NASA has begun shutting down key instruments aboard the legendary Voyager spacecraft as their power supply dwindles, marking the final stretch of one of humanity’s greatest space exploration missions. With Voyager 1 now over 24 billion kilometers from Earth and Voyager 2 close behind, engineers are making difficult decisions to keep these pioneering probes operational for as long as possible.
A Race Against Time
Launched in 1977, the twin spacecraft were initially tasked with a four-year mission to explore Jupiter and Saturn. Decades later, they remain operational, transmitting invaluable data from interstellar space—the first and only spacecraft to do so. However, after nearly half a century, their power sources are fading, forcing NASA to selectively turn off scientific instruments to conserve energy.
On March 5, 2024, NASA confirmed it had shut down Voyager 1’s cosmic ray subsystem experiment, an instrument that played a crucial role in detecting when the probe crossed the boundary of the heliosphere in 2012. Later this month, on March 24, Voyager 2’s low-energy charged particle instrument will also be deactivated.
These decisions are part of an ongoing effort to stretch the lifespan of both probes, ensuring that at least a few instruments remain active for as long as possible.
Why NASA is Powering Down Voyager’s Instruments
Both Voyager spacecraft rely on radioisotope thermoelectric generators (RTGs), which convert the heat from decaying plutonium into electricity. Over time, this power supply has gradually weakened. To offset the loss, NASA has already shut down heaters and other non-essential systems to keep the remaining instruments running.
“The Voyagers have been deep space rock stars since launch, and we want to keep it that way as long as possible,” said Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory. “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.”
The instruments set to be shut down rely on a rotating platform that has exceeded its expected lifetime by an incredible margin. Originally designed to operate for 500,000 steps, the mechanism has now performed an astonishing 8.5 million steps—far beyond what engineers had anticipated.
The Final Years of Voyager
Despite these setbacks, three instruments on each Voyager will remain active for at least another year, with Voyager 1’s low-energy charged particle instrument expected to continue collecting data until late 2025. Voyager 2’s cosmic ray subsystem will likely follow in 2026.
Beyond that, the future is uncertain. If all goes well, NASA hopes to keep the Voyagers operational into the 2030s, but the probes are aging, and malfunctions could occur at any time.
“Every minute of every day, the Voyagers explore a region where no spacecraft has gone before,” Linda Spilker, Voyager project scientist at JPL, added. “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.”
For now, Voyager 1 and 2 remain humanity’s longest-running and farthest-reaching space explorers, continuing to send messages from the vast unknown.
