《英语口语-第一架飞出地球大气层的飞机.docx》由会员分享，可在线阅读，更多相关《英语口语-第一架飞出地球大气层的飞机.docx（7页珍藏版）》请在金锄头文库上搜索。
1、 英语口语:第一架飞出地球大气层的飞机Today, Doug Johnson and Frank Oliver tell about the first airplane that flew out of the Earth”s atmosphere. It was designed to test equipment and conditions for future space flights. The plane was called the X-15.The pilot of the huge B-52 bomber plane pushes a button. From under
2、the plane”s right wing, the black sharp-nosed X-15 drops free. It is eleven-and-one-half kilometers above the Earth.Pilot Scott Crossfield is in the X-15”s only seat. When he is clear of the B-52, he starts the X-15”s rocket engine. And so begins the first powered flight of the experimental plane de
3、signed to take man to the edge of space.The X-15 flies high over the sandy wasteland of California”s Mojave Desert. Up, up it flies. After three minutes, its fuel has burned up. It is flying about two thousand kilometers an hour.Scott Crossfield”s voice tightens. His breathing becomes harder as the
4、plane pushes against the atmosphere. At that speed, the pressure is three times the force of gravity.Then the X-15 pushes over the top of its flight path. It settles into a long, powerless slide toward the landing field at Edwards Air Force Base.Designers of the X-15 have warned Crossfield about the
5、 landing. They say it will be like driving a race car toward a brick wall at one hundred sixty kilometers an hour, hitting the brakes, and stopping less than a meter from the wall. Crossfield lands the plane without any problem. His success shows, as one newspaper reports, that “The United States ha
6、s men to match its rockets. “That first flight of the X-15 took place in September, nineteen fifty-nine. But the story began in the nineteen forties with the X series of experimental aircraft.The first plane ever to fly faster than the speed of sound was the X-1 in nineteen forty-seven. United State
7、s government agencies and America”s airplane industry realized then that it was possible to build an even faster plane. It would reach hypersonic speeds - five times the speed of sound.The first proposal for this new research vehicle, the X-15, was made in nineteen fifty-four. The space agency, Air
8、Force and Navy jointly supported the program. They wanted a plane that could test conditions for future flights into space.The project moved quickly. The North American Aviation company won the competition to design and build the plane. The design would be part aircraft and part spacecraft. The comp
9、any took less than four years to produce three X-15s.The planes were not big. They were just fifteen meters long with wings less than seven meters across. They were designed to fly at speeds up to six thousand four hundred kilometers an hour. They were designed to reach heights of eighty kilometers.
10、 Their purpose was to explore some of the problems of manned flight, during short periods, in lower space. No one had ever done that before.The X-15 project had four major goals. It would test flight conditions at the edge of Earth”s atmosphere. It would leave the atmosphere briefly, then return, te
11、sting the effects of the extreme heat of re-entry. It would provide information on the controls needed in the near weightless environment of lower space. And it would answer a very important question: How would humans react to space flight?The X-15 was a new idea. And it was built with new methods.
12、It was covered in a new material called “inconel x.“ The material was a mixture of the metals nickel and chromium. It would protect the plane from high temperatures.There were new designs for the plane”s rocket engine, landing equipment and the small rockets needed to move it in space. There was a n
13、ew system of liquid nitrogen to keep the pilot cool and to resist the crushing force of gravity at high speeds. And there was a new fuel, a mixture of liquid ammonia and liquid oxygen.The X-15 was never designed to go into orbit. Nor could it take off from the ground. It was carried into the air by
14、a B-52 bomber. The big B-52 carried the small X-15 under its wing. It looked a little like a mother whale swimming with its baby.At about fifteen thousand meters, the B-52 released the X-15. After a few seconds, when the X-15 was safely away, the pilot started its rocket engine. The X-15 flew upward
15、 with unbelievable power.The three X-15s were flown one hundred ninety-nine times. Each flight was a new experiment. Planning took many days. The pilot spent fifty hours in a simulator - a copy of the plane on the ground - preparing for his ten-minute flight.Once the real flight began, the pilot had
16、 to remember everything he learned. He had to work quickly and exactly. All his movements were made against a force that could reach six times the power of gravity. He had to struggle to reach forward for the controls while being pushed back hard in his seat.A delay of even one second could affect the information being collected. It could change the plane”s path just enough to destroy the
