The bad news is the Voyager 1 mission team still isn't sure why the 47-year-old spacecraft is sending garbled messages from the outer reaches of the solar system. The good news is that the communication link isn't entirely severed across a gap of 15 billion miles, as a recent "poke" elicited science and engineering data as well as a readout of the flight data system's memory, which is now being scoured for clues to the problem, per Space.com. The spacecraft reliably sent back data in binary code for years until November when it began spewing out only alternating 1s and 0s, suggesting an issue with the flight data system's telemetry modulation unit.
As Voyager 1 is still responding to commands, the mission team sent a "poke" asking the flight data system to run various software sequences in the hope of uncovering a glitch, CNN reports. On March 3, the team received a signal in an incorrect format, which an engineer with NASA's Deep Space Network was able to decode beginning on March 7. The signal included "science or engineering data for downlink" as well as a readout of the entire flight data system's memory, including "its code, or instructions for what to do, as well as variables, or values used in the code that can change based on commands or the spacecraft's status," NASA says in a blog post.
NASA says the team will compare the readout to the last one received before the issue arose to "look for discrepancies in the code and the variables to potentially find the source of the ongoing issue." Such a readout would reveal, for instance, if a command inadvertently moved the spacecraft's antenna in the wrong direction—an issue discovered with Voyager 2 last year, per CNN. Granted, whatever insights are gained, "using that information to devise a potential solution and attempt to put it into action will take time," NASA notes. It takes 22.5 hours to send a command to Voyager 1, the farthest spacecraft from Earth, and another 22.5 hours to receive a response. (More Voyager 1 stories.)