Transmits only confused data

NASA finds error in “Voyager 1” computer

Since November 2023, the data that "Voyager 1" (pictured) transmits to Earth has been unusable.(Bild: NASA/JPL-Caltech)

Twelve years ago, the "Voyager 1" probe left our solar system. Despite this, it regularly transmitted scientific data to Earth until recently. But since November 2023, this data has been unusable. Now the US space agency NASA has found the cause.

As NASA recently reported on its website, engineers at the Jet Propulsion Laboratory in Pasadena discovered that a small part of the memory in one of the computers on board Voyager 1 was causing the probe to send unreadable, confused data to Earth.

This was caused by a computer known as the flight data subsystem (FDS), which is actually responsible for compiling the probe's scientific and technical data before the telemetry modulation unit (TMU) and the transmitter send the data to Earth.

Three percent of the memory damaged
At the beginning of March, the JPL team issued a so-called POKE command (an instruction in the BASIC programming language, note) to request the probe to send back an extract from the FDS memory, which contains the computer's software code and variables (values used in the code that can change depending on the command or status of the probe, note). As a result, it was discovered that around three percent of the FDS memory was corrupted, preventing the computer from working normally.

The reason for the damage is unclear
The JPL team suspects that a single chip, which is responsible for storing part of the affected part of the FDS memory, is not working. NASA reports that it is not possible to determine with certainty what exactly caused the problem. It is possible that the chip was hit by a high-energy particle from space or that it has simply become defective after 46 years.

Although it could take weeks or months, engineers at JPL, which manages satellites and space probes for NASA, are optimistic that they will find a way to get the FDS working normally without the unusable memory hardware so that Voyager 1 can resume providing scientific and engineering data.

Probe to continue transmitting data until 2025
Voyager 1 is expected to continue transmitting data until 2025, but then the probe's power source will be exhausted. The most distant man-made object from Earth will continue to fly through space and will not pass the nearest star, a dim sun with the catalog number AC+79 3888 in the constellation Ursa Minor, for more than 38,000 years.

(Bild: NASA/JPL-Caltech)

In the extremely unlikely event that an alien civilization should ever encounter the earthly ambassador, the "Voyager" probes each carry a gold-plated copper record (pictured above) with the title "Lutes of Earth" as well as a record player with instructions for use.

Probes have been hurtling through space since 1977
"Voyager 1" (traveler) was launched on September 5, 1977, the twin probe "Voyager 2" around two weeks earlier, on August 20. The two probes hurtled through space at more than 60,000 kilometers per hour. At a distance of almost 24.3 billion kilometers (as of the end of March 2024) from Earth, "Voyager 1" is humanity's most distant messenger.