The United States launched the seventh in its ill-fated series of Ranger moon-probes yesterday (tuesday) from Cape Kennedy in Florida. After a faultless countdown, the Atlas-Agena rocket roared upwards from the launched carrying the Ranger into space.

It rose high over the Atlantic and went into a parking orbit. Twenty three minutes later the second stage fired and put the Ranger on course for the moon.

The Ranger carries six television cameras, and if all goes right, it will begin transmitting pictures of the moon's surface back to earth on Friday (July 31). It is hoped that during a 14-minute period, before the package crashes into the moon's surface at 5,800 miles an hour (9,330 KMH), it will take some 4 thousand pictures of the luna landscape.

Before the final, and most important phase begins, scientists in charge of the moon shot have today (Wednesday) fired a small steering rocket so that the Ranger does not strike the dark side of earth's nearest space neighbour.

The six previous Ranger shots have ended in failure. The most heart breaking failure came last January when Ranger Six, after an apparently flawless flight, failed to transmit pictures. Scientists said the trouble was a short-circuit during the launch, but the exact nature of the malfunction was never determined.