A Nasa spacecraft exploring interstellar space is sending back strange data that has left engineers puzzled.
Voyager 1, launched 45 years ago, is transmitting data from interstellar space that does not match what is actually happening on board, Nasa said on Wednesday.
The craft and its twin Voyager 2 have operated far longer than anyone expected and are the only spacecraft to collect data in interstellar space — a region that is not influenced by the Sun.
“A mystery like this is sort of par for the course at this stage of the Voyager mission,” said Suzanne Dodd, project manager for Voyager 1 and 2 at Nasa’s Jet Propulsion Laboratory in southern California.
“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. 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 (attitude articulation and control system), our team will find it.”
The spacecraft is operating normally, receiving and executing commands from Earth and is gathering and returning data.
However, data from the AACS, which controls the spacecraft’s orientation, does not reflect what is happening on board Voyager 1.
The AACS also keeps the spacecraft’s high-gain antenna pointed precisely at Earth, enabling it to send data home.
Nasa said that all signs suggest that the system is still working, but the telemetry data it is returning is invalid.
Voyager 1 is 23.3 billion kilometres from Earth, which means it takes about two days to send a message to Voyager 1 and get a response.
Voyager 2 is 19.5 billion km from Earth and is also operating normally.
Both spacecraft are helping shed light on the region outside of the solar system environment, and have helped search for the heliopause boundary — the point in space where interstellar space starts.