NASA has made the difficult decision to turn off two science instruments aboard the Voyager spacecraft, ensuring that the longest-running space mission in history continues well into the 2030s. As power levels aboard the twin probes dwindle, mission engineers at the Jet Propulsion Laboratory (JPL) are taking extreme measures to stretch every remaining watt of energy, allowing Voyager 1 and Voyager 2 to continue their pioneering journey through interstellar space.
Launched in 1977, the Voyager probes remain the farthest human-made objects from Earth, with Voyager 1 now more than 15 billion miles away and Voyager 2 over 13 billion miles away. These latest power-saving efforts are a testament to the remarkable engineering behind these spacecraft, which have far outlived their original missions.
A Strategic Shutdown to Preserve the Mission
According to NASA’s Jet Propulsion Laboratory, engineers turned off Voyager 1’s cosmic ray subsystem experiment on February 25 and will shut down Voyager 2’s low-energy charged particle instrument on March 24. With this change, each probe will continue operating three science instruments, focusing on gathering valuable data about interstellar space.
Both spacecraft run on radioisotope thermoelectric generators (RTGs), which convert the heat from decaying plutonium into electricity. However, they lose about 4 watts of power per year, requiring careful energy management to keep the probes operational.
Suzanne Dodd, Voyager project manager at JPL, emphasized the importance of these energy-saving steps: “The Voyagers have been deep-space rock stars since launch, and we want to keep it that way as long as possible. But electrical power is 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.”
A Scientific Legacy Beyond the Solar System
Voyager 1 crossed into interstellar space in 2012, becoming the first human-made object to leave the heliosphere, the protective bubble created by the Sun’s solar wind. Voyager 2 followed in 2018, offering scientists their first comparative data set on how our solar system interacts with the vast space beyond.
Even with some instruments now powered down, the Voyagers will continue transmitting data that no other spacecraft can provide. Their remaining instruments will still monitor magnetic fields, plasma waves, and cosmic particles, helping scientists understand the boundaries of our solar system.
Patrick Koehn, Voyager program scientist at NASA Headquarters, praised the mission’s longevity: “The Voyager spacecraft have far surpassed their original mission to study the outer planets. Every bit of additional data we have gathered since then is not only valuable bonus science for heliophysics but also a testament to the exemplary engineering that has gone into the Voyagers—starting nearly 50 years ago and continuing to this day.”
How Much Longer Can Voyager Last?
The latest power adjustments should allow the probes to continue operating for another decade, with engineers predicting that at least one instrument on each spacecraft could remain active into the 2030s. However, their extreme distance from Earth means communication delays of over 23 hours for Voyager 1 and 19.5 hours for Voyager 2, making every command a slow and delicate process.
Linda Spilker, Voyager project scientist at JPL, acknowledged the uncertainty of the mission’s final years: “Every minute of every day, the Voyagers explore a region where no spacecraft has gone before. 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.”
