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
2010-02-20
35
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-tire 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 in triguing 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 B arents 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 every thing. 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 designers shut it down. "There will be a grandeur to it," says Druyan, "a 70-ft. sail that will be visible to the whole plan et."
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 pres sure per square half-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 does "brainchild" in the paragrapth 4 mean?
选项
A、Patent.
B、Invention.
C、Hope.
D、Pride.
答案
B
解析
该题问:第四段中brainchild是什么意思?A项意为“专利”,文中没有提及。B项意为“发明”,从文中第四段The project is the brainchild of Russia’s Babakin Space Center,near...来看,B项为正确选项。C项意为“希望”,D项意为“骄傲”,都不符合题意。
转载请注明原文地址:https://kaotiyun.com/show/revO777K
0
专业英语八级
相关试题推荐
Codeswitchingiswhenpeopleswitch,orchange,fromonelanguagetoanotherwhilespeaking.Theymightbeginaconversationin
Theteachingsequenceisintendedtohelplearners(1)inwritingshortanswers.Itconsistsofthreestages:(2),thepractice
ThediscoveryoftheAntarcticnotonlyprovedoneofthemostinterestingofallgeographicaladventures,butcreatedwhatmigh
Thecaseforcollegehasbeenacceptedwithoutquestionformorethanageneration.Allhighschoolgraduatesoughttogo,says
Onceitwaspossibletodefinemaleandfemaleroleseasilybythedivisionoflabor.Menworkedoutsidethehomeandearnedthe
Onceitwaspossibletodefinemaleandfemaleroleseasilybythedivisionoflabor.Menworkedoutsidethehomeandearnedthe
A、Itisafriendlyfaceoracleverjoke.B、Itisafacialexpressioninvolving43muscles.C、Itisanexerciseoffacialmuscle
A、Anycoloroftherainbow.B、Acolormadebymixingthreecolorstogether.C、Acolorthatcannotbemadebymixingotherstoget
In1896aGeorgiancouplesuingfordamagesintheaccidentaldeathoftheirtwo-year-oldwastoldthatsincethechildhadmade
In1896aGeorgiancouplesuingfordamagesintheaccidentaldeathoftheirtwo-year-oldwastoldthatsincethechildhadmade
随机试题
简述张贤亮小说创作的思想和艺术特色。
A.固定胸壁B.开胸探查C.迅速封闭胸壁伤口D.抗感染E.穿刺排气减压多根多处肋骨骨折的紧急处理应
A、十二指肠球部穿透性溃疡B、胆道结石并感染C、急性肠梗阻D、急性轻型胰腺炎E、急性重症胰腺炎女性,60岁,进食涮羊肉4小时后出现右上腹痛,向右肩放射,体温38℃,巩膜黄染,右、中上腹部压痛、反跳痛。超声:胆囊增大,腔
下列关于股利政策的表述中,正确的有()。
甲将其位于某住宅楼顶层的一套住房出租给乙,租期2年,月租金9000元,但未约定租金支付方式,书面租赁合同签订当日,乙向甲支付了1年的租金。租期第2个月,房屋天花板严重漏雨。乙通知甲维修,甲以合同未约定维修条款为由拒绝。乙只好自己找人维修,花去维修费800
根据贸易技术壁垒(TBT)协议的规定,各成员国的()与国际标准不一致、对贸易有影响时,必须向WTO通报。[2006年真题]
阅读下列材料,并回答问题。最近,班主任李老师发现,班上的张同学傍晚放学后经常留下来帮助当天值日的同学一起打扫卫生。李老师想到班级一直缺乏一种助人为乐的良好风气,她认定张同学具有助人为乐的品德,决定树立典型,于是设计了一个主题班会活动,并让张同学做
理性经济人假设是西方经济学理论的逻辑基础,这一理论假设的核心是认为人()。
当前服务型政府的方向主要包括()。
网卡的物理地址一般写入()中。
最新回复
(
0
)