More science instruments are being shut down on the Voyager probes as engineers attempt to eke out the power and keep them running for years to come.
It should not come as a surprise that NASA is turning off instruments. The shutdowns were already planned to take place as the venerable probes enter the final years of their operational life. The team hopes that if it takes action now, the robotic spacecraft could still be operating with at least one science instrument into the 2030s.
Voyager 1's cosmic ray subsystem – a suite of three telescopes designed to study cosmic rays, including protons from the galaxy and the Sun, by measuring their energy and flux – was shut down last week. Voyager 2's low-energy charged particle instrument is due for deactivation later this month.
This means that it should be 2026 before another instrument must be turned off on both spacecraft. For Voyager 1, its low-energy charged particle instrument will need to be deactivated. In 2026, the cosmic ray subsystem aboard Voyager 2 will be turned off.
The Voyagers carry an identical set of 10 science instruments, which are being gradually shut down. Some were geared toward planetary flybys, and so are no longer needed.
Suzanne Dodd, Voyager project manager at the Jet Propulsion Laboratory (JPL), called the probes "deep space rockstars," but noted that electrical power was running low. "If we don't turn off an instrument on each Voyager now, they would probably have only a few more months of power before we would need to declare end of mission."
The steps taken should mean that the Voyagers will endure past the half-century mark – a testament to the designers and makers of the spacecraft. However, there is always a chance that an unforeseen incident might bring an earlier end to the mission. Engineers recovered Voyager 1 in 2024 after a memory glitch left the probe spouting gibberish. The spacecraft also abruptly went silent last year after a command to turn on a heater tripped a fault protection system due to low power levels.
The probes are in uncharted territory both in terms of location and operation. Each command, which takes 23 hours to reach Voyager 1 and 19-and a half for Voyager 2, is ever more risky, particularly considering it'll take the same time to get a response back, during which time anything could happen.
"Every minute of every day, the Voyagers explore a region where no spacecraft has gone before," said Linda Spilker, Voyager project scientist at JPL. "That also means every day could be our last. But that day could also bring another interstellar revelation. So, we're pulling out all the stops, doing what we can to make sure Voyagers 1 and 2 continue their trailblazing for the maximum time possible." ®