One possible answer was recently given by the artificial satellites.

Artificial satellites have been very important in much of this research.

But there are special facts of life in an artificial satellite.

It needed to travel something over 12,000 miles per hour to reach the artificial satellite of Earth.

Some of the most important spacecraft today are artificial satellites.

The artificial satellite required little more than four hours for one revolution about its primary, the Earth.

There are artificial satellites, thousands of them, in orbit around the body.

Six years earlier, in 1957, the Soviets had launched the first artificial satellite.

It was a shock to realize the facts of life in an artificial satellite.

It was of the kind used by humans to put artificial satellites into orbit.