After nearly 49 years of operation, NASA has turned off the LECP instrument on Voyager 1 to conserve power. The spacecraft, more than 25 billion kilometers from Earth, will continue to collect data using two scientific instruments that remain active.
On April 17, engineers at NASA's Jet Propulsion Laboratory (JPL) sent commands to shut down an instrument on Voyager 1 called the LECP (Low Energy Charged Particle Experiment). The nuclear-powered spacecraft regularly loses power, and shutting down this instrument is the most effective means of extending the mission of the first man-made object to reach interstellar space.
The device went silent after 49 years
LECP has operated with very few interruptions since Voyager 1 was launched in 1977. It measures low-energy charged particles such as ions, electrons, and cosmic rays from our solar system and the galaxy as a whole. Over the years, it has provided vital data on the interstellar medium, including the detection of pressure waves and changes in particle density beyond the heliosphere. Voyager 1 and 2 are the only spacecraft far enough away to collect this type of data.
Loss of power after decades in space
Like its twin, Voyager 2, Voyager 1 relies on a radioisotope thermoelectric generator, which converts heat from decaying plutonium into electricity. Each spacecraft loses about four watts of power each year. After nearly five decades in space, the available energy becomes very limited. Engineers must carefully reduce electricity use by turning off heaters and appliances while keeping the spacecraft warm enough to prevent fuel lines from freezing.
During a planned roll maneuver on February 27, Voyager 1 experienced an unexpected power outage. Engineers realized that any further drop in power could trigger the undervoltage protection system. This safety system would automatically shut down components to protect the spacecraft, requiring a complex recovery operation that carried additional risks.
The team chose to act before this scenario occurred.
"Nobody likes to turn off a science instrument, but it's the best option," said Karim Badrudin, Voyager mission manager at JPL. "Voyager 1 still has two science instruments that are operational, one that listens for plasma waves and one that measures magnetic fields. They are still operating well and sending back data from a region of space that no human-made spacecraft has ever explored. The team remains focused on keeping both Voyager spacecraft operational for as long as possible."
Long-term device shutdown plan
The decision to shut down LECP was in accordance with a plan created years ago. Scientists and engineers worked together to determine the order in which systems would be shut down, with the goal of preserving as much scientific capability as possible. Each Voyager spacecraft originally had ten instrument systems, and seven had already been shut down. On Voyager 1, LECP was next in line. The corresponding instrument on Voyager 2 was shut down in March 2025.
Voyager 1 is now more than 25 billion kilometers from Earth, so communication takes a significant amount of time. Commands reach the spacecraft after about 23 hours, and once received, the shutdown process takes around three and a quarter hours.
A small portion of the LECP will remain active. A motor that rotates the sensor to scan in all directions will continue to run because it consumes very little power (0.5 watts). Leaving this component running preserves the ability to restart the device if more power becomes available.
Facts in brief
Why did NASA turn off the LECP instrument on Voyager 1?
To save power and extend mission life, after a sustained decrease in available power.
What instruments are still operating on Voyager 1?
Two scientific instruments remain active: one to measure plasma waves and one to measure magnetic fields.
How far is Voyager 1 from Earth?
Voyager 1 is currently more than 25 billion kilometers from Earth, so a command from Earth reaches it after about 23 hours.
