WASHINGTON – The four instruments on NASA’s Voyager 1 spacecraft are returning science data for the first time since a computer failure last November, as scientists hope to keep the mission operational for another decade.
NASA’s Jet Propulsion Laboratory announced June 13 that the spacecraft’s four instruments, which measure plasma waves, magnetic fields and particles in interstellar space, have started returning data. Two of the instruments started immediately after commands were sent to the spacecraft on May 19, while the other two required what JPL called “some additional work” to resume operations.
The instruments had been offline since November 2023, when a computer glitch on board the spacecraft caused it to return garbled data. A “tiger team” of engineers traced the problem to a damaged memory chip in one of the spacecraft’s computers and rewrote the software to prevent that chip from being used. That effort restored communications with the spacecraft in April.
“The Tiger team was able to reprogram and move that code, first for the technical part of the data modes coming out of the spacecraft,” said Linda Spilker, Voyager project scientist, at an Outer Planets Analysis Group meeting on June 13, where she announced the instruments were working again. “We are now getting science data back from all four of Voyager 1’s science instruments.”
“This is the first flight software update for a spacecraft in interstellar space,” she added. “The last time we really did much with the flight software was before launch.” Voyager 1 launched in 1977.
Now that the spacecraft’s computer is working again, the main factor limiting the lifespan of Voyager 1 and its twin, Voyager 2, is declining power levels. Each spacecraft loses about four watts per year, a combination of the decay of their plutonium-238 power supplies and the degradation of the thermocouples that convert the heat from that decay into energy.
Controllers managed the dwindling power by turning off non-essential systems, including heaters that kept instruments and other components warm. “What happens is the spacecraft gets cold, so we have an energy problem as well as a thermal problem,” Spilker said.
She said the mission will have to turn off the instruments itself at some point, but hoped the spacecraft might be able to continue operating into the next decade.
“With any luck, it may be possible to continue data collection by the Voyager spacecraft into the 2030s,” she said. If Voyager 1 makes it in 2035, it will be 200 astronomical units, or about 30 billion kilometers, from the sun. It is currently over 15 billion miles from the sun.
“Right now our focus is on getting to 2027,” she said. “That will be fiftye anniversary of the launch of both Voyager spacecraft.”
The announcement that Voyager 1’s instruments were once again returning data came two days after JPL announced the death of Ed Stone, who served as Voyager project scientist from the mission’s inception in 1972 until 2022, when he retired and was replaced by Spilker . Stone, a professor of physics at Caltech, also served as director of Caltech from 1991 to 2001.
“Ed Stone often said during the planetary flyby phase that we had a rare opportunity with the alignment of the planets and we seized it,” she said of the “Grand Tour” trajectory that allowed the Voyager spacecraft to fly by Jupiter , Saturn to fly, Uranus and Neptune. “I would add that both Voyagers still have rare opportunities, and Ed will continue to take advantage of them.”