Russia's latest test of a satellite-destroying weapon, conducted despite an appeal from President Carter for a ban on such weapons, apparently ended failure, U.S. intelligence sources believe.
A Soviet interceptor satellite went past its target satellite at a distance of less than 50 miles in the test last week, Russia's first in about five months, the sources say.
U.S. experts acknowledge it is difficult to tell whether such a test is a success or a failure without knowing Soviet technical objectives at the current stage of development. But U.S. study of the results has produced a consensus that the May 23 intercept test failed.
So far, it is believed, the Soviets have not attempted to destroy a target satellite in five testover the past year and a half.
Officials said the Soviets have not tried to target any American satellites, but have confined their tests to their own space vehicles.
Observation satellites are used by both countries to monitor each other's military developments, including testing strategic weapons, missile base construction and other important indicators.
U.S. scientists also are working on a U.S. system to knock out Soviet satellites, a project still in the research stage. The first flight tests are at least three years away, and the first deployment may be possible in five years.