NASA engineers have turned off scientific instruments aboard Voyager 1 and Voyager 2 to extend their operational life. Voyager 1’s cosmic ray subsystem was deactivated on 25 February, while Voyager 2’s low-energy charged particle instrument will be shut down on 24 March.
Both spacecraft, launched in 1977, rely on a radioisotope power system that loses approximately 4 watts per year. To conserve energy, several instruments have been turned off over the decades. Without these recent shutdowns, the spacecraft would have had only a few months of operation left.
Voyager 1 entered interstellar space in 2012, followed by Voyager 2 in 2018. Together, they have travelled nearly 29 billion miles, making them the farthest human-made objects from Earth. Their instruments continue to collect unique data from beyond the solar system.
In the 1980s, NASA switched off several instruments after the spacecraft completed their study of the solar system’s giant planets. More recently, Voyager 2’s plasma science experiment was deactivated in October 2024. Voyager 1’s plasma instrument stopped working in 1980 and was shut down in 2007.
The instruments being shut down played a key role in space exploration. Voyager 1’s cosmic ray subsystem helped confirm its entry into interstellar space, while Voyager 2’s low-energy charged particle instrument measured ions and cosmic rays from the solar system and beyond.
Following these shutdowns, each spacecraft will have three operational instruments, which will drop to two in 2026. NASA aims to keep at least one instrument running into the 2030s, but unforeseen technical challenges could alter this timeline.
NASA scientists acknowledge that every day could be the last for the Voyagers. However, they continue efforts to maximise the spacecraft’s longevity, ensuring they gather as much interstellar data as possible before further instrument shutdowns become necessary.