High and fast: the X-15 reached the edge of space_美文

High and fast: the X-15 reached the edge of space

Everything, at first, appeared to be normal. The plane reached a height of eight kilometers. It was flying more than five times the speed of sound. Then, during a test of the wings, the plane moved sharply off its flight path. It dove toward Earth at great speed, spinning rapidly out of control. Atmospheric 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 decided 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 Milestones of Flight. In the memorial, there is the X-1, the first airplane to fly faster than sound. And there is the "Spirit of St. Louis," which Charles Lindbergh flew alone across the Atlantic Ocean. There also are copies of famous spacecraft like Russia’s Sputnik and Pioneer 10.

On the floor below these aircraft are three spacecraft command ships. One of them, the Apollo-11, 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.