Voyager 2, which has been traveling through the solar system since the late '70s, has suffered a data formatting glitch that is preventing NASA from interpreting the content of its scientific data transmissions. Control and diagnostic transmissions are unaffected, which should enable the engineers at NASA's Jet Propulsion Laboratory to troubleshoot the problem, provided they're patient—it currently takes nearly 13 hours for transmissions from Earth to catch up with the probe.

According to a statement released by the JPL, the problem first became apparent on April 22nd. Data from the scientific transmission, which currently reports on the conditions at the very edge of the solar system, began coming through with improper formatting, making it impossible to interpret the contents. Engineering data is still intelligible, so the JPL staff is expecting that it will be possible to figure out what's going wrong and introduce a fix. Serious attempts at repair were delayed by a planned roll maneuver, and only started on Friday. With a round-trip time of over a day, however, progress will undoubtedly be slow.

According to an Associated Press report, engineers think that there's been a fault in the memory that stores the formatted data prior to transmission. This either corrupted its current contents, or has introduced some bad bits into the onboard memory. It should be possible to either reset the bad memory, or program the system to stop using the errant hardware entirely.

Voyager 2 is currently the second-most distant human-made object, trailing its twin, Voyager 1, by about 3 billion kilometers (Voyager 1 is now 16.9 billion kilometers—about 10.5 billion miles—from Earth). Right now, the probes are near the turbulent sector of space where the solar wind pushes up against interstellar space. Both probes are expected to cross into interstellar space within the next few years, providing our first in-place observational data from outside the solar system. They'll also record what happens at the boundary itself—they may cross it several times, given that its precise location fluctuates with changes in solar activity.