Anomaly telemetry on Voyager 1
We are investigating a mystery with Voyager 1.
While the 45-year-old spacecraft continues to return scientific data and otherwise function normally, some system readings don’t exactly reflect what’s happening on board.
The engineering team is trying to solve a mystery: the interstellar explorer works normally, receives and executes commands from Earth, as well as collecting and returning scientific data. But the probe’s articulation and attitude control (AACS) readings do not reflect what is actually happening on board.
The AACS has been monitoring the orientation of the spacecraft for 45 years. Among other activities, it keeps Voyager 1’s high-gain antenna pointed precisely at Earth, allowing it to send data home. All signs suggest the AACS is still working, but the telemetry data it is returning is invalid. For example, the data might appear to be randomly generated or not reflect any possible state the AACS might be in.
The problem did not activate any on-board fault protection systems, designed to put the spacecraft into “safe mode,” a state in which only essential operations are performed, giving engineers time to diagnose a problem. The Voyager 1 signal has also not weakened, which suggests that the high-gain antenna remains in the prescribed orientation with the Earth.
The team will continue to monitor the signal closely as it continues to determine if the invalid data is coming directly from the AACS or from another system involved in producing and sending telemetry data. Until the nature of the problem is better understood, the team cannot predict whether this could affect how long the spacecraft can collect and transmit scientific data.
Voyager 1 is currently 23.3 billion kilometers from Earth, and it takes light 20 hours and 33 minutes to travel that difference. This means it takes about two days to send a message to Voyager 1 and get a response, a delay the mission team is well used to.
The team may not find the source of the anomaly and adapt to it instead. If they find the source, they may be able to fix the problem through software changes or potentially using one of the spacecraft’s redundant hardware systems.
It wouldn’t be the first time the Voyager team has relied on backup hardware – in 2017, Voyager 1’s primary thrusters showed signs of decay, so engineers switched to another set of thrusters that were originally used during the meetings. spacecraft planetariums. Those thrusters worked, despite being unused for 37 years.
Credit NASA JPL