VOA慢速英语--NASA Spacecraft to Study the Sun Up Close

 

The United States space agency will launch a spacecraft to explore the sun more closely than ever before on Saturday.

NASA’s Parker Solar Probe will fly through the hot solar atmosphere and come within just 6 million kilometers of the sun’s surface.

The spacecraft has a heat shield designed to resist temperatures of 1,370 degrees Celsius¹. The shield is unlike anything NASA has ever designed before.

Closer than ever before

The Parker Probe will get almost seven times closer to the sun than earlier spacecraft. To do this, it will fly past Venus seven times over seven years. Each pass will change the probe’s orbit by providing a gravity boost. It will move ever closer to the sun and straight into the corona², the sun’s outermost³ atmosphere.

By exploring the sun’s corona, scientists hope to learn why it is hundreds of times hotter than the sun’s surface. They will also study what drives the solar wind. Solar wind is the steady, high-speed stream of charged particles shooting off the corona into space.

Scientists expect the $1.5-billion mission to help them learn about both the Earth’s sun, and also the billions of other stars in the Milky⁴ Way and beyond.

“This is where we live,” said NASA solar astrophysicist Alex Young. “We have to understand and characterize this place that we’re traveling through.”

The project was proposed in 1958, the same year NASA was established. Now, “60 years later, and it’s becoming a reality,” said project manager Andy Driesman. Driesman is with Johns Hopkins University, which designed and built the spacecraft.

The technology for carrying out such a mission was not available until recently.

The Parker spacecraft has a 2.4-meter heat shield that is 11 centimeters thick. It is made of two carbon sheets, with carbon foam⁵ between them. The front has a white ceramic⁶ coating to reflect sunlight. It is expected to glow red when it experiences the extreme solar heat.

Almost everything on the spacecraft will be behind this shield, which is expected to keep its scientific instruments relatively⁷ cool.

Besides extreme temperatures, the spacecraft will also be traveling at a high speed. The probe will reach 690,000 kilometers per hour in the corona at its closest approach. That is the same as going from Chicago to Beijing in less than a minute.

The spacecraft will make its first flight past Venus in early October. Its first pass by the sun is expected in November.

The Parker Solar Probe is the first NASA spacecraft to be named after someone who is still alive. Eugene Parker is a 91-year-old professor at the University of Chicago. He predicted the existence of solar wind 60 years ago.

He plans to be at Cape⁸ Canaveral Air Force Station in the southern state of Florida to see the launch.

I’m Phil Dierking.

Words in This Story

approach - n. to move or become near or nearer to something or someone?

boost - n. to increase the force, power, or amount of (something)?

ceramic - adj. made of clay that has been heated to a very high temperature so that it becomes hard?

characterize - v. to describe the character or special qualities of (someone or something)?

foam - n. a soft material that is used to make many products?

probe - n. a device that is used to obtain information from outer space and send it back to Earth?

solar - adj. of or relating to the sun

1 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

2 corona   

n.日冕

参考例句：

• The corona gains and loses energy continuously.日冕总是不断地获得能量和损失能量。
• The corona is a brilliant,pearly white,filmy light,about as bright as the full moon.光环带是一种灿烂的珠白色朦胧光，几乎像满月一样明亮。

3 outermost   

adj.最外面的，远离中心的

参考例句：

• He fired and hit the outermost ring of the target.他开枪射中了靶子的最外一环。
• The outermost electron is shielded from the nucleus.原子核对最外层电子的作用受到屏蔽。

4 milky   

adj.牛奶的，多奶的；乳白色的

参考例句：

• Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。

5 foam   

v./n.泡沫，起泡沫

参考例句：

• The glass of beer was mostly foam.这杯啤酒大部分是泡沫。
• The surface of the water is full of foam.水面都是泡沫。

6 ceramic   

n.制陶业，陶器，陶瓷工艺

参考例句：

• The order for ceramic tiles has been booked in.瓷砖的订单已登记下来了。
• Some ceramic works of art are shown in this exhibition.这次展览会上展出了一些陶瓷艺术品。

7 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

8 cape   

n.海角，岬；披肩，短披风

参考例句：

• I long for a trip to the Cape of Good Hope.我渴望到好望角去旅行。
• She was wearing a cape over her dress.她在外套上披着一件披肩。