VOA慢速英语 EXPLORATIONS - Risk of Crossed Paths Grows in Increa（在线收听）

VOICE ONE:

I’m Steve Ember.

VOICE TWO:

And I’m Faith Lapidus with EXPLORATIONS in VOA Special English. This week, we tell about a growing threat to airplanes around the world. And we hear about objects in space that are threatening satellites and the International Space Station.

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VOICE ONE:

On January fifteenth, US Airways flight fifteen forty-nine was leaving La Guardia airport near New York City. Everything seemed normal and the weather was good that day. But as the passenger jet climbed to about nine hundred meters in the air, something happened.
　
A crane removes the US Airways plane from the Hudson River in January

Captain Chesley Sullenberger reported that both of his plane’s engines had struck birds. The engines soon lost all power. The plane was unable to return to the airport. So Captain Sullenberger made a quick decision to land the plane on the freezing water of the nearby Hudson River. The emergency landing was performed perfectly.

Captain Sullenberger’s actions saved the lives of one hundred fifty-five passengers and crew.But the incident brought attention to a real and growing threat to air safety.

VOICE TWO:

Bird strikes happen all over the world. And they are not rare. Bird Strike Committee USA gathers information about such incidents in the United States and around the world. The group is a volunteer committee. It includes members from the Federal Aviation Administration, Department of Agriculture, Defense Department and the aviation industry.

Bird Strike Committee USA says bird strikes cause about six hundred million dollars in damage to American civilian and military aviation each year. The group says fifty-six thousand incidents were reported to the F.A.A. between nineteen ninety and two thousand four. More than seven thousand six hundred bird and other wildlife strikes were reported for civilian aircraft in two thousand seven.

But studies show only about twenty percent of bird strikes to civilian aircraft are reported. These incidents can be deadly. The organization says wildlife strikes have led to the deaths of two hundred nineteen people around the world since nineteen eighty-eight.

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VOICE ONE:
　
A 1999 picture of a small plane in Atlantic City, New Jersey, that was damaged by a bird

In the United States, aviation officials have taken measures to reduce the risk from bird strikes and dangers from other wildlife since the nineteen sixties.

Federal Aviation Administration rules require airports to study the risks of wildlife to safe airport operations. These studies must consider wildlife activity up to about three thousand meters above an airport and eight kilometers around it. They also must provide detailed information about nearby water and environmental issues that could cause wildlife to gather near an airport.

Michael O’Donnell is director of the F.A.A. Office of Airport Safety and Standards. He says there are about five hundred sixty commercial service airports in the United States. Not all airports need wildlife control plans. But the ones that do work closely with government agencies.The Department of Agriculture, for example, provides biologists to help study wildlife that could be a danger to air travel.

VOICE TWO:

The number of reported bird strikes has increased since nineteen ninety. One reason is that there are more birds. Protected species have reproduced in huge numbers. For example, permanent populations of Canada geese in North America have increased three hundred percent in eighteen years to four million birds.

Other birds have spread quickly across areas with heavy air traffic. The European starling was released for the first time in the United States over one hundred years ago. Today, there are more than one hundred fifty million of these birds. They are called “feathered bullets” because of their high body density.

Another reason for the increase in bird strikes is the growing popularity of air travel in the United States. Since nineteen eighty, flights have increased by about two percent each year. In two thousand seven, the number reached twenty-eight million.

Airports have used many different methods to reduce the number of birds and other wildlife nearby. These include lasers, noise makers and, when necessary, killing problem animals.

VOICE ONE:
　
A plane in Medford, Oregon, that was damaged by a bird strike in 2003

The F.A.A. is also seeking ways to help planes avoid birds. Since the emergency landing of flight fifteen forty-nine, special radars have received a lot of attention. The air travel agency is currently testing a radar system at the international airport in Seattle, Washington. The F.A.A. plans to test new radar systems at airports in Chicago, Illinois; Dallas, Texas; and New York City.

Michael O’Donnell says the F.A.A. is spending between seven hundred fifty thousand and one million dollars a year on radar research.

The United States space agency already uses an Aircraft Birdstrike Avoidance Radar at the Kennedy Space Center in Florida. The radar is built by the company DeTect of Panama City, Florida. It was put in place to help protect the space shuttle from bird strike damage. And the Air Force currently uses radar developed by DeTect at several bases.

Technology also has a part in the growing threat from birds. Today’s large passenger planes have fewer but more powerful engines than older models. That means it is easier for planes with only two engines to strike a flock of birds and lose power in both engines.

But Michael O’Donnell says the number of serious bird strike incidents has remained at or below two hundred each year. He credits this to better education and knowledge about the issue.

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VOICE TWO:

From bird strikes, we turn to another kind of threat caused by objects in space. The number of man-made objects in Earth orbit has been growing each year. These include satellites, old rocket parts and other pieces of spacecraft.

Nicholas Johnson is chief scientist for orbital debris for the United States space agency. He says there are more than three hundred thousand small objects or pieces of debris in orbit that are larger than one centimeter. Any one of these could cause damage to a spacecraft. This is because orbital debris travels at speeds of thirty-two thousand kilometers an hour or more. Even a very small object can be a major threat.

VOICE ONE:
　
A space shuttle window is inspected for damage by orbital debris

Space debris made news on March twelfth when a part of an old rocket motor about ten centimeters in size threatened the International Space Station. NASA warned the three astronauts inside about one hour before the object was to reach the area of the station.

Americans Mike Fincke and Sandra Magnus and Russian Yury Lonchakov quickly moved into the Soyuz emergency escape vehicle as a safety measure. They spent eleven tense minutes in the capsule.

It is unclear how close the object came to the station. But the piece was big enough to have caused severe damage. On March twenty-second, NASA again ordered the astronauts on the linked space station and shuttle Discovery to move out of the way of another piece of debris from a rocket.

The space station has been hit in the past by very small debris. But these strikes caused little damage, mostly to the station’s solar energy collectors.

VOICE TWO:

A more costly incident took place on February tenth. An old Russian military satellite and a United States communications satellite crashed into each other eight hundred kilometers above Siberia in Russia.

Russia had launched the Kosmos satellite in nineteen ninety-three. But it had not operated for ten years. It was one of hundreds of inactive satellites that remain in orbit.

The American Iridium thirty-three satellite was used for telephone communications. It was owned by Iridium Satellite, a company based in Bethesda, Maryland. The company said the loss caused little interference with its service at the time. Before the collision, Iridium had a group of sixty-six satellites in orbit.

The United States Space Surveillance Network is closely studying the collision involving the Russian satellite. The agency is part of United States Central Command. It follows over eighteen thousand pieces of debris as small as the size of a baseball.

VOICE ONE:
　
A computer image from the European Space Agency shows an artist's version of orbital debris above Earth

The collision of the Russian and American satellites was the first of its kind in over fifty years of space travel. It spread hundreds of pieces of debris.

But the biggest debris-causing event took place in January, two thousand seven. China tested an anti-satellite missile by destroying one of its weather satellites. The test broke the satellite apart into at least two thousand eight hundred identifiable pieces. The debris now circles the Earth in orbits from two hundred kilometers to over three thousand eight hundred kilometers.

Currently, there is no treaty to control the spread of space debris. Scientists have proposed many ideas for cleaning up space. They include nets, giant collecting arms and powerful laser beams that would move or destroy space junk. But for now, these are just ideas. And, as more nations launch spacecraft, the risk of debris strikes will only grow.

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VOICE TWO:

This program was written and produced by Mario Ritter. I'm Faith Lapidus.

VOICE ONE:

And I'm Steve Ember.Transcripts, MP3s and podcasts of our programs are at voaspecialenglish.com. Join us again next week for Explorations in VOA Special English.