This false color photograph of Neptune was made from Voyager 2 images taken in January 1996. The image reveals the presence of a ubiquitous haze that covers Neptune in a semitransparent layer. Near the center of the disk, sunlight passes through the haze and deeper into the atmosphere, where some wavelengths are absorbed by methane gas, causing the center of the image to appear less red. Near the edge of the planet, the haze scatters sunlight at higher altitude, above most of the methane, causing the bright red edge around the planet. By measuring haze brightness at several wavelengths, scientists are able to estimate the thickness of the haze and its ability to scatter sunlight. The image is among the last full disk photos that Voyager 2 took before beginning its endless journey into interstellar space. (UPI Photo/NASA/JPL) | License Photo

PASADENA, Calif., May 18 (UPI) -- U.S. space agency scientists say they have identified the problem that distorted patterns of science data returning from the Voyager 2 spacecraft.

Engineers at NASA's Jet Propulsion Laboratory said the "flip of a bit" in the memory of an onboard computer appears to have caused the disruption. A value in a single memory location was changed from a 0 to a 1.


Officials said they plan to reset the bit to its normal state Wednesday.

The spacecraft was shifted into a mode that transmits only spacecraft health and status data after the unexpected change in the pattern of returning data. Although the spacecraft is in good overall technical health, NASA said the change in the data return pattern prevented mission managers from decoding science data.

Voyager 2 was launched in August 1977 about two weeks before its twin spacecraft, Voyager 1. The two spacecraft are the most distant human-made objects, now about 8-10 billion miles from Earth.

"Voyager 2's initial mission was a four-year journey to Saturn, but it is still returning data 33 years later," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena.

The Voyagers were built by JPL, which continues to operate both spacecraft.