The beginnings of Space exploration

Space Shuttle
   Engineers had experimented with rockets, which could fly at enormous speeds, in the 1930's and 1940's. Finally, in 1957, Soviet engineers devel­oped one that could fly fast enough to break out of the earth's gravitational pull. The Soviet rocket placed a small artificial satellite, called Sputnik, into orbit around the earth. In 1959 the Soviets crashed a rocket into the moon. In 1961 they built one with enough power to put a person in orbit around the earth. The United States responded with its own huge program for space exploration. In 1969 this effort succeeded in transporting two American astronauts to the moon.
   The main results of space exploration in the 1970's came from unmanned spacecraft. Orbiting satellites transmitted television, telephone, and radio signals around the earth, vastly improving communication. Orbiting cameras transformed weather forecasting. The American Voyager spacecraft provided important new information about the makeup of other planets.
   A new phase of space exploration began with the launch of the first space shuttle, Columbia, in 1981. By 1986 reusable shuttles, which contained elements of both the traditional space capsule and the airplane, had completed two dozen successful missions. Early that year, however, the explosion of the shuttle Challenger and the lost of its crew temporarily halted the human explo­ration of space.