题目内容
Oases in Space
Earlier space stations
The International Space Station (ISS) is the most complicated international scientific project ever undertaken. First proposed in 1984, it involved the effort of sixteen nations: the United States, Canada, Japan, Russia, eleven nations of the European Space Agency, and Brazil. The first component of the ISS, Zahra ("sunshine" in Russian), was launched into orbit in 1998. A few weeks later, the crew of a U.S. space shuttle brought the second piece, Unity, and connected the two. The launch of the third major component, the Russian Avezda ("star"), was postponed by financial problems until July 2000, and the station's first crew arrived in November. Eventually, the ISS will contain more than 100 parts and will require forty-four spaceflights to deliver them. A total of 160 spacewalks will be needed to assemble the components. The ISS was originally scheduled to be completed in 2006, although unexpected events such as the Columbia space shuttle tragedy of 2003 may delay the date. When work is finished, the station will house a full-time crew of seven astronauts and scientists and contain six scientific laboratories. With an anticipated lifetime of 10 years after completion, the ISS is not only the most complicated scientific project ever undertaken but also, at a projected cost of $ 35 billion, one of the most expensive.
The ISS is not the first space station~ That distinction belongs to the Soviet Union's Salyut 1. Salyut 1 was sent into orbit in 1971 but suffered setbacks. The first crew to arrive was unable to get in: There was something wrong with the hatch(舱口)! The second crew, equipped with special tools, got in and spent 24 days there. However, on the way back to Earth, a tragedy occurred. A valve(气阀)had opened by mistake and let all the air out of the capsule, and the three cosmonauts, who were not wearing space suits, died during the descent. In all, there were six successful Salyut stations. The first -- and only American space station, Skylab, was launched in 1973. To save money, the Americans used the third stage of a Saturn V booster rocket left over from the Apollo moon missions, and so Skylab was much roomier than the Soviet stations. Three crews spent time on Skylab, but the station had to be abandoned in 1975 because there was simply no way to get to it. The United States had used up its Apollo rockets and the first space shuttle wouldn't be launched until 1981. Eventually, Skylab's orbit decayed, and the station fell to Earth in 1979. At the time, some people feared that the debris(碎片)might land in an inhabited area, and a few people even built "Skylab shelters.' However, there was no reason to panic; Skylab burned up harmlessly over Australia. In 1986, the Soviet Union launched another station, Mir ("peace"). Although damaged by an on-board fire and a collision with a supply rocket, Mir stayed in orbit for 15 years, and both U.S. and Russian crewmen, who would later serve on the ISS, trained on Mir.
New designs for space stations
The ISS and earlier space stations are a far cry from the space stations described by science fiction writers and dreamers, and even by scientists earlier in the century. After World War Ⅱ, many German rocket scientists who had worked on weapons programs immigrated to the United States and the Soviet Union. Werner yon Braun, the most famous of these scientists, played a vital role in the early days of the U.S. space program. It was Von Braun who decided that a large space station was essential to the exploration of space, a first step that would provide a stopping place on the way to the moon and the planets. In the March 1952 edition of Collier's Magazine, Von Braun contributed an article about the proposed station and introduced the idea of a wheel-shaped design. Illustrated by the artist Charles Bonestell, this issue popularized the "spinning wheel" or "donut in the sky" d
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Do women tend to devalue(贬低) the worth of their work？ Do they apply different standards to rewarding their own work more critically than they do to rewarding the work of others？ These were the questions asked by Michigan State University psychologists Lawrence Messe and Charlene Callahan-Levy. Past experiments had shown that when women were asked to decide how much to pay themselves and other people for the same job, they paid themselves less. Following up on this finding, Messe and Callahan-Levy designed experiments to test several popular explanations of why women tend to get less in pay situations.
One theory the psychologists tested was that women judge their own work more harshly than that of others. The subjects for the experiment testing this theory were men and women from the Michigan State undergraduate student body. The job the subjects were asked to perform. for pay was an opinion questionnaire(调查表) requiring a number of short essays on campus-related issues. After completing the questionnaire, some subjects were given six dollars in bills and change and were asked to decide payment for themselves. Others were given the same amount and were asked to decide payment for another subject who had also completed the questionnaire.
The psychologists found that, as in earlier experiments, the women paid themselves less than the men paid themselves. They also found that the women paid themselves less than they paid other women and less than the men paid the women. The differences were substantial. The average paid to women by themselves was $ 2.97. The average paid to men by themselves was $ 4.06. The average paid to women by others was $ 4.37. In spite of the differences, the psychologists found that the men and the women in the experiment evaluated their own performances on the questionnaire about equally and better than the expected performances of others.
On the basis of these findings, Messe and Callahan-Levy concluded that women's attachment of a comparatively low monetary value to their work cannot be based entirely on their judgment of their own ability.
The experiment designed in the passage would be most relevant to the formulation(陈述，表述) of a theory concerning the ______.
In Island 3 Lagrange stations people could "fly" through their centers where there was no
Skylab was the only space station that the United States launched by itself.
It was Werner Von Braun who first introduced the idea of building a space Station for exploration.
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