access to such services, payloads can be more efficient and can operate for prolonged periods.
Conceptually, an auxiliary system which we call a service center would replace the Orbiter as a berthing station for payloads (including Spacelab). This center would provide electrical power and heat rejection, stationkeeping and positioning, and communications. Relieved of providing these requirements independently, payloads become simpler and less expensive. Even more significantly, the cost for repetitive launching, orbiting, and return of payloads is eliminated.
Development of a service center may be the single most important and fruitful development to follow the Space Transportation System. We are aware that other countries, particularly Germany, have realized its significance and are interested in its pursuit. Its importance to this country must be emphasized, for it is a key development for much of our future space activities.
Preliminary studies show that this capability can be initiated for a low initial cost. We see a period of rational growth during which the program is simple at the beginning, grows in accord with demand, and provides orbital services under a plan that has the flexibility to meet the changing and growing needs of all space users. This approach will ensure retention of U.S. leadership in space in a framework that recognizes the necessity of adhering to a limited budget.
The attached figure, which shows a typical plan under consideration by NASA, illustrates how an evolutionary approach to a service center can be implemented. At upper left (a) is shown the simplest approach to extending Shuttle/Orbiter capabilities: providing extra power for experiments and extending orbital stay-time. This can be done with deployable solar power arrays and radiators packaged in the Orbiter cargo bay. The next extension of capability (b) is a simple, free-flying power module a "plug in" utilities center for the Orbiter for missions that require additional power and orbital stay-time. The underlying idea for the simple service center is to configure it initially for easy, logical growth along lines that closely match growing needs.
In the next phase (c), payloads can be parked in orbit while attached to the service center. This step eliminates the need for repetitive transport of payloads like Spacelab into orbit and marks the beginning of automated on-orbit operations. Manned attendance is still limited to using the Orbiter. In step (d), the service center has been augmented to provide more power and added services. Multiple payloads are berthed to it. They operate in an automated mode with periodic tending by the Orbiter for servicing, replenishment of consumables, repair, and maintenance. Data and command links are in full operation.
The service center could be expanded as shown in (e) and (f) to provide full basic utilities, plus an operations module (perhaps a modified Spacelab) to house servicing personnel. Other special-purpose modules may be required as the program progresses. These would be interconnected, serving as a centralized permanent facility in space. Eventually, with the use of orbital transfer vehicles, remote services to independent satellites can be provided. We can now fully utilize the advantages of environments not found on the earth's surface for producing a range of useful products. An orbital service center can provide industry with an early capability for proceeding with developments and demonstrations leading to industrialization of space. When this stage is reached, the Space Transportation System reverts entirely to its intended transportation role: that of a reusable transportation system. The service center fulfills a need that might otherwise call for a larger Orbiter fleet.
The importance of an orbital service center is underscored by the results of an international and domestic survey we recently initiated to determine the views of a broad spectrum of potential users regarding such a development. The results are not complete, but they show universal agreement regarding the need for orbital services such as power, replenishment of consumables, communications, and manned attendance. Some observers note that providing these orbital services is the only solution for complex experiments that will require more time to accomplish than the Shuttle/Orbiter alone can provide.
It is important to observe that the above system will be developed and deployed in an evolutionary and prudent manner, compatible with other national needs and priorities.
In answer to your letter of 19 December 1977, I appreciate the opportunity to participate in your review of the U.S. space program by presenting COMSAT's views on two areas in which the Corporation is most directly involved--communications satellites and earth resources satellites. Enclosed is an abstract, as per your request, of our comments on this important subject, see Section I.
Communications, as discussed in Section II of our response, is the first area in which space technology was applied commercially. In accordance with the Communications Satellite Act of 1962, COMSAT led this nation's first commercial space efforts in the expeditious establishment of a commercial, worldwide satellite system, INTELSAT, and has served since then as the U. S. Signatory in this commercial space venture.
Earth resources satellites, as discussed in Section III, represents the next possible area in which satellite technology may be applied commercially. COMSAT General, our wholly owned subsidiary, has been evaluating the potential commercial application of such technology, in addition to participating in the U.S. domestic COMSTAR and SBS satellite systems, the MARISAT system, and the AEROSAT program.
Joseph V. Charyk
950 L'ENFANT PLAZA, SW WASHINGTON, DC 20024 TELEPHONE 202-554-6030
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