While engineers investigated the condition of an apparently failed tape recorder on the Galileo spacecraft, the chief scientist predicted on Friday that it would still be possible to achieve at least half of the mission's scientific objectives in exploring Jupiter without the machine - but there would be fewer pictures.
"The impact of a possible loss of the tape recorder is not as bad as people assumed when we first heard about the problem," said Torrence Johnson, the project scientist at the Jet Propulsion Laboratory in Pasadena, Calif.
Flight controllers, meanwhile, radioed commands to the spacecraft in an effort to determine if the tape recorder, critical to storing photographic and other scientific data for later transmission, has indeed malfunctioned and if there is any prospect of restoring it. The results of the test may not be known until early next week.
The Galileo spacecraft, launched in 1989, is scheduled to rocket into an orbit of Jupiter on Dec. 7 and spend at least two years exploring the giant planet and its four largest satellites. Jupiter, with a diameter of about 88,000 miles, is the largest planet in the solar system and the fifth in distance from the Sun.
The spacecraft's first serious setback occurred four years ago, when the main antenna failed to open properly, sharply reducing the amount of data the Galileo could return to Earth. Then on Oct. 11, after the spacecraft had taken a picture of Jupiter and its moons from 22 million miles away, the tape recorder failed to stop rewinding.
Scientists were counting on the tape recorder to help make up for the antenna failure.