NASA has announced that communication with Voyager 1 has been successfully restored after a temporary blackout caused by its dwindling power supply. The spacecraft, currently traveling through uncharted space about 15.4 billion miles (24.9 billion kilometers) from Earth, experienced the issue in October when it automatically switched from its primary X-band radio transmitter to the less powerful S-band transmitter. This marked the first time since 1981 that the S-band had been used for communication. The switch disrupted the transmission of Voyager 1’s daily science and engineering data for nearly a month, but the spacecraft is now functioning normally, according to the agency.
Engineers discovered the problem when trying to send a command on October 16 to activate one of the spacecraft’s heaters. The command triggered Voyager 1’s fault protection system, designed to conserve its dwindling power supply by shutting down nonessential systems. The switch to the S-band transmitter lowered the rate at which Voyager 1 was sending data, which altered the signal that the Deep Space Network could detect.
According to NASA, this was the first time the fault protection system had been triggered since its initial activation in early 2022. The engineers resumed communications with the spacecraft this month, and it started collecting science data from two of its four operational instruments again last week. The team is now working on a few remaining tasks to bring the spacecraft fully back to normal, including resetting the system that synchronizes its three onboard computers.
In addition to the X-band transmitter, Voyager 1 also has an FDS, or flight data subsystem, that packages and formats data harvested by the probe’s various sensors and sends it to its central computer. Engineers got the FDS to work earlier this year after months of tinkering. But they still had to do serious sleuthing to get the X-band transmitter to work again.
NASA explained that Voyager 1’s X-band transmitter hasn’t been used for a long time because the S-band is better suited to transferring data across interstellar distances and can transmit more information faster.
In addition to the X-band and FDS, NASA has to reactivate a backup transmitter that has yet to be used since 1981 to broadcast an emergency signal to the Voyager mission team in case something goes wrong with the central computer system that runs the entire probe. This is just the latest innovative hack the NASA engineers have employed to overcome Voyager’s many communication challenges this year. Among other things, they’ve reactivated old thrusters to keep the probe’s antenna pointed at Earth and solved a computer glitch that silenced the probe’s stream of science data. It’s all part of the effort to keep this venerable spacecraft, which is now entering its fourth decade in operation, running as long as possible.