Word: spacecrafts
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...sort of radioactivity that is shown by natural iron meteorites. Cosmic rays from distant space have turned some of its iron atoms to unstable manganese 54, which gives off radiation while it is decaying to stable chromium 54. This is good proof that the object was part of a spacecraft that had orbited for a long time above the atmosphere, which stops most cosmic rays. The piece that fell on Manitowoc, Wis., probably came from the breakup of Sputnik IV, the five-ton Russian satellite that was launched on May 15, 1960 and disintegrated Sept...
...milestone: it effectively escaped from the earth's gravitation and became a satellite of the sun. But far out as it reached, it did not escape from the earth's control. Back on the fast-receding planet, 1,500,000 miles away, the scientists who built the spacecraft could still hear its radio voice, still send it orders...
...Goldstone control center in California's Mojave Desert, the scientists had been composing their message for more than a week. They knew with precision what maneuvers Mariner II must perform if it was to pass within a useful distance of Venus. The question was: Would the faraway spacecraft accept the orders, store them in its electronic memory and execute them properly at the proper time...
...spacecraft's electronic nervous sys tem took over and issued commands of its own, starting a one-hour warmup period. It turned off instruments and turned on guidance gyros. It swung the directional radio antenna aside to get it out of the blast of the mid-course rocket motor. At the end of the warmup, Mariner II was ready for the crucial maneuver of its long voyage. Replaying the commands from earth, it rolled 9.33 degrees and pitched its nose around for 139.83 degrees. This turned its mid-course rocket motor forward, putting it in position to slightly reduce...
...received at Goldstone. When the maneuvers were finished, and Mariner II had resumed its lonely cruise, Project Director Jack James analyzed the data. Sounding almost as if he did not believe it himself, he announced: "Everything worked exactly as planned." According to calculations based on radio measurements of the spacecraft's decreased speed, Mariner II had corrected its course neatly; instead of missing Venus by 233,000 miles, it would pass it on Dec. 14 at the ideal observation distance of 9,000 miles. Some peril of hostile space may yet put Mariner II out of action before...