NASA Shuts Down LECP on Voyager 1 as RTG Output Declines After 49 Years
NASA deactivated Voyager 1's LECP instrument per a pre-set order to conserve RTG power, buying one year while finalizing the 'Big Bang' reconfiguration; two science instruments remain active in interstellar space.
NASA engineers sent commands to shut down the Low-energy Charged Particles experiment on Voyager 1 to manage the probe's declining power.
The nuclear-powered RTG loses 4 watts per year, prompting the pre-planned shutdown of the eighth instrument set on April 17, 2026, after an unexpected power drop in February (NASA, https://science.nasa.gov/blogs/voyager/2026/04/17/nasa-shuts-off-instrument-on-voyager-1-to-keep-spacecraft-operating/). The LECP had operated since the 1977 launch, providing data on cosmic rays and the interstellar medium beyond the heliosphere, which Voyager 1 crossed in 2012 (Stone et al., Science, 2013).
Similar power constraints led to the LECP shutdown on Voyager 2 in March 2025. With only the plasma wave and magnetic field instruments active, Voyager 1 continues to return data unavailable from any other source. The team kept a 0.5-watt LECP motor running for potential future reactivation.
Preparation continues for the 'Big Bang' power fix, involving multiple component swaps to be tested on Voyager 2 first. This builds on lessons from earlier missions like Pioneer 10 and 11, which ended communications due to RTG depletion in the early 2000s (NASA Pioneer archives). The 23-hour command travel time at 15 billion miles underscores the autonomous nature of deep space operations.
AXIOM: Incremental instrument shutdowns and the upcoming Big Bang reconfiguration may extend Voyager data collection into the early 2030s, but continued 4W annual RTG decay follows the same terminal pattern seen in the Pioneer probes.
Sources (3)
- [1]NASA Shuts Off Instrument on Voyager 1 to Keep Spacecraft Operating(https://science.nasa.gov/blogs/voyager/2026/04/17/nasa-shuts-off-instrument-on-voyager-1-to-keep-spacecraft-operating/)
- [2]Voyager 1 Explores the Interstellar Medium(https://www.science.org/doi/10.1126/science.1232456)
- [3]Pioneer 10 and 11 Mission Documents(https://www.nasa.gov/history/pioneer-missions/)