NASA's twin Voyager probes, which have been exploring space for 47 years, are now shutting down some scientific instruments to conserve power and extend their missions. Voyager 1 and Voyager 2 are currently operating in interstellar space, the unexplored territory beyond our solar system.

On February 25, NASA’s Jet Propulsion Laboratory (JPL) instructed Voyager 1 to shut down its cosmic ray subsystem experiment, while Voyager 2 is scheduled to power off its low-energy charged particle instrument on March 24. This leaves each probe with three functioning science instruments.

The Voyager spacecraft, launched in 1977, initially carried 10 science instruments each. Over the years, as the plutonium power supply decayed, the mission team gradually turned off instruments to extend the probes' lifespan. Each year, the power supply loses around 4 watts.

Despite their original mission to study the outer planets, the Voyager probes have exceeded expectations by collecting invaluable data on the heliosphere and interstellar space. Scientists have utilized the twin spacecraft’s identical instruments to compare different environments in the cosmos.An illustration of Voyager shows some of the antennas and instruments aboard each spacecraft, including those still operating and those about to be shut off. NASA/JPL-Caltech

With the recent instrument shutdowns, the probes will still continue measuring cosmic rays, magnetic fields, and plasma waves. The team expects the Voyagers to keep operating until at least the 2030s, although unforeseen issues may arise.

“Every day could be our last,” said Linda Spilker, Voyager project scientist at JPL. “But that day could also bring another interstellar revelation. So, we’re doing everything possible to maximize the Voyagers' journey.”