1.4 The Shuttle Becomes "Operational"
― シャトルの「実用化」―

On the first Space Shuttle mission, STS-1,*11 Columbia carried John W. Young and Robert L. Crippen to orbit on April 12, 1981, and returned them safely two days later to Edwards Air Force Base in California (see Figure 1.4-1). After three years of policy debate and nine years of development, the Shuttle returned U.S. astronauts to space for the first time since the Apollo-Soyuz Test Project flew in July 1975. Postflight inspection showed that Columbia suffered slight dam-age from excess Solid Rocket Booster ignition pressure and lost 16 tiles, with 148 others sustaining some damage. Over the following 15 months, Columbia was launched three more times. At the end of its fourth mission, on July 4, 1982, Columbia landed at Edwards where President Ronald Rea-gan declared to a nation celebrating Independence Day that "beginning with the next flight, the Columbia and her sister ships will be fully operational, ready to provide economical and routine access to space for scientific exploration, commercial ventures, and for tasks related to the national security" [emphasis added].*12

Figure 1.4-1. The April 12, 1981, launch of STS-1, just seconds past 7 a.m., carried astronauts John Young and Robert Crippen into an Earth orbital mission that lasted 54 hours.

There were two reasons for declaring the Space Shuttle "op-erational" so early in its flight program. One was NASAs hope for quick Presidential approval of its next manned space flight program, a space station, which would not move forward while the Shuttle was still considered devel-opmental. The second reason was that the nation was suddenly facing a foreign challenger in launching commercial satellites. The European Space Agency decided in 1973 to develop Ariane, an expendable launch vehicle. Ariane first flew in December 1979 and by 1982 was actively competing with the Space Shuttle for commercial launch contracts. At this point, NASA still hoped that revenue from commercial launches would offset some or all of the Shuttles operating costs. In an effort to attract commercial launch contracts, NASA heavily subsidized commercial launches by offering services for $42 million per launch, when actual costs were more than triple that figure.*13 A 1983 NASA brochure titled We Deliver touted the Shuttle as "the most reliable, flexible, and cost-effective launch system in the world."*14
こんなにも早くスペースシャトルが実用段階に入ったことが宣言されたのには2つ理由があります。1つ目の理由は、NASAが次の有人宇宙飛行計画である宇宙ステーションに移行することへの大統領の賛同を得たいと考えたからです。これらの計画はシャトルが開発段階にあるうちは前に進めることができなかったのです。2つ目の理由は、商業衛星の打上げの分野でアメリカに海外の競合が現れたためです。欧州宇宙機関(European Space Agency:ESA)は、1973年に使い捨て型のロケットであるアリアンを開発することを決定し、1979年の12月には初飛行を行いました。そして、1982年には、実際に商業打上げ契約でスペースシャトルと競合するまでになったのです。この時点でも、NASAは商業打上げによる収入がシャトルの運用コストの一部ないし全てを相殺することができると思っていました。商業打上げの契約を取り付けるために、NASAは一回の打上げの費用を4200万ドルで行うことで商業打上げを支援しました。しかし、実際のコストはこの3倍以上かかっていたのです。1993年にNASAが制作した小冊子『We Deliver』では、シャトルのことをこう表現しています。「世界で最も信頼性、汎用性が高く、経済効率のいい打上げシステム」

Between 1982 and early 1986, the Shuttle demonstrated its capabilities for space operations, retrieving two commu-nications satellites that had suffered upper-stage misfires after launch, repairing another communications satellite on-orbit, and flying science missions with the pressur-ized European-built Spacelab module in its payload bay. The Shuttle took into space not only U.S. astronauts, but also citizens of Germany, Mexico, Canada, Saudi Arabia, France, the Netherlands, two payload specialists from commercial enterprises, and two U.S. legislators, Senator Jake Garn and Representative Bill Nelson. In 1985, when four Orbiters were in operation, the vehicles flew nine mis-sions, the most launched in a single calendar year. By the end of 1985, the Shuttle had launched 24 communications satellites (see Figure 1.4-2) and had a backlog of 44 orders for future commercial launches.

Figure 1.4-2. The crew of STS-5 successfully deployed two commercial communications satellites during the first "operational" mission of the Space Shuttle.

On the surface, the program seemed to be progressing well. But those close to it realized that there were numerous problems. The system was proving difficult to operate, with more maintenance required between flights than had been expect-ed. Rather than needing the 10 working days projected in 1975 to process a returned Orbiter for its next flight, by the end of 1985 an average of 67 days elapsed before the Shuttle was ready for launch.*15

Though assigned an operational role by NASA, during this period the Shuttle was in reality still in its early flight-test stage. As with any other first-generation technology, opera-tors were learning more about its strengths and weaknesses from each flight, and making what changes they could, while still attempting to ramp up to the ambitious flight schedule NASA set forth years earlier. Already, the goal of launching 50 flights a year had given way to a goal of 24 flights per year by 1989. The permission cost was more than $140 million, a figure that when adjusted for inflation was seven times great-er than what NASA projected over a decade earlier.*16 More troubling, the pressure of maintaining the flight schedule cre-ated a management atmosphere that increasingly accepted less-than-specification performance of various components and systems, on the grounds that such deviations had not interfered with the success of previous flights.*17