Close to half a century after launching into space, NASA’s Voyager 1 spacecraft is about to reach a significant milestone—that is, if engineers can keep its systems functional until that time.
As the iconic spacecraft continues its journey beyond our Solar System, later this month, on November 18, the probe is expected to reach a distance of approximately 16.09 billion miles (25.89 billion kilometers) from Earth.
That’s significant because it’s the equivalent of one light-day—the distance light travels in 24 hours. While the spacecraft has already traveled further than any human-built object, NASA engineers are nonetheless working to keep the spacecraft alive amid several recent technological hurdles it has faced.
However, in the weeks leading up to the new milestone, NASA’s iconic spacecraft has experienced several problems, including an “unexpected” temporary loss of communication with the spacecraft last month.
Adding to the complication is that once it reaches this next milestone distance in its journey into the cosmos, it will take precisely 24 hours for engineers on Earth to communicate with the ancient spacecraft via NASA’s Deep Space Network.
“If you want to say ‘hello’ to Voyager, you send your message and then you go home and you wait two days before you finally get a response,” said Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory (JPL).
New Milestones for an Aging Spacecraft
In recent months, NASA engineers were successful in completing an ambitious operation they nicknamed the “Big Bang,” which aimed to save power on Voyager 1 as some of its remaining systems continue to operate on exceedingly low power stores.
By replacing three of the probe’s most energy-consuming devices with lower power alternatives, Voyager 1’s remaining scientific instruments will now potentially be able to help it prevent another instrument shutdown that otherwise might have been necessary by summer 2027.
Both Voyager probes operate using radioisotope thermoelectric generators, which provide power through the conversion of heat from decaying plutonium into electricity. However, each year an overall power decline of approximately four watts occurs, which forces engineers to carefully manage the spacecraft’s dwindling energy reserves.
Lost Contact
In another recent incident, Voyager unexpectedly lost contact during a series of scheduled communication attempts between October 18 and 19. Fortunately, communication was reestablished after the nearly 48-hour interruption.
Following that event, NASA engineers determined that one of the spacecraft’s group of thrusters had apparently gone offline, causing the spacecraft to automatically engage its backup thrusters. Presently, NASA is still investigating the cause of the incident.
“This is the first time we’ve seen the spacecraft do something like this, but we are also at a point in the mission where we have to expect the unexpected,” said Voyager mission manager Kareem Badaruddin.
An Iconic Journey
Voyager 1 was launched in 1977, and since that time has continued its epic journey, now making its way through interstellar space at a speed of roughly 38,000 miles per hour.
On its way, the aging spacecraft continues to gather scientific data from a region in space no other spacecraft occupies, where it is beyond the protective heliosphere of our Sun.
While crossing the one-light-day threshold later this month will represent no physical changes for the ancient space probe, it is a milestone that marks the incredible longevity of NASA’s Voyager mission, as well as the immense distances that its farthest-distant human-built spacecraft has traveled during its historic space explorations.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.