GoKawiilNASA Shuts Off Instrument on Voyager 1 to Keep Spacecraft Operating
On April 17, engineers at NASA’s Jet Propulsion Laboratory (JPL) in Southern California sent commands to shut down an instrument aboard Voyager 1 called the Low-energy Charged Particles experiment, or LECP. The nuclear-powered spacecraft is running low on power, and turning off the LECP is considered the best way to keep humanity’s first interstellar explorer going.
Mission engineers at NASA’s Jet Propulsion Laboratory in Southern California turned off the Low-energy Charged Particles experiment aboard Voyager 1 on April 17, 2026. NASA/JPL-Caltech
The LECP has been operating almost without interruption since Voyager 1 launched in 1977 — almost 49 years. It measures low-energy charged particles, including ions, electrons, and cosmic rays originating from our solar system and galaxy. The instrument has provided critical data about the structure of the interstellar medium, detecting pressure fronts and regions of varying particle density in the space beyond our heliosphere. The twin Voyagers are the only spacecraft that are far enough from Earth to provide this information.
Like Voyager 2, Voyager 1 relies on a radioisotope thermoelectric generator, a device that converts heat from decaying plutonium into electricity. Both probes lose about 4 watts of power each year. After almost a half-century in space, power margins have grown razor thin, requiring the team to conserve energy by shutting off heaters and instruments while making sure the spacecraft don’t get so cold that their fuel lines freeze.
During a routine, planned roll maneuver on Feb. 27, Voyager 1’s power levels fell unexpectedly. Mission engineers knew any additional drop in power could trigger the spacecraft’s undervoltage fault protection system, which would shut down components on its own to safeguard the probe, requiring recovery by the flight team — a lengthy process that carries its own risks.
The Voyager team needed to act first.
“While shutting down a science instrument is not anybody’s preference, it is the best option available,” said Kareem Badaruddin, Voyager mission manager at JPL. “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, sending back data from a region of space no other human-made craft has ever explored. The team remains focused on keeping both Voyagers going for as long as possible.”
Far-out plan
The choice of which instrument to turn off next wasn’t made in the heat of the moment. Years ago, the Voyager science and engineering teams sat down together and agreed on the order in which they would shut off parts of the spacecraft while ensuring the mission can continue to conduct its unique science. Of the 10 identical sets of instruments that each spacecraft carries, seven have been shut off so far. For Voyager 1, the LECP was next on that list. The team shut off the LECP on Voyager 2 in March 2025.
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