NASA Voyager 1 Spacecraft Turns Off LECP Instrument to Save Power

Among the most important space missions for humanity (also for their impact on society) are certainly the Voyager missions. The twin spacecraft launched in 1977 continue their journey into interstellar space, reaching places no mission launched by humanity has reached before! The onboard technology is now outdated, and NASA has gradually reduced the number of active scientific instruments to save energy. In recent hours, the U.S. space agency announced that the LECP instrument (Low-energy Charged Particles) of the NASA Voyager 1 spacecraft has been turned off, while additional measures will be taken in the future to extend its operational life as much as possible.

In just a few months, NASA Voyager 1 will be one light-day away from Earth, marking a new record for this spacecraft. With the plutonium-238-based radioisotope thermoelectric generator (RTG) running low and no other power sources available, every watt saved is crucial for reaching considerable distances and still collecting data from areas of space that won't be accessible for several years.

Currently, the NASA Voyager 1 spacecraft is about 25.4 billion km from Earth and is traveling at about 81,000 km/h, while Voyager 2 is 21.35 billion km from our planet, moving at just under 81,000 km/h (and 19 light-hours from Earth).

The NASA Voyager 1 Spacecraft and Onboard Instruments

As reminded by the JPL team, the LECP instrument has been operational, almost without interruption, since the launch of the spacecraft in the late 1970s, collecting useful information on low-energy charged particles (ions, electrons, and cosmic rays) coming from the Solar System and the Milky Way.

Thanks to data from NASA Voyager 1 (and its twin spacecraft), scientists have been able to study certain characteristics of the interstellar medium, showing that there are regions with different particle densities beyond the heliosphere. As mentioned earlier, currently, there are no other missions that can take measurements in these areas, and spacecraft that will venture so far might only be launched in a few years.

As they move so far from the Sun, solar panels would soon become insufficient, while it was not anticipated that these missions could last so long. The RTGs onboard the two Voyagers lose about 4 watts per year, making energy conservation not just important but crucial.

According to information released by NASA, at the end of February, the NASA Voyager 1 spacecraft experienced a sudden power drop that might have led to the automatic activation of the failure protection status. This situation is complicated to resolve, especially when it occurs on hardware from the late '70s at 23 light-hours away and under precarious conditions.

The control center therefore decided to deactivate LECP, leaving the magnetometer (MAG) and the Plasma Wave Subsystem (PWS) operational. On Voyager 2, the LECP instrument was already turned off in March 2025. The spacecraft still holds significant scientific value, and efforts will be made to keep it operational as long as possible. Interestingly, the team decided to keep a part of LECP active, which consumes 0.5 watts, to allow for reactivation of the instrument in the future if a way to extract additional energy from the RTG can be found. But that's not all.

JPL is already looking at the next steps. The energy-saving strategy has been named "Big Bang." Engineers are considering turning off several components simultaneously and activating others that consume less power. This strategy obviously carries risks for the spacecraft and will be implemented first on Voyager 2 (which has more available energy and is slightly closer to Earth). Tests will be conducted in May and June, and if all goes well, the procedure will also be sent to NASA Voyager 1 in July. After data acquisition, the actual savings will be checked, and if conditions permit, the LECP instrument could be reactivated.