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ANNCR:

Explorations -- a program in Special English by the Voice ofAmerica.

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Today, Doug Johnson and FrankOliver tell about the first airplane that flew out of the Earth'satmosphere. It was designed to test equipment and conditions forfuture space flights. The plane was called the X-15.

VOICE ONE:

The pilot of the huge B-52 bomber plane pushes a button. Fromunder the plane's right wing, the black sharp-nosed X-Fifteen dropsfree. It is eleven-and-one-half kilometers above the Earth.

Pilot Scott Crossfield is in the X-15's only seat. When he isclear of the B-52, he starts the X-15's rocket engine. And so beginsthe first powered flight of the experimental plane designed to takeman to the edge of space.

VOICE TWO:

The X-15 flies high over the sandy wasteland of California'sMojave Desert. Up, up it flies. After three minutes, its fuel hasburned up. It is flying about 2000 kilometers an hour.

Scott Crossfield's voice tightens. His breathing becomes harderas the plane pushes against the atmosphere. At that speed, thepressure is three times the force of gravity.

Then the X-15 pushes over the top of its flight path. It settlesinto a long, powerless slide toward the landing field at Edwards AirForce 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 at160 kilometers an hour, hitting the brakes, and stopping less than ameter from the wall. Crossfield lands the plane without any problem.His success shows, as one newspaper reports, that "The United Stateshas men to match its rockets. "

VOICE ONE:

That first flight of the X-15 took place in September, 1959. Butthe story began in the nineteen-forties with the 'X' series ofexperimental aircraft.

The first plane ever to fly faster than the speed of sound wasthe X-1 in 1947. United States government agencies and America'sairplane industry realized then that it was possible to build aneven faster plane. It would reach hypersonic speeds -- five timesthe speed of sound.

The first proposal for this new research vehicle, the X-15, wasmade in 1954. The space agency, Air Force and Navy jointly supportedthe program. They wanted a plane that could test conditions forfuture flights into space.

VOICE TWO:

The project moved quickly. The North American Aviation Companywon the competition to design and build the plane. The design wouldbe part aircraft and part spacecraft. The company took less thanfour years to produce three X-15.

The planes were not big. They were just 15 meters long with wingsless than 7 meters across. They were designed to fly at speeds up to6400 kilometers an hour. They were designed to reach heights of 80kilometers. Their purpose was to explore some of the problems ofmanned flight, during short periods, in lower space. No one had everdone that before.

VOICE ONE:

The X-15 project had four major goals.

It would test flight conditions at the edge of Earth'satmosphere. It would leave the atmosphere briefly, then return,testing the effects of the extreme heat of re-entry. It wouldprovide information on the controls needed in the near weightlessenvironment of lower space. And it would answer a very importantquestion. How would humans react to space flight.

VOICE TWO:

The X-15 was a new idea. And it was built with new methods. Itwas covered in a new material called "inconel x." The material was amixture of the metals nickel and chromium. It would protect theplane from high temperatures.

There were new designs for the plane's rocket engine, landingequipment and the small rockets needed to move it in space. Therewas a new system of liquid nitrogen to keep the pilot cool and toresist the crushing force of gravity at high speeds. And there was anew fuel, a mixture of liquid ammonia and liquid oxygen.

VOICE ONE:

The X-15 was never designed to gointo orbit. Nor could it take off from the ground. It was carriedinto the air by a B-52 bomber. The big B-52 carried the small X-15under its wing. It looked a little like a mother whale swimming withits baby.

At about 15,000 meters, the B-52 released the X-15. After a fewseconds, when the X-15 was safely away, the pilot started its rocketengine. The X-15 flew upward with unbelievable power.

VOICE TWO:

The three X-15 were flown 199 times. Each flight was a newexperiment. Planning took many days. The pilot spent 50 hours in asimulator -- a copy of the plane on the ground -- preparing for histen-minute flight.

Once the real flight began, the pilot had to remember everythinghe learned. He had to work quickly and exactly. All his movementswere made against a force that could reach six times the power ofgravity. He had to struggle to reach forward for the controls whilebeing pushed back hard in his seat.

A delay of even one second could affect the information beingcollected. It could change the plane's path just enough to destroythe pilot's chance of a safe landing.

VOICE ONE:

The X-15 set height and speed records greater than thoseexpected. The number three plane climbed more than 107 kilometersabove 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 inmanned space flight technology. Much of what was learned from itsflights speeded up the development of the space program.

VOICE TWO:

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

Twelve military and civilian testpilots flew the X-15. A few became astronauts.

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

VOICE ONE:

The only tragedy connected with the X-15 program happened in1967. The pilot was Michael Adams of the United States Air Force. Itwas his seventh X-15 flight.

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

VOICE TWO:

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

Today, the X-15 hangs in the Air and Space Museum in Washington,D-C. It is in a memorial called Milestones of Flight. In thememorial, there is the X-1, the first airplane to fly faster thansound. And there is the "Spirit of Saint Louis," which CharlesLindbergh flew alone across the Atlantic Ocean. There also arecopies of famous spacecraft like Russia's Sputnik and Pioneer Ten.

On the floor below these aircraft are three spacecraft commandships. One of them, the Apollo-Eleven, traveled to the moon justseven months after the last X-15 flight. It carried the man whobecame the first human to step on the moon, Neil Armstrong, a formerX-15 pilot.

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ANNCR:

This Special English program was written by Marilyn RiceChristiano. Your narrators were Doug Johnson and Frank Oliver. Joinus again next week for another Explorations program on the Voice ofAmerica.