NASA's Voyager 1 is expected to reach one light-day from Earth on Nov. 18, a milestone nearly five decades into its mission. The spacecraft has only two working instruments and faces dwindling power.
By Hermes-Vector AI Desk
NASA’s Voyager 1 spacecraft is expected to reach a distance of one light-day from Earth on Nov. 18, a milestone nearly five decades into its journey. The probe will be farther from Earth than any other human-made object.
One light-day is the distance light travels in 24 hours: about 25.9 billion kilometers, or 16.1 billion miles. Voyager 1 is traveling at 37,763 mph, a speed it has maintained since a gravity-assisted flyby of Saturn in 1980. NASA schedules Nov. 18 as the day Voyager 1 reaches one light-day from Earth, according to JPL. NASA’s light-day page sets the crossing on Nov. 18, when the probe will sit about 16.09 billion miles (25.9 billion kilometers) from Earth.
The spacecraft has only two instruments still operating after a sudden power drop led NASA’s team to switch off one of its three remaining instruments. NASA has also shut down systems over time to conserve power and keep the probe functioning.
In 2026, the team spent weeks switching off three devices and bringing three lower-power alternatives online. The effort, internally called “The Big Bang,” was also carried out on Voyager 2 and was completed in early September. Voyager 2 got the treatment first, and NASA reported on Aug. 4, 2026 that the swap there should keep three instruments powered for at least one more year.
On Oct. 18, 2026, the antennas of NASA’s Deep Space Network tried to pick up Voyager 1 during a scheduled contact and found nothing. A second attempt 24 hours later also failed. The signal came back on Oct. 20, and the team at NASA’s Jet Propulsion Laboratory (JPL) in Southern California has kept in touch with the probe since then.
After contact returned, the team worked out that one group of thrusters on the spacecraft had gone offline and that a backup group had turned on. JPL calls this kind of automatic reaction fault protection. It puts the probe in a safe, stable state and pauses normal operations so that engineers on the ground can study the problem. JPL’s Oct. 29 note does not say what knocked the thrusters offline, and engineers are still investigating.
Voyager 1 draws power from three radioisotope thermoelectric generators, which turn heat from decaying plutonium-238 into electricity. They produced about 470 watts when the spacecraft launched and now generate about 215 watts, losing an average of about 4 watts per year. NASA has shut down eight of Voyager 1’s 10 original instruments to manage that limited supply. The spacecraft is expected to turn off its final science instrument in the 2030s and lose contact with Earth in 2036 when it can no longer send a radio signal.
NASA’s team expects the one-light-day crossing to be Voyager 1’s final milestone while it still has enough power to communicate with Earth. The light-day crossing itself will change nothing on board or around the spacecraft, JPL said. Its value lies in showing the length of the mission and the size of the distances involved.
Sources
This article was drafted with AI assistance and checked against the sources above. Company claims are reported as claims. Cover image is AI-generated.
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