In May, NASA scientists said the Voyager 1 spacecraft was returning inaccurate data from its altitude control system. The mysterious bug is still ongoing, according to the mission’s engineering team. To find a solution, engineers are now digging through manuals that are decades old.
Voyager 1, along with its twin Voyager 2, was launched in 1977 with a projected lifespan of five years to study Jupiter, Saturn, Uranus, Neptune and their respective moons up close.
After nearly 45 years in space, both spacecraft are still functioning. In 2012, Voyager 1 became the first-ever man-made object to venture beyond the limit of our Sun’s influence known as the heliopause and into interstellar space. It’s now about 14.5 billion miles from Earth, sending back data from outside the solar system.
“Nobody thought it would take this long,” Suzanne Dodd, project manager for the Voyager mission at NASA’s Jet Propulsion Laboratory, told Insider, adding, “And here we are.”
Voyager 1 was designed and built in the early 1970s, complicating efforts to fix the spacecraft’s problems.
Although current Voyager engineers have some documentation — or command media, the technical term for the paperwork detailing the spacecraft’s design and procedures — from those early mission days, other important documents may have been lost or misplaced.
According to Dodd, thousands of engineers worked on the project during the first 12 years of the Voyager mission. “When they retired in the ’70s and ’80s, there wasn’t much of a push to have a library of project documents. People took their boxes home to their garage,” Dodd added. On modern missions, NASA maintains more robust documentary records.
There are some boxes of documents and schematics kept outside of the Jet Propulsion Laboratory, and Dodd and the other Voyager personnel can request access to these records. Still, it can be a challenge. “To get that information, you need to find out who’s working on the project in that space,” Dodd said.
For Voyager 1’s latest bug, mission engineers had to specifically look for boxes under the names of engineers who helped design the altitude control system. “It’s a time-consuming process,” Dodd said.
The spacecraft’s altitude control system, which sends telemetry data back to NASA, indicates Voyager 1’s orientation in space and keeps the spacecraft’s high-gain antenna pointed at Earth so it can send data home.
“Telemetry data is basically a health status of the system,” Dodd said. But the telemetry reads that the spacecraft’s handlers get from the system are garbled, Dodd said, meaning they don’t know if the altitude control system is working properly.
So far, Voyager engineers haven’t been able to find a cause for the failure, mainly because they couldn’t reset the system, Dodd said. Dodd and her team believe it’s due to an aging part. “Not everything works forever, not even in space,” she said.
Voyager’s mishap can also be influenced by her position in interstellar space. According to Dodd, the spacecraft’s data suggests that there are high-energy charged particles in interstellar space. “It’s unlikely that one would hit the spacecraft, but if it did, it could do more damage to the electronics,” Dodd said, adding, “We can’t pinpoint that as the source of the anomaly, but it could be a factor.” .”
Despite the spacecraft’s orientation problems, it’s still receiving and executing commands from Earth and its antenna is still pointed at us. “We didn’t see any degradation in signal strength,” Dodd said.
As part of an ongoing power management effort that has intensified in recent years, engineers have shut down non-technical systems aboard Voyager spacecraft, such as heaters for scientific instruments, in hopes of keeping them running through 2030 .
From the discovery of unknown moons and rings to the first direct evidence of the heliopause, the Voyager mission has helped scientists understand the cosmos. “We want the mission to last as long as possible because the scientific data is so valuable,” Dodd said.
“It’s really remarkable that both spacecraft are still working and working well — small glitches, but they’re working very well and still sending back this valuable data,” Dodd said, adding, “They’re still talking to us.”