NASA’s iconic Voyager 1 probe is back online after the spacecraft experienced another pause in communication last month.
In an update on November 26, the American space agency confirmed that the probe had resumed its regular operations following an unexpected shutdown of its primary radio (X-band) transmitter, opting instead to engage its comparatively weak S-band transmitter.
Voyager 1, currently located at an incredible 15.4 billion miles from Earth as it makes its way further into interstellar space, is at a great enough distance that it has become difficult for its mission controllers to retrieve information from the probe, including science data it continues to log and crucial details about its operational status.
NASA revealed last month that the probe’s X-band transmitter was successfully reactivated despite its distance from Earth, allowing the probe to resume data collection and transmission using its array of science instruments by mid-November.
Currently, mission engineers are working to restore Voyager 1 to its prior state of operation before the latest issues it experienced. These efforts included resetting Voyager 1’s system to synchronize its three computers.
The cause behind the shutdown of the probe’s X-band transmitter, reportedly resulting from the engagement of a protection system built into the decades-old space probe, was also determined.
“The X-band transmitter had been shut off by the spacecraft’s fault protection system when engineers activated a heater on the spacecraft,” wrote Tony Greicius in a status update on NASA’s Voyager blog.
In the past, this fault protection system would automatically shut down systems on Voyager 1 that were not crucial to its primary operations, thereby allowing the spacecraft to preserve power and distribute it more economically amid systems critical for its operation.
Greicius explained that the probe’s power-saving functions “turned off the X-band transmitter and turned on the S-band transmitter, which uses less power.”
Both Voyager 1 and its sibling, Voyager 2, have already shut down all capabilities that aren’t essential to their operations. Each of Voyager 1’s science instruments remains operational, although earlier this year, one of the science instruments on Voyager 2 was finally shut down.
While Voyager 1, currently the most distant human-built object anywhere in space, is officially back online for now, it could be only a matter of time before the spacecraft encounters further complications, primarily because it is losing something crucial for maintaining its operations: power.
Both Voyager probes continue to function despite each spacecraft’s significantly diminished power stores, which are driven by heat generated by decaying plutonium.
Each spacecraft converts this heat into electricity, but after more than four decades of about 4 watts of power loss per year, it remains unclear how much longer the Voyager spacecraft will be able to maintain their record-breaking operations.
There could still be signs of hope, however. Five years ago, anticipating the spacecraft’s critically low power generation would be incapable of continuing to power all its systems, the Voyager 1 team began shutting down systems that included heaters to help its science instruments function correctly.
Despite this, all Voyager 1’s currently active instruments remain in operation, even at temperatures far below their lowest tested values over four decades ago.
Still, there is some uncertainty about how much longer the Voyager probes will realistically be able to continue collecting useful science data. The remaining science instruments in operation on both spacecraft are currently being used to collect information NASA scientists are using to study phenomena that include plasmas, particles, and the behavior of magnetic fields the probes encounter from their locations in deep space.
Although NASA engineers continue to employ computer models to help them evaluate the power needed to maintain operations for the probe’s multiple systems, several factors, including the age of Voyager’s hardware and inconsistencies that occasionally arise in their function, make it difficult to determine whether the spacecraft’s life can be extended much further into the future.
The Voyager team is actively monitoring power levels on Voyager 1, which Greicius said are being “measured to fractions of a watt,” allowing engineers to better gauge how to maintain operations for as many systems onboard the craft as possible.
Even if the probes are approaching the end of their lifespan, each has been flying for more than 47 years and has already pushed the boundaries of our understanding with their record-breaking voyages into interstellar space.
As these elderly robotic explorers carry on their scientific pursuits, an increase in the frequency of technical issues their engineering teams will encounter can only be expected. Despite such challenges, the unprecedented achievement produced by each Voyager spacecraft already stands as a testament to their resilience.
With careful planning, NASA may have a few more years of valuable science data from two of its most iconic spacecraft to look forward to.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.