By Since late 2023, scientists have been seeking to get the Voyager spacecraft back online.
Image: NASA/JPL-Caltech
On Dec. 12, 2023, NASA shared worrying information about Voyager 1, the first probe to walk away from our solar system‘s gravitational party and enter the isolation of interstellar space. Surrounded by darkness, Voyager 1 seems to be glitching.
It has been present there for more than 45 years, contributing a lot in giving information like the discovery of two new moons of Jupiter, another incredible ring of Saturn and the warm feeling that comes from knowing pieces of our lives will drift across the cosmos even after we’re gone. (See: The Golden Record.) But now, Voyager 1‘s fate seems to be problematic.
As of Feb. 6, NASA said the team is working on bringing the spacecraft back to proper health. “Engineers are still working to resolve the defect on Voyager 1,” NASA’s Jet Propulsion Laboratory said in a post on X (formerly Twitter). “We can talk to the spacecraft, and it can hear us, but it’s a slow process given the spacecraft’s incredible distance from Earth.”
So, on the bright side, even though Voyager 1 sits so utterly far away from us, ground control can actually communicate with it. In fact, last year, scientists beamed some software updates to the spacecraft as well as its counterpart, Voyager 2, from billions of miles away. Though on the dimmer side, due to that distance, a single back-and-forth communication between Voyager 1 and anyone on Earth takes a total of 45 hours. If NASA finds a solution, it won’t be for some time.
The defect that engineers realized, has to do with one of Voyager 1’s onboard computers known as the Flight Data System, or FDS. (The backup FDS stopped working in 1981.)
“The FDS is not interacting properly with one of the probe’s subsystems, known as the telemetry modulation unit (TMU),” NASA said in a blog post. “As a result, no science or engineering data is being sent back to Earth.” This is of course despite the fact that ground control can indeed send data to Voyager 1, which, at the time of writing this article, sits about 162 AU’s from our planet. One AU is equal to the distance between the Earth and the sun, or 149,597,870.7 kilometers (92,955,807.3 miles).
From Scratch
Voyager 1’s FDS dilemma was first observed last year, after the probe’s TMU stopped sending back clear data and started performing glitch.
As NASA described in the blog post, one of the FDS’ core jobs is to gather information about the spacecraft itself, in terms of its health and general status. “It then combines that information into a single data ‘package’ to be sent back to Earth by the TMU,” the post says. “The data is in different types like of ones and zeros, or binary code.”
However, the TMU seemed to be shuffling back a non-intelligible version of binary code recently. Or, as the team puts it, it seems like the system is “snuck.” Yes, the engineers attempted turning it off and on again.
But that didn’t work.
The cover of the Golden Record, copies of which were sent on the NASA’s Voyager 1 and Voyager 2 probes in 1977. (Image credit: NASA)
Then, in early February, Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory, told Ars Technica that the team might have concentrated what’s going on with the FDS at last. The theory is that the issue is occurring somewhere with the FDS’ memory; there might be a computer bit that got corrupted. Unfortunately, though, because the FDS and TMU work together to transmit data about the spacecraft’s health and general status, engineers are facing difficulties figuring out where exactly the possible corruption may exist. The messenger is the one that needs a messenger.
They do know, however, that the spacecraft must be alive because they are receiving what’s known as a “carrier tone.” Carrier tone wavelengths don’t carry data, but they are signals nonetheless, akin to a heartbeat. It’s also worth taking in account that Voyager 1 has been facing problems before, such as in 2022 when the probe’s “attitude articulation and control system” exhibited some blips that were ultimately patched up. Something similar happened to Voyager 2 during the summer of 2023, when Voyager 1’s twin felt some antenna problems before coming right back online again.
Still, Dodd says this situation has been the most complicating since she began working on the historic Voyager mission.
