首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
As every ancient mariner knew, traveling by sail is a simple way to go. Though the winds could be fickle and the boats pokey, th
As every ancient mariner knew, traveling by sail is a simple way to go. Though the winds could be fickle and the boats pokey, th
admin
2011-01-02
93
问题
As every ancient mariner knew, traveling by sail is a simple way to go. Though the winds could be fickle and the boats pokey, the energy source that moved the ship was free, plentiful and renewable. Now the same technology that conquered the oceans of Earth may conquer the ocean of space.
This week a Russian and American consortium will announce plans for an April launch of the first so-called solar-sail vehicle, a multicasted spacecraft that will use sunlight to push itself along. To a public raised on smoke-and-fire rocketry, the idea of drawing energy straight from space seems fanciful. To the people behind the new ship, however, the technology is not only sensible but inevitable, the easiest way to reinvent the business of cosmic travel. "This allows us to use very little fuel to fly very great distances," says Bud Schurmeier, a former NASA engineer and an adviser to the project. "It’s an intriguing concept."
The idea behind solar sailing is simple. Although light is made of massless particles called photons, such ephemeral things exert real pressure, especially when they flow so close a source as the sun. Attach a sail of lightweight Mylar or other material to a spacecraft, set it up in the path of that outrushing energy, and you ought to be able to move in almost any direction.
NASA has a keen interest in solar sailing and had budgeted $ 5 million to investigate 17 possible missions. It may select one as early as next month. But while the space agency has been mulling plans, the people behind the new ship, dubbed Cosmos I, have been getting set to fly. The project is the brainchild of Russia’s Babakin Space Center, near Moscow, and the Planetary Society in Pasadena, Calif., a think tank founded in 1979 by astronomer Carl Sagan and others. The two groups had long been developing plans for a solar-sail mission but got the cash to make it happen only last year when Ann Druyan, Sagan’s widow and head of the Media Company Cosmos Studios, and Joe Firmage, the founder of US Web, threw their names and about $ 4 million behind the effort. "I had talked to people about solar sailing before," says Lou Friedman , former engineer at the Jet Propulsion Laboratory in Pasadena and director of the Planetary Society," but between the Russians’ capabilities and Ann’s vision, I knew this one would click."
The spacecraft is a 3-ft. metal with eight 35-ft. metallic wings. Mylar petals sprout from it -- though the prototype used in the April launch will have just two petals. Mounted atop a reconfigured Russian ICBM and launched from a sub in the Barents Sea, the Cosmos I will fly to an altitude of 260 miles, where it will deploy the wings and float for a minute of so. If all goes well, the wings will then be jettisoned and the sphere aerobraked back to Earth, its bounce-down on Russian soil cushioned by air bags.
By some measures, this cosmic lob shot is not that impressive, but for solar-sail scientists, the engineering is everything. Few doubt that when sunlight strikes the wings, the spacecraft will accelerate; the key is building wings that can open and pivot, allowing the ship to tack into the solar stream. If this mission works, a more ambitious orbital flight, using the eight-paneled craft, is set for the end of the year. The space-craft could circle Earth for months, surfing the sun until de signers shut it down. "There will be a grandeur to it, "says Druyan, "a 70-ft. sail that will be visible to the whole planet."
Grandeur aside, critics wonder if solar sails have a future. The technique is problematic in Earth orbit, since the changing position of sun relative to the space-craft makes constant tacking necessary. Sailing is best used for as the crow-flies shots to neighboring planets. Even in these cases, progress can be slow, since sunlight exerts, at most, 2 lbs. of pressure per square haft-mile, requiring a year or more to rev a spacecraft to interplanetary speeds. Worse, beyond Jupiter, sunlight flickers out almost entirely; to go any farther would require energy beamen from Earth orbit, perhaps by giant laser howitzers. "None of these things has been tested, "says Mel Monte-merlo, one of NASA’s solar-sailing chiefs. "We have a long way to go."
Whether that will continue to seem such a long way may depend on the spring-time flight of Cosmos I. A successful mission has a way of making impossible technologies seem possible -- a big burden for a small rocket that will, for one day at least, carry the hopes of the world’s space community.
What can be inferred from the passage?
选项
A、Most scientists are confident that the spacecraft will work well.
B、A more ambitious orbital flight will follow this mission.
C、The author is quite sure that this mission will make impossible technologies seem possible.
D、The key of the engineering of Cosmos I is building wings that can open and pivot.
答案
D
解析
该题问:从本文中可以得出什么结论?A项意为“大部分科学家都相信宇宙飞船会运行得很好”,从本文的倒数第二段可以看出此项不正确。B项意为“一个更为有抱负的轨道飞行器将会从事这个特别任务”,本文没有提及。C项意为“作者相信这个任务会使得不可能的目标显得有些希望”,本文中提到的是A successful mission has a way of making impossible technologies seem possible,因此C项中mission前必须加上successful,此项才正确,因此C项不可取。D项意为“宇宙1号操作的关键是能否造出在太空中可以打开的翅膀,而且这些翅膀还能够旋转”。这在第六段中可以找到出处the key is building wings that can open and pivot。因此D项为正确选项。
转载请注明原文地址:https://www.kaotiyun.com/show/L1eO777K
0
专业英语八级
相关试题推荐
Therehavebeenagreatmanyexplanations,someofthemverycomplicated,ofthegreatdemandforcollegeeducationinAmerica,
RestrictingtheproblemofThirdWorldcountriestohungeralone—althoughnotallpeoplewholiveinpovertyarepermanentlysta
InformationSuperhighwayatWorkThechangesinhowwecommunicatemakeitnecessarytochangehowwethinkaboutcommunicati
OncefoundalmostentirelyinthewesternUnitedStatesandinAsia,dinosaurfossilsarenowbeingdiscoveredonallsevencont
A、ThelOCB、ThelOCexecutivecommittee.C、TheIOC’stechnicalevaluationteam.D、TheIOCcommittee.CA奥运会;B奥运会执委会;C奥运会技术评估小组;D
Federaleffortstoaidminoritybusinessesbeganinthe1960’swhentheSmallBusinessAdministration(SBA)beganmakingfederal
CharacteristicsofaBureaucracyPeopleusuallyholdnegativeopiniontowardsbureaucracy,butaccordingtoMaxWeber,burea
ElizabethwasfortunatetobeborninthelullflushofRenaissanceenthusiasmforeducation.Womenhadalwaysbeeneducatedof
A语言学概念的实例分析。该题属于句法学的范畴。单词在句中的位置不可随意调换,这是由句法学结构主义学派提出的.Syntagmaticrelation(组合关系)规定的。
B英国文学之作家作品。GeorgeBernardShaw(肖伯纳)是英国现代著名的戏剧家,其代表作为Pygmalion(《皮革玛丽翁》,又名《卖花女》)。
随机试题
下列对交易成本的表述正确的有()。
下述哪条不属强迫症状()
A、药物从给药部位进入体循环B、药物在机体内发生化学结构的变化C、药物在机体内发生化学结构的变化及由体内排出体外D、药物从血液向组织器官转运E、原型药物或其代谢物由体内排出体外药物消除是指
医疗机构配制制剂的最重要条件是
成釉细胞瘤的临床特征错误的是()
卖券还款是指客户通过其信用证券账户申报买券,结算时买入证券直接划转至证券公司融券专用证券账户的一种还券方式。( )
甲公司决定2007年12月31日开始对存货采用成本与可变现净值孰低法计价。2007年12月31日与2008年12月31日的有关存货的数据如下:成本
股份有限公司为了使已发行的可转换债券尽快地实现转换,或者为了达到反兼并、反收购的目的,应采用的策略是()。
赵某、钱某都是某公司的职员,两人同住一宿舍。2007年春,公司派赵某到珠海办事处工作1年。临行前,赵某将已使用了1年的一台电脑委托给钱某保管并允许其使用。1个月后,赵某给钱某写信说自己买了一台笔记本电脑,委托其保管的电脑可以适当价格出售,但modem因还有
TodayI’dliketotalkaboutwhathelpspeoplesuccessfullyintegrateintoanewculture.Whereasthereasonsformigrationare
最新回复
(
0
)