Word: orbital
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Dates: during 1990-1999
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...though, most scientists were convinced and began looking for explanations. Several suggested that astronomical cycles were involved, and by the 1930s the Yugoslav astronomer Milutin Milankovitch had constructed a coherent theory. The ice ages, he argued, were triggered by changes in the shape of the earth's slightly oval orbit around the sun and in the planet's axis of rotation. Studies of the chemical composition of ocean-floor sediments, which depend on climate conditions when the material was laid down, more or less supported Milankovitch's predicted schedule of global glaciation...
...rocket booster. Ever since the Challenger blew up less than two minutes after liftoff in January 1986, killing all seven astronauts aboard, the agency has seemed lost in space. Shuttle launches have been delayed by mechanical glitches more often than not. Satellites have mysteriously stopped transmitting while in orbit. Space probes have broken down en route to Jupiter and Mars. Along with the setbacks came a crisis in the spirit of space adventure -- a loss of vision and will to probe the unknown reaches of the solar system and the universe. "How do you follow putting people on the moon...
Thus after last week's triumphant repair mission, relieved NASA officials are now saying, "Thanks, Endeavour, we really needed that." The mission proves that astronauts can handle construction and repair work in orbit -- the skills essential to NASA's pan to build and operate a space station by the end of the decade. Yet space extravaganzas are no longer enough to keep the public and Congress behind the space program. The questions that haunted NASA before the Hubble mission won't go away. Why does the U.S. need a space program anyway? Should the nation be risking lives and spending...
...past the execution would have been a nightmare. "For Mars Observer," says Ghassem Asrar, the program scientist for Mission to Planet Earth, " NASA was involved in every step from start to orbit." Obedient to its bureaucratic, cover-your-backside tradition, the agency demanded that the companies building the Observer, led by General Electric and Martin Marietta, submit endless reams of paperwork documenting every last nut and bolt...
...note that the Hubble could never have been repaired without human hands; opponents argue that without NASA's insistence that the telescope be launched by shuttle, the instrument could have gone up in the late 1970s, at a fraction of its eventual cost and into a higher, more useful orbit to boot...