SUMMARY

In 1972 solid progress was made in the Space Shuttle program. With the final Space Shuttle system configuration selected on the basis of firm technical and economic considerations, the President proposed and Congress approved the development of a low-cost space transportation system using the Space Shuttle concept. A contractor was selected for development of the Orbiter vehicle and for systems integration and the contract for development of the Orbiter main engine was finalized. Systems requirements were defined and a firm program baseline was established, Shuttle harware development and testing were initiated, and launch and landing sites were selected. The Shuttle program organization was established and a management plan selected which would keep management costs to a minimum by taking full advantage of available capabilities and resources. Major program milestones were defined, master schedules prepared and procedures developed to assure that program objectives are achieved on schedule and within authorized funding limits. Plans for the next fiscal year call for a buildup in prime and subcontractor manpower for the Orbiter and Space Shuttle main engine development and the award of contracts for all major elements of the Shuttle, including the external tank and the solid rocket booster. Fiscal year 1974 funds will provide for an expanded scope of design, development, and testing activities and for continuation of subsystems and component development. With the hardware development phase of the Space Shuttle program well underway, program schedules and funding projections are based on momentum gained during the past year.

Today's biggest challenge is to reduce the cost of operating in space. We are confident of increased benefits, new discoveries, and new applications. These prospects will be realized by the Space Shuttle.

The operational Space Shuttle of the 1980's will bring into existence a new economical era in space operations. It will allow us to continue the profitable exploitation of Earth resources, improvement of worldwide communications and education, development of international understanding, and enhancement of national security, and make it possible to take advantage of many new opportunities in space.

MISSION AND PAYLOAD INTEGRATION

INTRODUCTION

The Space Shuttle, Sortie Lab and Tug (figure 164) (see p. 438) will make possible a new and more productive period of space activities. However, effective utilization of the capabilities and unique characteristics of this space transporation system will require an approach to the development of space systems and space operations different from the systems in use today. The Space Shuttle will carry into space virtually all of the Nation's civilian and military payloads, manned and unmanned. It will launch and return communications, weather, Earth resources and navigation satellites. It will place instruments into Earth orbit and deep space for scientific investigations. Launch services for the Department of Defense and other agencies of the U.S. Government, foreign countries, private industry, universities and research organizations will be provided. Flight opportunities will be frequent and response time short. Payloads will be repaired on orbit or retrieved and returned to the ground for refurbishment and reuse figure 165) (see p. 438).

The Space Shuttle will have the capability of carrying passengers into space. The present stringent physical standards for space flight will be relaxed. Passengers may include scientists, engineers, technicians, journalists, television crews or others whose business takes them into space (figure 166) (see p. 439).

In view of these new capabilities of future space missions, special attention must be devoted to devising approaches and procedures to take advantage of the Shuttle system and to insure their compatibility with the goals and objectives of prospective users. At the same time, the compatibility of the interfaces between each payload and the carrier vehicle must be assured. To accomplish this program requires the development of innovative ideas, concepts, system requirements and management procedures to ensure efficient and economical utilization of the Space Shuttle, Sortie Lab and Space Tug capabilities by the various payload designers and sponsors. The importance of these activities has been recognized within NASA, and a Mission and Payload Integration Office has been formed within Manned Space Flight to be the focal point for Space Transportation System payload related activities.

FIGURE 164

FIGURE 165

The Mission and Payload Integration Office is responsible for the planning, direction and coordination of payload activities between the various elements of the Space Transportation System (Space Shuttle, Sortie Lab and Space Tug) within the Office of Manned Space Flight and the payload sponsors (the Office of Space Science, the Office of Applications, the Office of Aeronautics and Space Technology, the Department of Defense, and other Government agencies, both foreign and domestic). These activities are described as follows:

PAYLOAD ANALYSIS AND REQUIREMENTS

Payload Analysis and Requirements activities are directed toward the formulation of payload characteristics and requirements which establish the design and operational parameters of the Space Transportation System. Additional studies are directed toward derivation of payload concepts and low cost design approaches to fully utilize the characteristics of the various elements of the Space Transportation System. The payloads are analyzed by the cognizant personnel in the discipline offices (Astronomy, Space Physics, Life Sciences, etc.) and defined in terms of the physical characteristics of the payload at the subsystem level. The mission orbit elements, identification of the type and volume of data to be gathered from the payload operating in space and statements concerning the preferred operating mode of the payload are also prepared. Based on these payload characteristics, engineering cost organizations at the NASA Field Centers determine the cost elements for each prospective payload in terms of development, investment and operating costs. Working with the payload sponsors, the Mission and Payload Integration Office will fund and manage studies as neecssary to support these payload analysis and requirements activities. Both technical and cost analysis will be performed, utilizing payload factors (figure 167) (see p. 440) described as follows:

92-228 (Pt. D) O-73-29

• SPACE ENVIRONMENT FLIGHT TEST (7 DAY SORTIE MODE)

1. Increased Weight and Volume in the Space Shuttle cargo bay provides flexibility for the payload designer. The relaxation of constraints on weight and volumetric geometry allows the designer to package his components with lower density and easier access for repair. Less restrictive weight limitations will permit the use of increased design margins which will permit reduced testing, redesign and rework. This in turn should reduce the cost of manufacturing, engineering, test, and analysis.

2. Space Environment Flight Test on sortie flights has been viewed as a bene ficial mode for Space Shuttle operations for advancing the state-of-the-art of components and subsystems and demonstrating prototype spacecraft (figure 168). Shortened development time and decreased spacecraft operational risk can be realized from testing on Shuttle sortie missions prior to commitment to operational practice.

3. Payload Retrieval by the Space Shuttle has been recognized as one of the more significant elements leading to low cost payload programs. Although a failed payload returned to Earth for analysis appears enticing from the cost and technical design viewpoint, the potentail cost savings from refurbishment and reuse is the major consideration for retrieval (figure 169). Our payload studies to date show that payloads, if properly designed, can be refurbished for the average of approximately 25 percent of unit cost. Further, the studies show that refurbishment, coupled with reuse, can reduce total payload program costs by 30 to 40 percent.

4. On-Orbit Checkout and Maintenance of the payload while it is still under the cognizance of the Space Shuttle can significantly reduce the effect of early spacecraft malfunctions. Examination of past spacecraft malfunctions has shown that nearly half of all spacecraft anomalies have occurred during the first week after liftoff. In some cases the crew will be able to take corrective action when problems arise during this period. If on-orbit corrective action is not possible. the spacecraft can be reloaded on the Shuttle and returned to the landing site for repair.