VOA科学技术2023--NASA to Launch Spacecraft to Observe Metal-rich Asteroid

NASA to Launch Spacecraft to Observe Metal-rich Asteroid¹

The American space agency NASA is preparing to launch a spacecraft designed to observe an asteroid made mostly of metal.

The launch of the vehicle, called Psyche², is set for October 12 from Kennedy Space Center in Florida.

The spacecraft will fly to an asteroid also called Psyche. It orbits the sun between Mars and Jupiter. NASA says the asteroid was discovered by an Italian astronomer³ in 1852. Since it was the 16th asteroid discovered, it is sometimes also called 16 Psyche.

Psyche will be NASA's first trip, or mission, to an asteroid that contains a large amount of metal. Past missions explored asteroids⁴ made mostly of rock or ice.

Astronomers⁵ say the asteroid Psyche is about 280 kilometers at its widest point. They believe it may be part of a center, or core, of a planetesimal. This is an object thought to be the metallic⁶ remains⁷ of an early rocky planet. Scientists think Psyche is made up mostly of iron and nickel, similar to Earth's center.

NASA believes the asteroid could have separated during violent crashes that happened during our solar system's early creation. Scientists think data collected on the asteroid could provide new details about how rocky planets, including Earth, formed.

But NASA says the object could also turn out to be something else, such as "a different kind of iron-rich body that formed from metal-rich material somewhere in the solar system."

The space agency expects Psyche to travel about 3.6 billion kilometers over six years to reach the asteroid. If the spacecraft reaches its target as planned in August 2029, it will then start orbiting the object for at least two years.

Once in orbit, the mission team will examine data gathered by several science instruments aboard the spacecraft. Psyche will take pictures, map the asteroid's surface and collect data on what materials are contained in the object.

NASA says once Psyche separates from its launch vehicle, it will use a different kind of propulsion system never tried in missions beyond the moon.

The system to be used is called solar electric propulsion. Large solar panels will be extended outward from the main part of the spacecraft to collect light from the sun. The panels then change, or convert, this sunlight into electricity that powers the spacecraft's thrusters.

Psyche will depend on solar electric propulsion to reach its target. NASA describes the thrust as "gentle," but strong enough to push the spacecraft through its long trip. The spacecraft is also set to get a gravitational push when it passes by Mars in May 2026.

NASA said experiments have shown that solar electric propulsion can be highly effective. Scientists estimate Psyche's thrusters "could operate nearly nonstop for years without running out of fuel."

In addition, NASA says Psyche will be carrying nearly 1,000 kilograms of propellant, xenon gas, in its tanks. Xenon is also used in automobile⁸ headlights and some televisions. Agency engineers have estimated the mission would need to burn through about 15 times that amount of propellant if the Psyche spacecraft used traditional chemical thrusters.

Lindy Elkins-Tanton, with Arizona State University, is the lead investigator⁹ for the mission. She said NASA had always planned on having Psyche use an electric propulsion system. "Without it, we wouldn't have the Psyche mission," Elkins-Tanton said.

NASA says the Psyche mission also includes a technology demonstration¹⁰ involving a laser-based data communications system. This experiment is designed to "test the ability of lasers to transmit data at increased rates beyond the moon."

The technology to be tested in the demonstration is known as "optical communications." It is meant to one day replace the radio communication systems long used by NASA to transmit data between Earth and space. NASA says a laser-based communication method will permit the agency to send and receive data faster and more effectively.

Words in This Story

asteroid – n. an object made of rock and metal that orbits the sun, but is smaller than planets

propulsion – n. a force that pushes something forward

panel – n. a flat piece of equipment that uses the sun's light or heat to create electricity

thruster – n. an engine that produces propulsion by releasing a jet of fluid or a stream of particles

transmit – v. to send

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 psyche   

n.精神；灵魂

参考例句：

• His exploration of the myth brings insight into the American psyche.他对这个神话的探讨揭示了美国人的心理。
• She spent her life plumbing the mysteries of the human psyche.她毕生探索人类心灵的奥秘。

3 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。

4 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。

5 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》

6 metallic   

adj.金属的；金属制的；含金属的；产金属的；像金属的

参考例句：

• A sharp metallic note coming from the outside frightened me.外面传来尖锐铿锵的声音吓了我一跳。
• He picked up a metallic ring last night.昨夜他捡了一个金属戒指。

7 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

8 automobile   

n.汽车，机动车

参考例句：

• He is repairing the brake lever of an automobile.他正在修理汽车的刹车杆。
• The automobile slowed down to go around the curves in the road.汽车在路上转弯时放慢了速度。

9 investigator   

n.研究者，调查者，审查者

参考例句：

• He was a special investigator for the FBI.他是联邦调查局的特别调查员。
• The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。

10 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。