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　　進入專題：2015年聽力風暴來襲，英語四級每日一聽！

　　Experts say ground-based radar is unable to track more than 70% of aircraft flights. But that has continued to be the usual method since the 1940s. This is one reason the Malaysia Airways Flight 370 plane has not been found.

　　Now, there are plans to deploy aircraft tracking satellites into space so that no plane will ever be "lost" again.

　　The company Iridium Communications plans to have sixty-six new satellites orbiting the planet. They call the system of satellites the NEXT constellation. The NEXT satellites will be able to receive an airplane's location signal every few seconds.

　　MH370 flew out of the range of Malaysian military radar while over the Indian Ocean early last year. The plane has yet to be found.

　　Don Thoma is the CEO of the aircraft tracking company Aireon. He says MH370 showed the limits of the current tracking system.

　　"It highlighted to the rest of the world and to the public at large what the aviation industry already knew -- that over 70% of the world doesn't have surveillance. Aircrafts aren't tracked flying over a major portion of the world."

　　The satellites' receivers update every few seconds. They receive information from equipment in the pilot area of the aircraft. Iridium monitors the satellites from a control center in Virginia.

　　Aircraft safety rules require large distances between planes since they cannot currently be tracked over entire oceans. But once the NEXT satellites are setup in 3 years, planes will be able to fly closer to each other. Airlines will then be able to save money on fuel. Passengers will see more flights and more direct flights to locations around the world.

　　The company is also building an emergency operations center 10 kilometers north of Shannon Airport in Ireland. If an aircraft is lost, the airline or rescue organization could contact the center for the plane's last flight track. Tony Merrigan is with the Irish Aviation Authority.

　　"That's unique now because it will be within eight seconds of when the last contact was made, the distances would have been narrowed down, in the case of MH370, if that was available at the time."

　　I'm Jonathan Evans.

　　VOA's Carolyn Presutti wrote this report. Jonathan Evans adapted it for Learning English. Caty Weaver was the editor.

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