NASA’s Voyager 1 space probe sent a fully readable report to Earth for the first time in five months. On April 20, the mission team received a message from the device containing data about the status of their system. Although the probe still cannot send back readable science data, the mission team at least understands exactly what happened to Voyager 1 and now has a chance to repair it.

Thirty-five years after its launch in 1977, Voyager 1 became the first human-made object to leave the Solar System and enter interstellar space. Six years after this event, in 2018, its twin sister, Voyager 2, repeated this success. Fortunately, Voyager 2 is still operational and sending data back to Earth.

Both devices are the only human-made objects that explore space outside the influence of the Sun. But on November 14, 2023, after 11 years of interstellar space exploration and 24 billion km from Earth, Voyager 1 began sending an unintelligible binary code home. The devices communicate with Earth using binary code, and Voyager 1 sent completely unreadable data.

In March, NANA engineers managed to send a dedicated team to Voyager 1, which forced the probe to return its entire onboard storage unit (FDS) to Earth. These data showed that an error occurred in the transfer of information read by the device, which occurred as a result of the corruption of one of the memory chips, representing 3% of the total amount of FDS memory. Unfortunately, the chip contained software code that made it impossible to use Voyager 1’s science and telemetry data.

It is obvious that NASA engineers cannot replace the damaged Voyager 1 memory chip. However, they can remotely transfer corrupted code to another part of the FSD memory. Since none of the probe’s memory segments are large enough to store the entire code, mission engineers must break the code into pieces and store them separately from each other. Additionally, the relevant storage sections must be configured in such a way that adding corrupted code does not cause these memory areas to stop working individually and does not execute the code as a whole. NASA will also need to update all references to the new location of the broken code.

On April 18, the NASA team began moving the corrupted code to another location in the FDS memory. The process turned out to be very slow, as it took 22.5 hours for the radio signal to reach the probe and another 22.5 hours for the return signal to be received from the probe.

However, on April 20, mission experts confirmed that Voyager 1’s memory modification was successful. For the first time in five months, scientists were able to establish a communication channel with the probe and receive the latest data on its status. In the coming weeks, engineers will work to fine-tune the rest of the FDS memory software and hope to restore regions of the system responsible for compiling and sending invaluable scientific data collected outside the Solar System.