VOA标准英语2013--NASA: Humans Could Visit Asteroid in 2021

 

NASA: Humans Could Visit Asteroid¹ in 2021

These chunks² of ancient space rocks hold clues about the formation of the universe, pose threats to our planet, and present new territory for explorers.

NASA's proposed asteroid mission is a logical next leap for the space agency, says associate administrator³ for human exploration and operations Bill Gerstenmaier.

"It essentially⁴ fits right with what we were doing already.  This whole mission activity captures a lot of what we were doing before.  It captures the observation things.  It captures the electric propulsion, and it captures and utilizes⁵ our Orion [capsule] and SLS [rocket] just as it was envisioned," said Gerstenmaier.

Astronomers⁶ already are identifying and tracking near-Earth asteroids⁷ in an attempt to find potential threats, which will help as NASA chooses a target.

And the space agency's engineers are working on propulsion technologies that use sunlight to efficiently⁸ produce low thrust, reducing the amount of propellant needed for such a mission.

"We're going to capture and redirect a 7-10 meter, approximately 500-ton near-Earth asteroid to a stable orbit in translunar space, probably a deep retrograde orbit around the moon, and this will enable an astronaut mission to the asteroid as early as 2021," said Gerstenmaier.

A successful mission would show that humans can alter an asteroid's path, and be useful if one is found to be a danger to Earth.  

NASA says there is no threat to our planet if something goes wrong during this capture mission, because an asteroid this size would disintegrate⁹ before it struck the planet.  

Gerstenmaier says lunar orbit is stable enough that the asteroid possibly could stay in place for a century.

"So once we get the spacecraft and the object in this orbit, it's there for us to go visit multiple times in the future," he said.

Astronauts could use the Space Launch System and Orion space capsule that are being developed. Space explorers could spend about five days near the asteroid and venture out of the Orion capsule to collect samples that would be returned to Earth.   

Gerstenmaier says this will give astronauts and mission control experience working in deep space, far from Earth and the International Space Station.  

"In this case, we're going to have to make sure we have the right abort¹⁰ scenarios¹¹, the right redundancy in place, that we can tolerate being in this situation for up to five days.  So that helps us take a step toward the bigger missions that we want to do going forward," he said.

Bigger missions such as a manned voyage to Mars in the 2030s.

1 asteroid   

n.小行星；海盘车(动物)

参考例句：

• Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
• It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小，但这样的危险还是存在的。

2 chunks   

厚厚的一块( chunk的名词复数 )； （某物）相当大的数量或部分

参考例句：

• a tin of pineapple chunks 一罐菠萝块
• Those chunks of meat are rather large—could you chop them up a bIt'smaller? 这些肉块相当大，还能再切小一点吗？

3 administrator   

n.经营管理者，行政官员

参考例句：

• The role of administrator absorbed much of Ben's energy.行政职务耗掉本很多精力。
• He has proved himself capable as administrator.他表现出管理才能。

4 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

5 utilizes   

v.利用，使用( utilize的第三人称单数 )

参考例句：

• One highly successful approach utilizes a triplet aspheric lens array. 一种很成功的方法是利用一个三合非球面透镜阵列。 来自辞典例句
• The first utilizes a blend of finely ground ceramic powders. 第一种用的是一种磨细的陶瓷粉末混合物。 来自辞典例句

6 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

7 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

8 efficiently   

adv.高效率地，有能力地

参考例句：

• The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
• Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。

9 disintegrate   

v.瓦解，解体，（使）碎裂，（使）粉碎

参考例句：

• The older strata gradually disintegrate.较老的岩层渐渐风化。
• The plane would probably disintegrate at that high speed.飞机以那么高速飞行也许会四分五裂。

10 abort   

v.使流产，堕胎；中止；中止(工作、计划等)

参考例句：

• The captain instructed them to abort the mission.上尉指示他们中止执行任务。
• With this button the user can abort the audio sequence.用户可以用该按钮终止音频序列。

11 scenarios   

n.[意]情节；剧本；事态；脚本

参考例句：

• Further, graphite cores may be safer than non-graphite cores under some accident scenarios. 再者，根据一些事故解说，石墨堆芯可比非石墨堆芯更安全一些。 来自英汉非文学 - 环境法 - 环境法
• Again, scenarios should make it clear which modes are acceptable to users in various contexts. 同样，我们可以运用场景剧本来搞清楚在不同情境下哪些模式可被用户接受。 来自About Face 3交互设计精髓