2007年VOA标准英语-Three Years Later Mars Rovers Keep Going

By David McAlary
Washington
04 January 2007

Two U.S. robotic rovers are entering their fourth year exploring opposite sides of Mars, an unexpected length of time for a mission planned for only three months. Yet, now after three years, the mechanical geologists¹ keep plodding² along, studying Martian rocks and soil. Although they show certain signs of aging, VOA's David McAlary reports that new computer software has given them expanded capabilities³, proving you can teach an old robot new tricks.

 
Mars Rover 
It was January 3, 2004 when the exploration rover Spirit plunged⁴ through Mars' atmosphere in a protective balloon-like cocoon⁵ and bounced to a stop inside a crater⁶.

As an expectant team of scientists and engineers waited tensely at the Jet Propulsion Laboratory in California, mission controllers followed its trajectory⁷.

Mission controller: "A signal indicates we are bouncing on the surface of Mars. This is a very good sign."

Three weeks later, the rover Opportunity did the same on the other side of Mars.

The U.S. space agency NASA had thought that the planet's extremely frigid⁸ temperatures and dust storms would keep their lives short. But rover project scientist Albert Haldemann notes that they have far exceeded their planned lifetime.

"We expected some extended mission lifetime," he said. "We designed the warranty⁹ for these rovers for three months on Mars and we tested for nine months. So one might expect that we would have gotten nine months for free, and here we are at three years."

The twin rovers' major findings came within the first 90 days. Opportunity found chemical evidence in bedrock that a shallow salt water sea existed at some time in Mars' past. Spirit drilled into volcanic¹⁰ rocks and found minerals suggesting they had been carried by water and collected in the lava's tiny pores as it hardened.

The editor of the Internet website Marstoday.com, Keith Cowing, says those discoveries alone justified¹¹ the mission.

"If they had both done that, or even if one of them had landed and still done that, it would have been considered a resounding¹² success," said Keith Cowing. "But these amazing little robots are still going."

 
Mars
Albert Haldemann says the inspection¹³ of the bedrock has been key to understanding Mars' evolution. He notes that the layers in bedrock are a geological history book.

"When you find rock that is attached to the planet, that then tells you about the history of that place," he said. "We have done that now in detail in two places on Mars. That tells us that Mars is a diverse place, that there are significant differences on these two sides of the planet where the rovers are, that Mars has complex geology, not unlike Earth in that sense."

Since their early days, Spirit and Opportunity have roamed seven and 10 kilometers respectively past their original landing sites. Spirit is currently inspecting rocks and soils near a ridge¹⁴ while its twin is exploring a crater with exposed rock layers that tell a longer span of Martian history than those it examined before.

Haldemann attributes their longevity¹⁵ to careful ground control and good luck with Martian weather.

"Mars has been kind to these two rovers," he noted¹⁶. "Both have had gusts¹⁷ of wind blow dust off of solar panels at different times during the mission, and each time that has happened, it has cleaned the solar panels and basically reset¹⁸ us as far as energy levels go, back to the beginning mission. That has been a new lease on life a couple of times for each rover."

The rovers are going about their work reinvigorated with new navigation software uploaded into their computers. One of the technicians who guides the rovers, Scott Maxwell, says the improvements have made them smarter and more independent.

"They are now better than they used to be at finding their way through fields of obstacles," he said. "They can keep an eye on something as they are driving and make sure that they get close to that particular thing because it is an interesting science target. They have figured out how to watch the skies for clouds or watch the terrain¹⁹ for dust devils blowing by, and when they find those and they know those are interesting to us, to send back data on those. They have gotten smarter just as we have gotten smarter."

The rovers have some mechanical wear and tear, but nothing serious enough to stop them. Albert Haldemann says they have just survived another Martian winter and believes that if dust storms do not block the sun's energy and cause the batteries to die, they could last another 18 months until the next Martian winter.

1 geologists   

地质学家，地质学者( geologist的名词复数 )

参考例句：

• Geologists uncovered the hidden riches. 地质学家发现了地下的宝藏。
• Geologists study the structure of the rocks. 地质学家研究岩石结构。

2 plodding   

a.proceeding in a slow or dull way

参考例句：

• They're still plodding along with their investigation. 他们仍然在不厌其烦地进行调查。
• He is plodding on with negotiations. 他正缓慢艰难地进行着谈判。

3 capabilities   

n.能力( capability的名词复数 )；可能；容量；[复数]潜在能力

参考例句：

• He was somewhat pompous and had a high opinion of his own capabilities. 他有点自大，自视甚高。 来自辞典例句
• Some programmers use tabs to break complex product capabilities into smaller chunks. 一些程序员认为，标签可以将复杂的功能分为每个窗格一组简单的功能。 来自About Face 3交互设计精髓

4 plunged   

v.颠簸( plunge的过去式和过去分词 )；暴跌；骤降；突降

参考例句：

• The train derailed and plunged into the river. 火车脱轨栽进了河里。
• She lost her balance and plunged 100 feet to her death. 她没有站稳，从100英尺的高处跌下摔死了。

5 cocoon   

n.茧

参考例句：

• A cocoon is a kind of silk covering made by an insect.蚕茧是由昆虫制造的一种由丝组成的外包层。
• The beautiful butterfly emerged from the cocoon.美丽的蝴蝶自茧中出现。

6 crater   

n.火山口，弹坑

参考例句：

• With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
• They came to the lip of a dead crater.他们来到了一个死火山口。

7 trajectory   

n.弹道，轨道

参考例句：

• It is not difficult to sketch the subsequent trajectory.很容易描绘出它们最终的轨迹。
• The path followed by a projectile is called its trajectory.抛物体所循的路径称为它的轨道。

8 frigid   

adj.寒冷的，凛冽的；冷淡的；拘禁的

参考例句：

• The water was too frigid to allow him to remain submerged for long.水冰冷彻骨，他在下面呆不了太长时间。
• She returned his smile with a frigid glance.对他的微笑她报以冷冷的一瞥。

9 warranty   

n.担保书，证书，保单

参考例句：

• This warranty is good for one year after the date of the purchase of the product.本保证书自购置此产品之日起有效期为一年。
• As your guarantor,we have signed a warranty to the bank.作为你们的担保人，我们已经向银行开出了担保书。

10 volcanic   

adj.火山的；象火山的；由火山引起的

参考例句：

• There have been several volcanic eruptions this year.今年火山爆发了好几次。
• Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

11 justified   

a.正当的，有理的

参考例句：

• She felt fully justified in asking for her money back. 她认为有充分的理由要求退款。
• The prisoner has certainly justified his claims by his actions. 那个囚犯确实已用自己的行动表明他的要求是正当的。

12 resounding   

adj. 响亮的

参考例句：

• The astronaut was welcomed with joyous,resounding acclaim. 人们欢声雷动地迎接那位宇航员。
• He hit the water with a resounding slap. 他啪的一声拍了一下水。

13 inspection   

n.检查，审查，检阅

参考例句：

• On random inspection the meat was found to be bad.经抽查，发现肉变质了。
• The soldiers lined up for their daily inspection by their officers.士兵们列队接受军官的日常检阅。

14 ridge   

n.山脊；鼻梁；分水岭

参考例句：

• We clambered up the hillside to the ridge above.我们沿着山坡费力地爬上了山脊。
• The infantry were advancing to attack the ridge.步兵部队正在向前挺进攻打山脊。

15 longevity   

n.长命；长寿

参考例句：

• Good habits promote longevity.良好的习惯能增长寿命。
• Human longevity runs in families.人类的长寿具有家族遗传性。

16 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

17 gusts   

一阵强风( gust的名词复数 )； （怒、笑等的）爆发； （感情的）迸发； 发作

参考例句：

• Her profuse skirt bosomed out with the gusts. 她的宽大的裙子被风吹得鼓鼓的。
• Turbulence is defined as a series of irregular gusts. 紊流定义为一组无规则的突风。

18 reset   

v.重新安排，复位；n.重新放置；重放之物

参考例句：

• As soon as you arrive at your destination,step out of the aircraft and reset your wristwatch.你一到达目的地，就走出飞机并重新设置手表时间。
• He is recovering from an operation to reset his arm.他做了一个手臂复位手术，正在恢复。

19 terrain   

n.地面，地形，地图

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• He knows the terrain of this locality like the back of his hand.他对这一带的地形了如指掌。