To Keep the Voyager 1 Spacecraft on Its Interstellar Journey, NASA Turned Off One of Its Few Remaining Instruments
The probe launched almost 50 years ago and is the farthest human-made object from Earth. Shutting down one of its scientific devices will help it conserve energy and continue traveling toward the edge of the solar system
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In 1977, NASA launched an ambitious mission: Two spacecraft called Voyager 1 and Voyager 2 blasted off to investigate Jupiter and Saturn. They’re still gathering data today—now, in interstellar space—and they continue to hurtle toward the edge of the solar system.
Voyager 1 is now about 15.8 billion miles from Earth, making it the most distant human-made object. But to keep the decades-old probe chugging along, NASA shut down one of its scientific instruments on April 17, per a statement.
“We didn’t design them to last 30 years or 40 years, we designed them not to fail,” former Voyager project manager John Casani said in a NASA statement in 2024.
Part of that entails closely managing the spacecrafts’ power. Both Voyagers get energy from a generator that turns heat from decaying plutonium into electricity, and they lose about four watts of power every year. At this point, their power margins are extremely slim, meaning the team must selectively turn off heaters and instruments to save energy while also preventing the spacecraft from getting too cold.
Quick fact: Main mission complete
Voyager 1 flew by Jupiter on March 5, 1979, and Saturn on Nov. 12, 1980. Voyager 2 zipped past the planets on July 9, 1979, and Aug. 25, 1981, respectively. After completing their main goals, the second spacecraft also visited Uranus and Neptune.
Voyager 1 is particularly low on power. In February, the levels suddenly dropped so much that any further decrease could start an automated system that would try to protect the spacecraft by shutting down some of its components. However, that would require NASA scientists to follow up with a long and risky recovery process.
To avoid that outcome, engineers at NASA’s Jet Propulsion Laboratory (JPL) turned off Voyager 1’s Low-energy Charged Particles experiment (LECP), which measures ions, electrons and cosmic rays that come from the solar system and galaxy. Data from the instrument has helped scientists better understand the structure of the interstellar medium, the gas, dust and radiation at the margins of the solar system and between other star systems. The Voyager spacecraft have been the only probes able to take these measurements, since Voyager 1 reached interstellar space—where the sun no longer influences the environment—in 2012 and Voyager 2 in 2018. The second probe’s LECP got the boot in March 2025.
“While shutting down a science instrument is not anybody’s preference, it is the best option available,” Kareem Badaruddin, Voyager mission manager at JPL, says in the recent statement. “Voyager 1 still has two remaining operating science instruments—one that listens to plasma waves and one that measures magnetic fields. They are still working great.”
Both Voyager probes started with the same ten instruments, and prior to the latest shutdown, seven had been turned off in each.
NASA scientists had already determined the order in which spacecraft instruments would be powered down, so Voyager 1’s LECP was simply the next to go. Because of its distance from Earth, shutdown commands took around 23 hours to reach the probe, and the actual power-down took about 3 hours and 15 minutes.
It might not be a permanent end for the particle-measuring device, however. The team is working on a larger energy-saving strategy for both probes. Dubbed “the Big Bang,” the move would involve simultaneously turning off several devices and switching them to lower-power alternatives.
Voyager 1 might get the Big Bang treatment as early as July. Success would mean scientists might have the opportunity to bring its LECP back to life. NASA even left part of the instrument alive to boost their chance of eventually turning it back on.
All these efforts should hopefully keep both Voyager probes chugging along on their journey. “I always tell people, my personal goal is to have a spacecraft that celebrates its 50th anniversary from launch,” Suzanne Dodd, program manager for Voyager at JPL, told Smithsonian magazine’s Mark Strauss in 2019.
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