45 years after its launch, NASA’s Voyager 1 is still traveling beyond our Solar System. However, the veteran spacecraft is suddenly sending back unusual data that is baffling its engineers.

While the probe is still operational, readouts from its attitude articulation and control system – AACS for short – do not appear to match the spacecraft’s motions and orientation, suggesting the ship is unsure of its location in space.

As it maintains the craft’s antenna pointed directly at our planet, the AACS is critical for Voyager to give NASA data on its surrounding interstellar environment.

“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.” Suzanne Dodd, a project manager for Voyager 1 and 2 at NASA’s Jet Propulsion Laboratory, said in a statement.

The Voyager 2 probe, Voyager 1’s twin, is operating correctly, according to NASA.

Voyager 1, which was launched in 1977 to study the outer planets of our solar system, has outlasted predictions and continues to relay data back to Earth. In 2012, the pioneering ship exited our Solar System and entered interstellar space. It has already travelled 14.5 billion miles from Earth, making it the farthest human-made object.

According to NASA, the AACS aboard Voyager 1 is relaying arbitrarily produced data that does not “reflect what’s actually happening onboard.”

Even though system data shows otherwise, the spacecraft’s antenna appears to be correctly oriented — it is receiving and executing NASA orders and transmitting data back to Earth. It stated that the system problem has not yet caused the aged spacecraft to enter “safe mode,” in which it performs just critical activities.

It takes light 20 hours and 33 minutes to get to Voyager’s current interstellar location, so a round-trip message between the space agency and Voyager takes two days.