On April 17, 2026, NASA’s Jet Propulsion Laboratory sent a command across 15 billion miles of space to shut down one of Voyager 1’s last working science instruments. About 23 hours later, the signal arrived. Three hours and one minute after that, the Low-Energy Charged Particles experiment went dark for good.
The shutdown leaves Voyager 1 with just two functioning science instruments, its magnetometer and plasma wave subsystem, as the 48-year-old spacecraft’s nuclear power source continues its slow, irreversible decline. But the move is not just about saving watts. It is part of a broader reconfiguration effort that the mission team has been calling the “Big Bang” fix, a sweeping set of changes aimed at keeping the probe transmitting well into the next decade.
Why the LECP had to go
The LECP had been one of Voyager 1’s original instruments since its 1977 launch, measuring the energy and composition of charged particles from the sun, the galaxy, and the planets the spacecraft flew past decades ago. In interstellar space, it tracked how low-energy ions and electrons behave at the boundary where the sun’s influence gives way to the wider galaxy.
But the instrument was expensive to run. Its stepper motor, which rotated a sensor platform to scan in different directions, drew what has been described as a 15.7-watt pulse every 192 seconds from a capacitor bank, though those specific figures may reflect mission-team estimates rather than values stated in the linked source. On a spacecraft where every fraction of a watt now matters, those periodic power spikes made the LECP one of the most demanding systems still operating. JPL opted to keep a single 0.5-watt motor component powered on but shut down everything else.
A mission update from NASA confirmed the shutdown and described it as part of a deliberate power-conservation strategy that has been unfolding for more than a year.
A growing list of goodbyes
The LECP is not the first instrument to be sacrificed. Voyager 1’s Cosmic Ray Subsystem was turned off on February 25, 2025. Voyager 2’s LECP was scheduled to go offline on March 24, 2025, according to a NASA blog post that confirmed the plan. Voyager 2’s Plasma Science instrument was deactivated on September 26, 2024. Voyager 1’s own Plasma Science experiment had already been shut down years earlier due to degraded performance.
NASA’s current status page now lists only two active science instruments on Voyager 1. The magnetometer tracks the direction and strength of magnetic fields in interstellar space. The plasma wave subsystem detects electron density and low-frequency radio emissions. Together, they offer a narrow but scientifically valuable window into a region no other spacecraft has ever reached.
Both instruments owe their survival partly to a painstaking rescue effort in 2024. On November 14, 2023, a single faulty memory chip caused Voyager 1 to stop sending readable data entirely. Engineers at JPL spent months diagnosing the problem and eventually relocated corrupted code within the spacecraft’s memory, restoring science returns from across billions of miles of empty space.
What the ‘Big Bang’ fix involves
JPL engineers have been preparing a broader systems reconfiguration that goes beyond simply turning off instruments one by one. Referred to internally as the “Big Bang” fix, the effort is expected to involve changes to how the spacecraft allocates its shrinking power budget across science instruments, heaters, and communications hardware.
Publicly available NASA documents have not yet laid out the full scope, timeline, or technical specifics of the reconfiguration. Whether it includes additional software patches to the flight data subsystem, further heater shutdowns, or a rebalancing of power among non-science systems remains unconfirmed in primary sources reviewed for this report. What is clear is that the LECP shutdown was a prerequisite, freeing up power headroom before the larger changes begin.
The exact power savings from the LECP shutdown are also difficult to pin down. Because the stepper motor consumed energy in brief pulses rather than drawing a constant load, the net gain depends on how the spacecraft’s power-management system redistributes that capacity. Voyager 1’s radioisotope thermoelectric generators lose an estimated 4 watts per year as their plutonium-238 fuel decays, an approximation that smooths over uncertainties in thermoelectric performance. No updated RTG output figure for 2026 has been published.
What science is lost
Without the LECP, researchers lose their only direct measurement of low-energy particle populations in the local interstellar medium from Voyager 1’s vantage point. The instrument captured data on ions and electrons at energies below what the now-deactivated Cosmic Ray Subsystem was designed to detect. That information helped scientists understand how the solar wind’s remnants mix and interact with material from other stars.
Whether the magnetometer and plasma wave subsystem can partially compensate for that gap has not been addressed in official NASA statements. The two surviving instruments measure different physical properties, magnetic fields and electron densities, so the overlap with LECP’s particle-energy measurements is limited at best.
In a 2025 blog post, NASA projected that sequential shutdowns could keep at least one science instrument running into the 2030s. That estimate assumes the RTGs degrade at a predictable rate and that no further hardware failures strike a spacecraft built during the Ford administration. Neither assumption is guaranteed.
Still exploring, still transmitting
NASA has stressed that the LECP shutdown does not signal a loss of contact or control. Voyager 1 remains responsive to commands, and its radio transmitter continues to relay engineering and science data through the Deep Space Network. The spacecraft is currently more than 15 billion miles from Earth, a distance so vast that a signal traveling at the speed of light takes roughly 23 hours to make the one-way trip.
Each instrument shutdown undeniably narrows what Voyager 1 can observe. But the record over nearly five decades shows a mission team that has repeatedly found ways to stretch hardware far beyond its intended lifespan, whether by relocating code around a dead memory chip or by carefully rationing watts from a fading nuclear battery.
The two instruments still running continue to return data from a place no human-made object has explored before. As JPL prepares the “Big Bang” reconfiguration, the goal is not just to keep Voyager 1 alive a little longer. It is to make sure that when the spacecraft finally does go silent, it has sent back every bit of science it possibly can.
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*This article was researched with the help of AI, with human editors creating the final content.
