Nasa has shut down Voyager 1’s charged particles instrument to conserve power as the spacecraft, now over 15 billion miles from Earth, continues its interstellar journey.
Nasa has taken the significant step of shutting down Voyager 1’s Low-Energy Charged Particles (LECP) instrument to conserve dwindling power. This decision comes as the nearly 49-year-old spacecraft continues its journey through interstellar space, now more than 15 billion miles from Earth.
Engineers at Nasa’s Jet Propulsion Laboratory (JPL) in Southern California issued commands on Friday to turn off the LECP experiment, which has been operational almost continuously since the spacecraft’s launch in 1977. The move is a response to the spacecraft’s annual power loss of approximately 4 watts, as mission managers strive to extend its operational lifespan.
“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 shutdown highlights the delicate balancing act faced by the Voyager team, as both Voyager 1 and its twin, Voyager 2, age far beyond their original mission timelines. Both spacecraft are powered by radioisotope thermoelectric generators that convert heat from decaying plutonium into electricity. After nearly five decades in space, engineers have had to progressively power down heaters and instruments while ensuring that the spacecraft do not become too cold, which could jeopardize key systems, including fuel lines.
“The team remains focused on keeping both Voyagers going for as long as possible,” Badaruddin added.
The urgency of the shutdown increased after Voyager 1 experienced an unexpected drop in power during a routine roll maneuver on February 27. Engineers were concerned that any further decline could activate the spacecraft’s undervoltage fault protection system, designed to automatically shut down components to safeguard the probe. Recovering from such a fault can be a lengthy process and carries additional risks, prompting the team to act preemptively.
The Voyager probes remain the only spacecraft positioned far enough from Earth to collect data on detecting pressure fronts and regions of varying particle density in the space beyond our heliosphere, according to Nasa.
“Engineers are confident that shutting down the LECP will give Voyager 1 about a year of breathing room,” a Nasa press release stated. “They are using the time to finalize a more ambitious energy-saving fix for both Voyagers they call ‘the Big Bang,’ which is designed to further extend Voyager operations.”
The “Big Bang” initiative aims to swap out a group of powered devices all at once, turning off some systems while replacing them with lower-power alternatives. This strategy is intended to keep the spacecraft warm enough to continue gathering scientific data.
The decision to deactivate the LECP was not made hastily. Nasa indicated that mission science and engineering teams had previously agreed on the order in which spacecraft systems would be shut down as power availability decreased. Out of the 10 original instrument sets carried by the twin probes, seven have now been powered down. Voyager 2’s LECP instrument was shut down in March 2025.
Given Voyager 1’s current distance of over 15 billion miles from Earth, commands take approximately 23 hours to reach the spacecraft. The shutdown sequence itself requires more than three hours to complete. However, one component of the LECP system — a small motor that rotates the sensor to scan in all directions — will remain powered, as it consumes only about half a watt. Engineers hope this will allow for the possibility of restarting the instrument in the future if more power becomes available.
As the Voyager missions continue, the team remains committed to maximizing the operational life of these pioneering spacecraft, which have provided invaluable insights into the outer reaches of our solar system and beyond, according to Nasa.