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EXPLORATIONS - The X- 15 Rocketplane

时间:2006-03-06 16:00来源:互联网 提供网友:qwe   字体: [ ]

EXPLORATIONS - The X- 15 Rocketplane
By Marilyn Christiano

Broadcast: Wednesday, February 18, 2004



Explorations -- a program in Special English by the Voice of America.


The X-15 in flight.
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 bomber1 plane pushes a button. From under the plane's right wing, the black sharp-nosed X-Fifteen 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 designed 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 2000 kilometers an hour.

Scott Crossfield's voice tightens2. His breathing becomes harder as the 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 landing. They say it will be like driving a race car toward a brick wall at 160 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 has men to match its rockets. "


That first flight of the X-15 took place in September, 1959. 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 1947. United States 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 1954. The space agency, Air Force and Navy jointly3 supported the program. They wanted a plane that could test conditions for future flights into space.


The project moved quickly. The North American Aviation4 Company won the competition to design and build the plane. The design would be part aircraft and part spacecraft. The company took less than four years to produce three X-15.

The planes were not big. They were just 15 meters long with wings less than 7 meters across. They were designed to fly at speeds up to 6400 kilometers an hour. They were designed to reach heights of 80 kilometers. 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 briefly5, then return, testing 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. It was covered in a new material called "inconel x." The material was a mixture of the metals nickel6 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 new 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 being carried under the wing of a B-52.
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 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 15,000 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 with unbelievable power.


The three X-15 were flown 199 times. Each flight was a new experiment. Planning took many days. The pilot spent 50 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 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 pilot's chance of a safe landing.


The X-15 set height and speed records greater than those expected. The number three plane climbed more than 107 kilometers above the earth. The number two plane flew 7,232 kilometers an hour. That was more than seven times the speed of sound.

The X-15 was the first major investment by the United States in manned space flight technology. Much of what was learned from its flights speeded up the development of the space program.


The X-15 tested materials for space vehicles. It tested spacesuits worn later by America's astronauts. It tested instruments for controlling a vehicle in the weightlessness of space. And it proved that experienced pilots had the skills necessary to fly in space.

X-15 Pilot Neil Armstrong.
Twelve military and civilian7 test pilots flew the X-15. A few became astronauts.

The X-15 program lasted about ten years. There were about 200 flights. Some of the flights carried scientific experiments. One was a container on the end of the wing. It gathered dust and tiny meteoroids from the edge of space. Another was a set of special instruments that helped measure the effects of the sun's radiation on the outside of the aircraft.


The only tragedy connected with the X-15 program happened in 1967. The pilot was Michael Adams of the United States Air Force. It was his seventh X-15 flight.

Everything, at first, appeared to be normal. The plane reached a height of 80 kilometers. It was flying more than five times the speed of sound. Then, during a test of the wings, the plane moved sharply8 off its flight path. It dove9 toward Earth at great speed, spinning rapidly out of control. Atmospheric10 pressure was too great for the plane. It broke apart. The pilot did not survive.


The X-15 made its last flight in December, 1968. NASA needed money for its other projects. It decided11 to end the X-15 program. Many space experts disagreed with the decision. They felt the X-15 could have continued to provide new information about aviation and space.

Today, the X-15 hangs in the Air and Space Museum in Washington, D-C. It is in a memorial called Milestones12 of Flight. In the memorial, there is the X-1, the first airplane to fly faster than sound. And there is the "Spirit of Saint13 Louis," which Charles Lindbergh flew alone across the Atlantic Ocean. There also are copies of famous spacecraft like Russia's Sputnik and Pioneer Ten.

On the floor below these aircraft are three spacecraft command ships. One of them, the Apollo-Eleven, traveled to the moon just seven months after the last X-15 flight. It carried the man who became the first human to step on the moon, Neil Armstrong, a former X-15 pilot.



This Special English program was written by Marilyn Rice Christiano. Your narrators were Doug Johnson and Frank Oliver. Join us again next week for another Explorations program on the Voice of America.


1 bomber vWwz7     
  • He flew a bomber during the war.他在战时驾驶轰炸机。
  • Detectives hunting the London bombers will be keen to interview him.追查伦敦爆炸案凶犯的侦探们急于对他进行讯问。
2 tightens e55beaf60804ecfbd7ab248151f7a970     
收紧( tighten的第三人称单数 ); (使)变紧; (使)绷紧; 加紧
  • One set of provisions tightens emission standards. 一套使排放标准更加严格的规定。 来自英汉非文学 - 环境法 - 环境法
  • Requires no special tools or fittings; hand tightens to relief valve outlet. 不需要专用工具或管件;用手将其紧固到安全阀上即可。
3 jointly jp9zvS     
  • Tenants are jointly and severally liable for payment of the rent. 租金由承租人共同且分别承担。
  • She owns the house jointly with her husband. 她和丈夫共同拥有这所房子。
4 aviation aviation     
  • Ten years ago,they began to develop the aviation. 十年前,他们开始发展航空工业。
  • Pilots of large aircraft are masters of aviation.大型飞行器的驾驶员是航空学方面的专家。
5 briefly 9Styo     
  • I want to touch briefly on another aspect of the problem.我想简单地谈一下这个问题的另一方面。
  • He was kidnapped and briefly detained by a terrorist group.他被一个恐怖组织绑架并短暂拘禁。
6 nickel HGyxI     
  • Nickel can be used for making coins.镍可做成钱币。
  • May I have a nickel?能给我五分钱吗?
7 civilian uqbzl     
  • There is no reliable information about civilian casualties.关于平民的伤亡还没有确凿的信息。
  • He resigned his commission to take up a civilian job.他辞去军职而从事平民工作。
8 sharply UiRziL     
  • The plane dived sharply and rose again.飞机猛然俯冲而后又拉了起来。
  • Demand for personal computers has risen sharply.对个人电脑的需求急剧增长。
9 dove TuVzF5     
  • A dove is often used as a symbol of peace.鸽常作为和平的象征。
  • Paul seemed more impressed by the dove.保尔似乎对鸽子更感兴趣。
10 atmospheric 6eayR     
  • Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
  • Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。
11 decided lvqzZd     
  • This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
12 milestones 9b680059d7f7ea92ea578a9ceeb0f0db     
n.重要事件( milestone的名词复数 );重要阶段;转折点;里程碑
  • Several important milestones in foreign policy have been passed by this Congress and they can be chalked up as major accomplishments. 这次代表大会通过了对外政策中几起划时代的事件,并且它们可作为主要成就记录下来。 来自《简明英汉词典》
  • Dale: I really envy your milestones over the last few years, Don. 我真的很羡慕你在过去几年中所建立的丰功伟绩。 来自互联网
13 saint yYcxf     
  • He was made a saint.他被封为圣人。
  • The saint had a lowly heart.圣人有谦诚之心。
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