NASA has switched off one of the last working science instruments aboard Voyager 1 to keep the probe alive. Engineers at the Jet Propulsion Laboratory deactivated the low-energy charged particles instrument, known as LECP, on April 17, 2026, to preserve the limited electrical power still available to the spacecraft, which is now more than 25 billion kilometers from Earth.
Voyager 1 was launched in September 1977 to study the outer planets of the solar system, planets that until then had been observed only through telescopes. Its planetary mission was completed decades ago, after which the probe continued its journey through the interstellar medium. It left the heliosphere in August 2012 and is now the most distant human-made object in space, still transmitting data almost 50 years after its launch. The spacecraft currently sits roughly 25,394 million kilometers from our planet.
At that distance, neither Earth nor the Sun can supply enough energy for the probe, so it relies on radioisotope thermoelectric generators, sometimes described as nuclear batteries, which convert heat from the decay of plutonium-238 into electricity. The output of these generators drops by about 4 watts each year, leaving the probe with less power and a steadily shrinking margin for maneuvers. In February 2026, a routine maneuver caused a sudden and unexpected voltage drop that came close to ending the mission, the most distant human-made spacecraft's activity coming within a whisker of being cut off.
Because of this decline, mission teams have been shutting down instruments one after another for several years, following a load-reduction plan set by the scientists. The LECP was next on that list. With it gone, Voyager 1 has only two active science instruments left: the magnetometer and the plasma wave instrument. Both are expected to keep taking measurements for about one more year, thanks to the sacrifice of the LECP.
To keep the probe running until it reaches 50 years of service, the team has prepared a last-resort operation nicknamed "The Big Bang." It would reconfigure the spacecraft's entire energy management, modifying its thermal control and seeking alternatives that consume less power. The approach was previously tested on Voyager 2. If the reconfiguration succeeds, engineers hope to temporarily reactivate some of the shut-down instruments, which would produce the most distant data ever collected by humanity, a scientific gold mine far beyond 25,000 million kilometers from Earth.
The probe is also approaching a symbolic threshold that was unthinkable when it was launched almost 50 years ago. Within a few months, radio signals from Voyager 1 will take an entire day to reach Earth, placing the spacecraft one light-day from the planet. Keeping the mission alive long enough to reach that milestone, and to reach its 50th year of service, is now the central goal of the team.