NASA's Jet Propulsion Laboratory says engineers are trying to diagnose a problem in data from the aging Voyager 2 spacecraft near the edge of the solar system.
A JPL statement Thursday says there appears to be a problem in a system that formats data sent to Earth. An unexpected change has prevented mission managers from decoding science data.
For now, Voyager 2 has been placed in a mode to only transmit spacecraft health and status data.
Voyager 2 and its twin, Voyager 1, were launched in 1977 and are now the most distant human-made objects after a tour of the outer planets.
Voyager 2 is 8.6 billion miles from Earth. Voyager 1 is about 2 billion miles farther out and is expected to leave the solar system and reach interstellar space in about five years.
Copyright 2010 The Associated Press.