Scientists Rescue Voyager 2 Probe on Edge of Solar System

An error in Voyager 2's memory threatened its mission on the edge of the solar system. The 33-year old probe has since been successfully fixed. (Source: NASA)

Voyager 2 is currently traveling through at the edge of our solar system. (Source: NASA)

Reset of memory turns out to be just what the computer doctor ordered

Voyager 2 was launched 33 years ago and currently remains on course, traveling out of the solar system. It is currently 8.6 billion miles (13.8 billion km) from Earth, passing through the heliosphere, a magnetic bubble that surrounds our solar system. It continues to transmit data, even as it passes through this volatile region.

However, three weeks ago the probe started transmitting garbled messages to Earth. NASA program administrators put the spacecraft in an engineering mode, restricting it to only sending health updates to Earth, while they diagnosed the issue.

It turns out the problem was caused by a single bit in the probe's memory that had flipped. The memory was successfully reset to the proper value and normal operations resumed. In near-Earth satellites, bit flip occasionally occurs due to solar radiation. Since Voyager 2 was so far from the Sun, though, it's unclear exactly what caused the bit flip instance.

NASA's Voyager 2 project manager Ed Massey comments, "In some spacecraft that are closer to the sun one could think of single event upsets caused by solar activity. But we're so far away, it's hard to say that's what caused it. We're like 93, 94 AU out."

The command to reset the probe was set on May 19, and by May 22 the probe was back in action talking to Earth in its usual fashion.

Voyager 2 was launched in 1977. Its primary mission was to study Saturn. Along the way the craft made flybys of all the other outer gas plants -- Jupiter, Uranus and Neptune -- thanks to a planetary alignment that only occurs once every 176 years. Even though the probe is leaving the solar system, its sensor measurements are still yielding clues that scientists can use to determine the nature and origin of the heliosphere.