NASA Shuts Down Another Science Instrument to Extend Voyager 1’s Lifespan
NASA’s Jet Propulsion Laboratory engineering team has instructed the Voyager 1 deep space probe to shut down its Low-Energy Charged Particle experiment (LECP) to extend the lifespan of the first interstellar probe as its power dwindles.
The LECP has been operating almost continuously since Voyager 1’s launch in 1977, for nearly 49 years, collecting a wealth of scientific data by observing low-energy charged particles – including ions, electrons, and cosmic rays – from the solar system and the galaxy. This instrument has helped scientists map the structure of the interstellar medium beyond the heliosphere and detect the distribution of different particle density and pressure fronts in interstellar space. Currently, only the Voyager twin probes are far enough from Earth to provide relevant information in this unique spatial environment.
Like Voyager 2, Voyager 1 is powered by a radioisotope thermoelectric generator, which generates electricity through the heat released by plutonium decay. However, both probes lose approximately 4 watts of usable power each year. After nearly half a century of flight, power redundancy is reaching its limit, and the mission team has had to save energy by sequentially shutting down heaters and some scientific instruments while ensuring the probe does not freeze and its fuel lines become blocked.
On February 27th of this year, Voyager 1 performed a planned attitude roll maneuver, but experienced an unexpected drop in power during the process. Engineers realized that if the power dropped further, it could trigger the spacecraft’s undervoltage fault protection system, automatically shutting down some components to protect itself. This would then require the ground team to perform a complex and time-consuming recovery operation, which also carries risks. Therefore, the team chose to be proactive and take measures in advance.
“No one wants to turn off a science instrument, but under the current conditions, this is the best choice we can make,” said Karim Badaruddin, Voyager Project Manager at the Jet Propulsion Laboratory. He pointed out that Voyager 1 still has two scientific instruments operating normally – one to “listen” to plasma fluctuations and another to measure magnetic fields – and these devices continue to send back data from deep space regions that humans have never visited. The team’s goal is to keep both Voyager probes running for as long as possible.
In fact, the decision to shut down LECP was not made on a whim, but was already written into the mission’s “long-term planning.” Several years ago, the science and engineering teams reached a consensus on the order in which equipment would be gradually shut down in the future, in order to extend the scientific value of the mission as much as possible given the continuous decline in power. Each probe initially carried 10 sets of identical scientific instruments, of which 7 have already been shut down, and now it’s the turn of the LECP on Voyager 1 to be shut down, while the equivalent instrument on Voyager 2 was shut down in March 2025.
Since Voyager 1 is currently over 15 billion miles (approximately 25 billion kilometers) from Earth, it takes about 23 hours for instructions sent from the ground to reach the probe, and the shutdown process itself takes another approximately 3 hours and 15 minutes. It is worth noting that a small motor in the LECP system used to rotate the sensor to scan the entire sky will continue to operate, as it only consumes about 0.5 watts of power. Keeping this component running will help preserve the possibility of re-enabling the instrument if a little more power can be “squeezed out” in the future.
Engineers estimate that shutting down LECP will buy Voyager 1 about a year of “breathing room.” The team plans to use this time to develop and implement a more ambitious energy-saving plan for the two probes, internally called “Big Bang.” The idea behind this approach is to adjust an entire set of electrical equipment at once, shutting down some devices and replacing some functions with low-power components, while maintaining the probe’s internal temperature and continuing to support scientific observations.
According to the plan, the “Big Bang” scheme will first be implemented on Voyager 2, which has slightly more power and is closer to Earth, as a relatively safe test subject. Relevant tests are currently scheduled for May to June 2026. If all goes well, the team will attempt the same operation on Voyager 1 as early as July. If everything works as expected, there will still be hope of restarting the LECP on Voyager 1 in the future.