1 . Round and Round They Go
Space is becoming more crowded. On December 3, a Falcon 9 rocket made by SpaceX thundered into the sky. On board were 64 small satellites, more than any American company had launched before in one go.They have a variety of uses, from space-based radar to the monitoring of radio-frequency emissions.
These objects are part of the latest breed of low-Earth-orbit (LEO) satellites. This launch is just a taste of what is planned. SpaceX and OneWeb, a communications firm, plan to launch satellites in their thousands, not hundreds. The pair are set to double the total number of satellites in orbit by2027.
For that to happen,however,three worries must be overcome. Debris (碎片) is the most familiar concern.As long ago as 1978, Donald Kessler,a scientist at NASA, proposed a situation in which, when enough satellites were packed into low-Earth orbits, any collision could cause a chain reaction which would eventually destroy all space craft in its orbital plane (平面).The syndrome which bears Mr. Kessler's name weighs heavily on the minds of executives at the new satellite firms.Debris could cause entire tracts (广阔的一片) of space to be unusable for decades.
Solutions exist. One is to grab malfunctioning satellites and pull them down into-Earth's atmosphere.Another is to monitor space more intensively for debris; a US Air Force programme called Space Fence is due to start in 2019. But technology is only part of the answer. Rules are needed to govern the safe disposal (清除) of old satellites from low-Earth orbit. The United States' Federal Communications Commission is revising its regulations with this in mind. Other countries should follow suit.
Cyber-security is a second, long-standing worry. Hackers could take control of a satellite and seal intellectual property, redirect data flows or cause a collision. The satellite industry has been slow to respond to such concerns. But as more of the world's population comes to rely on the infrastructure of space for access to the internet, the need for action intensifies.
The third issue follows from the first two. If a simple mistake or a cyber-attack can cause a chain reaction which wipes out hundreds of billions of dollars of investment, who is liable?Underwriters (保险商) are studying the plans of firms that wish to operate large numbers of satellites.But there is a long way to go before the risks are well understood,let alone priced.
As space becomes more commercialized, mind-bending prospects open up: packages moved across the planet in minutes by rocket rather than by plane, equipment sent to other small planets, passengers launched into orbit and beyond. All that and more may come,one day. But such activities would raise the same questions as LEO satellites do. They must be answered before the space economy can truly develop.
1. What can we learn about LEO satellites from the passage?| A．They are supposed to limit the space economy. |
| B．They are expected to increase in large numbers. |
| C．They are designed to move beyond the Earth as far as possible. |
| D．They are mainly intended to bring internet connectivity to remote areas. |
| A．depending entirely on the modern technology |
| B．monitoring the movement of spaceships carefully |
| C．strengthening rules to remove old satellites safely |
| D．destroying all the satellites with problems instantly |
| A．Measure. |
| B．Increase. |
| C．Spread. |
| D．Repeat. |
| A．Lack of satellite regulations. |
| B．Loss of intellectual property. |
| C．Crisis of confidence in the field. |
| D．Slow response of satellite industry. |
| A．It should be further confirmed for it ownership. |
| B．It should be continued because of its advantages. |
| C．It should be done carefully to avoid potential risks. |
| D．It should be stopped in face of the space economy. |
2 . Scientists have not found any signs of life on Mars yet,but they say a robotic vehicle called “Curiosity” is helping them learn a lot about the planet’s history and climate.
Curiosity landed on Mars in August 2012 after travelling through space for more than eight months.It was sent to Mars by scientists from NASA in the United States.
Curiosity is about the size of a car and has six wheels.It also has a robotic arm,cameras,and instruments that allow it to examine things it finds on the surface.Then it sends the information back to the earth.
Curiosity’s main task is to find out if anything could live on Mars,either now or in the past.On Nov.2,NASA scientists held a press conference (新闻发布会) to discuss what Curiosity had found in its first two months on Mars.
Curiosity has found soil that is similar to the sand formed by volcanoes (火山) on the earth.Scientists say that studying the minerals in Martian soil will help them understand what conditions were like on the planet in the past.Curiosity also found smooth stones like the ones found on river beds and seashores on the earth,where their rough edges have been worn down by water.Mars is very cold and dry now,but scientists say the smooth stones tell them that a river used to run through the place where they were found.
Curiosity has been testing the atmosphere around Mars for a type of gas called methane (甲烷),but so far it has not found any.On the earth,most methane is produced by plants or animals.Methane on Mars might indicate that some type of tiny plants or animals lived there.
Curiosity is the fourth robotic vehicle to be sent to Mars.It will continue to explore the planet for about two years.
1. Which of the following descriptions about Curiosity is TRUE?| A．It landed on Mars in January 2012. |
| B．It is small in size and has four arms. |
| C．It took over eight months to arrive in Mars. |
| D．It was sent to Mars by scientists from Russia. |
| A．there’s no air on Mars | B．Mars is warm and wet now |
| C．the soil on Mars is rich | D．there used to be water on Mars |
| A．smooth stones | B．rivers |
| C．robotic vehicles | D．volcanoes |
| A．some tiny animals once lived on Mars |
| B．there are no plants or animals on Mars now |
| C．the atmosphere around Mars is full of methane |
| D．Curiosity is designed to test the atmosphere around the earth |
| A．Humans benefit a lot by going to Mars. |
| B．Scientists will stop the research on Mars soon. |
| C．It is possible to build an earth-like environment on Mars. |
| D．A robotic vehicle helps scientists get useful information from Mars. |
3 . The ringed planet Saturn has 53 known moons. And another one may be on the way. NASA’s Cassini-Huyens space probe has spotted（发现）a small shape in Saturn’s outermost ring. It suggests the existence of a new moon. The moon has not been directly spotted yet, but scientists have already given it a nickname---Peggy.
The probe’s findings were published in the journal Icarus. Casssini has been observing the ringed planet and its surroundings since 2004. Saturn is a big and powerful world. With a diameter of 74, 732 miles, it is 9½ times the size of Earth. It spins very quickly, and take only 11 hours to spin fully on its axis(轴). The planet is located about 885.9 million miles from the sun and has an average temperature of -285 degrees Fahrenheit.
Peggy will be joining a large community. Saturn has thousands of rings. The outermost ring, called the A Ring, is the largest and brightest. It measures 750 miles long and 6 miles wide. Saturn’s rings are made up of rock, dust and ice, and are constantly gathering space matter. As this material gathers and clumps together, moons are born.
If Peggy is a new moon, it is also a tiny one, measuring only 0.5 miles in diameter. But there is no telling how big this baby will grow over time. “We’ve never seen anything like this before,” said astronomer Carl Murray in a statement . He is the lead author of the Icarus report. “We may be looking at an act of birth, where this object is leaving the rings and heading off to be a moon in its own right.” Once that happens, it will be given a formal name.
However, this mini moon may be one of Saturn’s last. The formation of all its moons, new and old, big and small, has used up much of the rings’ raw material. After 4.5 billion years, Saturn may have finally revealed all its babies.
1. Which of the following is TRUE about Saturn?| A．It has hundreds of rings. | B．It is much bigger than Earth. |
| C．It moves as quickly as Earth. | D．Its 53rd known moon is called Peggy. |
| A．Saturn’s biggest moon. | B．Saturn’s innermost ring. |
| C．Saturn’s outermost ring. | D．Saturn’s new moon Peggy. |
| A．Peggy may disappear soon |
| B．Peggy may grow bigger and bigger |
| C．Peggy will have its own moon soon |
| D．Peggy is the new moon’s formal name |
| A．Saturn will have more and more moons |
| B．Saturn’s rings will have more and more material |
| C．Saturn’s rings may disappear in 4.5 billion years |
| D．Saturn won’t have too many moons younger than Peggy |
| A．Saturn’s baby moon | B．The future of Saturn |
| C．Saturn’s beautiful rings | D．Interesting facts about Saturn |
