What a difference a bit makes. NASA engineers believe they
have traced the cause of Voyager 2′s gibberish to single flip of bit in the
“A value in a single memory location was changed from a 0 to
a 1,” said JPL’s Veronia McGregor.
Voyager 2 left Earth on Aug. 20, 1977 to explore Jupiter and
Saturn. It successfully finished that mission, then flew by Uranus and Neptune
before heading into interstellar space.
It is currently traveling through heliopause — a region of space
where the sun’s influence ebbs and interstellar forces begin to dominate.
Voyager 2 and its twin, Voyager 1, are both expected to
enter interstellar space — the first human-made objects to do so — in the
next five years.
Earlier this month, engineers suspended Voyager 2′s science
measurements because of an unexpected problem in its communications
stream. A glitch in the flight data system, which
formats information for radioing to Earth, was believed to be the problem.
Engineers were able to replicate the glitch in a computer lab, showing that a
single bit flip was responsible. NASA plans to reset Voyager’s memory tomorrow.
The spacecraft is so far away it takes nearly 13 hours for a
radio signal from Earth, traveling at the speed of light, to reach it, and
another 13 hours to receive a response.
Image: Artist’s rendering of Voyager 2 in the outer regions of the heliosphere, the magnetic bubble around the solar system generated by the solar wind. Credit: NASA.