For more than 30 years, Voyager 1 and Voyager 2 have been traveling though space gathering scientific data from our solar system. After traveling about 14 billion kilometers, Voyager 2 has become confused.
Scientists and technicians at the Jet Propulsion Laboratory (JPL) first realized there was a problem on April 22, 2010 when confusing data started coming back from Voyager 2, which is now reporting on what is at the edge of the solar system. The JPL engineers believe that the problem lies within the memory buffer and storage that holds the scientific data before it is transmitted — for sure it is some fault within the data collection, storage, and transmittal system. This happens occasionally when a cosmic ray causes bits to flip or become totally corrupted. Fortunately, the command and control system has not been affected, so there should be no problem running diagnostics on the data system and determining a fix.
At approximately 14 billion kilometers, communications with Voyager 2 take 13 hours per trip (or 26 hours round-trip); this makes repairing the system a slow task. And, since several maneuvers were already scheduled, repairs could not begin until May 7, 2010. Engineers hope that, during the process of fixing this corruption, they are able to repair and decode the information already captured by the probe that was sent back corrupted.
For more specifics, read the JPL's news release about Voyager 2.More about Voyager 1 and Voyager 2
Voyager 1 is estimated to break through the heliosphere (i.e., the bubble around the solar system that the solar rays create) in approximately five years; Voyager 2 should follow soon after. It is also estimated that each probe will re-enter and leave the solar system several times, as the heliosphere changes in shape and size frequently. This will be advantageous in that no one really knows what happens at the solar system's boundary, and these two probes will be able to record it several times.