NASA deciphers mysterious Voyager I signal after months of silence

Experts at NASA have been working to decipher a mysterious sequence of zeros and ones transmitted by the Voyager I probe since November last year. The problem lies in the probe's flight data system (FDS), which has the crucial task of collecting spacecraft data and information from scientific instruments. Recently, one of the engineers succeeded in decrypting the signal.

Launched in 1977, the Voyager I probe embarked on a journey to explore the gas giants: Jupiter, Saturn, Uranus, and Neptune, followed by its twin, Voyager II. After their voyage around the outer planets ended in 1989, both probes set off towards the heliopause, the Sun's frontier where solar wind meets the pressure of galactic winds. This boundary, lying some 18 billion kilometres from the Sun, was crossed by Voyager I in 2012, entering interstellar space, with Voyager II following six years later.

As the designs of these probes are quite dated, it's not uncommon for some of their systems to fail. However, Voyager I faced a significantly challenging issue in December last year. NASA encountered disturbances in communication between the onboard flight data system (FDS) and the telemetry modulation unit (TMU), responsible for Earth communications, since November. Consequently, the mission managers lost insights into vital parameters, including the probe's propulsion, power, and control systems.

The FDS's role includes collecting and aggregating data from scientific instruments and information regarding the probe's status and location into a unified data package. However, the binary code data transmitted back to Earth had become indecipherable, described by NASA specialists as "digital gibberish". This puzzling situation persisted from November 14th last year.

A pivotal moment arrived in early March when a variation in the FDS's data stream was detected by the Voyager team. This led to the probe sending a series of numbers distinctly different from the usual "digital gibberish" following a command from Earth.

An engineer from NASA's Deep Space Network, responsible for the radio antennas communicating with Voyager I and II and other spacecraft, managed to decode the returned sequence, revealing it contained a snapshot of the FDS's entire memory.

This memory includes instructions for the spacecraft that can vary based on its status or commands from Earth, in addition to scientific and engineering data to be transmitted back to Earth.

The Voyager I rescue team is now set to compare this newly deciphered signal with the data received before the onset of "binary nonsense". Identifying discrepancies between the two may pinpoint the cause of the issue.

Hurtling through space approximately 25 billion miles from Earth, rectifying communication issues with Voyager I is a prolonged endeavour. It takes approximately 22.5 hours for a radio signal to travel from Voyager I to Earth, and an equal amount of time for a reply to reach back.

Source: Scientific American, Space.com