Launched back in 1977 on a mission to explore the outer Solar System and interstellar space, NASA’s Voyager 1 probe has started sending signals that have baffled scientists back on Earth.
This development occurred as the craft is now travelling some 23.3 billion kilometres away from our planet.
This week, however, NASA announced that while the probe continues to operate normally and keeps "gathering and returning science data", the readouts from Voyager 1’s attitude articulation and control system (AACS), which controls the craft’s orientation, "don’t reflect what’s actually happening onboard".
While it would appear that the AACS itself is working, the telemetry data it returns is "invalid", NASA notes, and this issue hasn’t yet triggered any fault protection system on board the spacecraft.
Suzanne Dodd, project manager of Voyagers 1 and 2 at NASA’s Jet Propulsion Laboratory, said that "a mystery like this is sort of par for the course at this stage of the Voyager mission".
"The spacecraft are both almost 45 years old, which is far beyond what the mission planners anticipated. We’re also in interstellar space – a high-radiation environment that no spacecraft have flown in before", she elaborated. "So there are some big challenges for the engineering team. But I think if there’s a way to solve this issue with the AACS, our team will find it".
She further explained that the team may either find the source of the anomaly and a way to deal with it – either via software changes or by utilising one of the probe’s redundant hardware systems – or they may not identify it and instead adapt to it.