NASA engineers have restored communication with Voyager 1, the most distant spacecraft in history, after resolving a communication issue that had persisted for five months.
After discovering the issue, the mission team attempted sending commands to restart the spacecraft’s computer system and learn more about the underlying cause of the problem. They sent a command called a “poke” to Voyager 1 on March 1 to get the flight data system to run different software sequences in the hopes of finding out what was causing the glitch.
On March 3, the team noticed that activity from one part of the flight data system stood out from the rest of the garbled data. While the signal wasn’t in the format the Voyager team is used to seeing when the flight data system is functioning as expected, an engineer with NASA’s Deep Space Network was able to decode it.
The team determined that a single chip responsible for storing part of the system’s memory, including some of the computer’s software code, wasn’t working properly. The loss of the code on the chip caused Voyager 1’s science and engineering data to be unusable.
Since there was no way to repair the chip, the team opted to store the affected code from the chip elsewhere in the system’s memory. They were able to divide the code into sections and store it in different spots within the flight data system.
After determining the code necessary for packaging Voyager 1’s engineering data, engineers sent a radio signal to the probe commanding the code to a new location in the system’s memory on April 18.
On April 20, the team received Voyager 1’s response indicating that the clever code modification had worked, and they could finally receive readable engineering data from the probe once more.
Within the coming weeks, the team will continue to relocate other affected parts of the system’s software, including those responsible for returning the valuable science data Voyager 1 is collecting.
Initially designed to last five years, Voyager 1 and its twin, Voyager 2, launched in 1977 and are the longest operating spacecraft in history. Both are in interstellar space and are the only spacecraft ever to operate beyond the heliosphere, the sun’s bubble of magnetic fields and particles that extends well beyond the orbit of Pluto.
