一周精选（周三补作业）又来啦~~~~~~，本周来一个很不擅长的科技主题，高大上的拯救卫星。尽管我小时候一度立志做一个天文学家，但后来连初中数学都没法好好领悟的我，还是很自觉的放弃了这个念头。之所以选择这篇文章，一是保证一周精选体裁的广泛性，二是该文章中一些对卫星工作，周边环境的描述很抽象，非常类似于GMAT喜欢的文章。（可参考OG13 阅读第4篇）
一周精选经过前几期的发展，本期开始决定做一个小小的变动，那就是将思路梳理和难词难句结合，这样方便大家阅读。
还有一个好消息就是，我们的“三好学生”越来越多啦（鼓掌~~~）
依旧保留一周精选的帖子内容和回帖
精华文章回顾帖的选文标准，内容及回帖标准如下：
选文：文章本身有一定的难度，适合精读；内容优秀，具有启发性
数量：1-2篇不等，视当周帖子内容而定
帖子内容：Part I：原文回顾；Part II：全文思路梳理，难词解读，长难句分析
如何回复本帖： 重新再练一遍，计时 or 回忆，然后回复本贴，查看隐藏内容 Part II 并从本贴的最下面选项中选择一个（就是那个ABCD） 最后，只要你有关于过去一周内文章的问题，都可以贴出来大家讨论。当然，也十分欢迎大家对LZ水平各种吐槽（写这句话的时候内心不断告诉自己敢直面批评才是真的勇士 ）
一周精华文章回顾帖的初衷是希望带有娱乐精神的来跟大家一起回顾我们过去一周的成果，所以不要太拘泥，不要太严肃，小分队是严肃的，但在这里，我们一起学英语，练阅读，一起吐槽一起High
最后还有一件事忘了告诉大家，那就是每周的精华回顾贴不记录考勤，撒花~~~~
本期的选文来自ZXPPX的37-11系列越障
Part I: 原文回顾
How to revive a satellite
[Paraphrase 1]
"WE JUST made contact. I need to talk to you in 30 minutes," says Keith Cowing, the editor of NASA Watch, an online publication. Just as Babbage called him, Mr Cowing received word from the Arecibo Observatory in Puerto Rico that his colleagues had made contact with a NASA satellite launched in August 1978. When your correspondent called back, Mr Cowing was irrepressible: the satellite had responded to commands and was now set into "coherent ranging mode", which should make it easier to talk to it. The group had captured the satellite.
This was no act of space piracy. Mr. Cowing, Dennis Wingo of Skycorp and several other experts had received permission from NASA to take control of a satellite for which the space agency has no further purpose nor funding. With the help of nearly $160,000, raised through crowd funding, the team hopes to start a new mission and release the raw data that emerge.
The International Solar-Environment Explorer (ISEE-3, see picture) completed its initial mission close to the sun, where it took measurements of solar properties, and was repurposed in 1983 to hunt comets as the International Commentary Explorer (ICE). During its second lease on life it intercepted comet Giacobini-Zinner in 1985 and then transited between the sun and Halley in 1986. This repurposing involved a series of intricate flybys of the Earth and the moon to slingshot the satellite into its comet-tracking trajectory. NASA shut down the mission in 1997, although occasionally checked in on the bird's status.
Before they turned off the light, Robert Farquhar, the mission's flight-dynamics manager, and his team used the satellite's propulsion system to set it on a course that 28 years after its final scientific measurements in 1986 would bring it close to Earth. The rendezvous is rapidly approaching. Dr Farquhar is now part of the ISEE-3 Reboot Project to re-establish contact. Mr Cowing says participants range in age from their 20s to their 80s, and include ex-NASA employees like himself as well as a current one who works on the project in his spare time.
Although the ISEE-3 was launched a year later than the Voyager 1 and 2 probes, its computers are much less powerful. The Voyagers had redundant sets of three separate computers and could store and execute programs, as well as radiological power sources. ISEE-3 can be triggered through radio commands to execute sequences of actions, but it cannot be put into an autonomous mode. Its batteries failed 20 years ago, and it is now entirely dependent on solar power.
It appears to have survived unscathed the long occupancy of the orbit in which it was parked. However, celestial mechanics have put the satellite about 250,000km off from where it was expected. Mr Cowing and his colleagues are slightly worried that it may bash into the moon or wander too close to Earth. The craft has antennas measuring 30 meters and extending in four directions, which at a certain altitude above Earth could cause problems. "It's a 360-foot spinning cookie cutter," says Mr Cowing.
That the reboot project has got that far is remarkable. Unable to receive a clear go-ahead or an outright no from NASA a few months ago, it set out to raise funds hoping that this might prompt the space agency to acquiesce. It is the first time in NASA's history that operational control has been handed over, and NASA made the announcement on May 23rd with due fanfare.
With the original software, computers or telecoms gear long gone, the team—with the help of some original mission members and others in and out of NASA who knew where to find the old manuals—recreated the equipment, including a software-defined radio system that allows talking and listening to the satellite. The Arecibo Observatory also provided help: it installed gear purchased by the Reboot Project and allowed it to use Arecibo's huge satellite dish free during downtimes. The team faced downpours of rain and even an earthquake with a magnitude of 5.8 while one of the volunteers worked near the dish.
Much remains to be determined. Mr Cowing and his colleagues have yet to decide whether the satellite is to explore more comets or to use it for other purposes. Just as both Voyager probes remain active and Voyager 1's ancient instruments in 2013 produced measurements that upended some long-held notions about interstellar magnetic fields, the group expects that its craft can provide data worth examining. The team will soon give up its big "ear" at Arecibo and decamp to Morehead State University in Kentucky: the initial capture and the repositioning allow the use of the smaller dish there.
This initial contact indicates that the satellite's computer and radios are functioning. The next steps are to determine more fully whether its control systems work as expected and test its instrumentation and propulsion. The team must fire its rockets by mid-June to reposition ISEE-3. The next big challenge will come when the satellite swings around the moon onto its shadowed side and is cut off from the sun. The craft will power down for the first time in many years, and the team hopes when it sees it again, it will wake up and resume communications. It has lasted this long, and the group hopes for many more years to come. "This thing has had a second act, and we're giving it its third," says Mr Cowing.
[900 words]
Reply Your Answer to Check analysis
（原帖链接请戳这里 http://forum.chasedream.com/forum.php?mod=viewthread&tid=907829&fromuid=703710)
Part II: 思路梳理，难词难句
我相信这种情景式的开头瞬间会把很多同学的思绪带走，因为全篇文章忽然就从描述一个场景开始，而且这段描述还不是那么好理解。在收到来自波多黎各A天文台的同事发来的信息后，Cowing难以抑制激动的心情：“终于联上啦！”联上啥了？一颗NASA1978年发射的卫星（好吧，比我还老）。于是乎，本篇文章的故事就这么开始了，中心词就是“拯救老卫星”
这段解释一个词汇，irrepressible, 1, (of a person) lively, happy and full of energy; 2 (of feelings) vert strong, impossible to control or stop。这个词就可以充分的把全文的感情烘托出：鸡冻！
2-4这三段描述了整个故事的背景，并告诉读者这不是在搞太空间谍（space piracy），而是一种新兴的业务，“回收”旧卫星。（请原谅我此时脑海中浮现出了脚踏三轮车，回收旧家电的老大爷形象）。Cowing团队获得了NASA的官方授权（permission），控制一颗叫做ISEE3的退役卫星，以便重新产生价值。ISEE3过去是一颗测量太阳的卫星，1983年又被派去追踪彗星。这里有一段描述可能大家无法理解，啥叫intercepted comet G-Z and transited … Halley? 这句短短的话其实是描述了ICE的赫赫战功，查了一下资料，ICE于1985年9月11日穿越了comet Giacobini-Zinner （贾可比尼秦诺彗星）的离子尾，又于1986年与哈雷彗星相遇。
第四段有一个长难句，Before they turned off the light, Robert Farquhar, the mission's flight-dynamics manager, and his team / used the satellite's propulsion system / to set it on a course that / 28 years after its final scientific measurements in 1986 / would bring it close to Earth. 在关闭ICE之前，Robert和他的团队利用ICE的推进系统设定了一个28年后自动靠近地球的程序。（好高大上啊，有点科幻的感觉）我估计这也是为什么ICE会被选中为重新利用的卫星的重要条件之一。
5-6段则描述了任务是有多么的困难。ISEE3（也就是ICE啦）的电脑不给力，只能通过无线电命令执行操作。也没有自动模式，电池也fail了。另外它被放在了离预想地点250000km远的地方。（可以绕地球6圈多啊）Cowing团队也担心它会离月球或者地球太近。除了这些客观因素，来自NASA的人为因素也带来了困难，例如NASA的态度不明确。当然，Cowing通过筹集资金获得了NASA的勉强同意（acquiesce: to accept sth without arguing, even if you do not really agree with it)，这是一个多么聪明的办法啊！
第7段则描述了如何“回收”ISEE3，立志做一个天文学家或者生活大爆炸中的Howard的同学可以仔细研究这一段，比如什么是software-defined radio system 和 satellite dish。
最后两段自然就是强调任重而道远啦。很多的事情都还没有被决定，到底是探索更多的彗星呢，还是干点其他的。不过尽管联系上了，但ISEE3的控制系统，仪表和推进系统是否完好也都是未知数。要定位ISEE3还得发射火箭。更大的挑战是当ISEE3躲到月球阴面，失去太阳能后，还是否可以再联系上。不过美好的愿望总归还是要有的，它已经重生过一次，我们希望再让它重生一次（This thing has had a second act, and we're giving it its third）
本期的一周精选文章回顾就到这里了，如果有什么疑问或者指正，欢迎回帖提出。 |
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发表于 2014-6-11 23:46:21
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