I once sat with my dad while we googled how far different things in the solar system were from Earth. He was looking for exact numbers and obviously became more invested with each new number I called out. I was elated. The moon? An average of 238,855 miles (384,400 kilometers). The James Webb Space Telescope? Increase that to about a million miles (1,609,344 km). The sun? 93 million miles (149,668,992 km) away. Neptune? 2.8 billion miles (4.5 billion km) away. “Well, wait until you hear about Voyager 1,” I finally said, assuming he knew what was coming. He wasn’t.
“NASA’s interstellar spacecraft Voyager 1 isn’t really even in the solar system anymore,” I announced. “No, it’s more than 15 billion miles (24 billion km) away from us – and getting further away as we speak.” I can’t remember his answer, but I do remember a look of utter disbelief. There were immediate inquiries as to how this was even physically possible. There was puzzled laughter, different ways to say “wow” and most of all, there was an infectious sense of awe. And just like that, a new Voyager 1 fan was born.
It’s easy to see why Voyager 1 is among the most beloved robotic space explorers we have — and therefore easy to understand why so many people felt heartache a few months ago when Voyager 1 stopped talking to us.
Connected: After months of sending nonsense to NASA, Voyager 1 is finally making sense again
For reasons unknown at the time, this spacecraft began sending back gibberish in place of the neatly organized and data-rich 0s and 1s it had been providing since its launch in 1977. It was this classical computer language that allowed Voyager 1 to converse with its creators. , while earning the title of “farthest man-made object”. This is how the spacecraft delivered a vital insight that led to the discovery of new Jovian moons and, thanks to this kind of binary podcast, scientists amazingly identified a new ring on Saturn and created the first and only “family portrait” of the Solar System. This code is essentially critical to Voyager 1’s very existence.
Also, to make matters worse, the problem behind the problem turned out to be related to the ship’s flight data system, which is literally the system that relays information about the health of Voyager 1 so that scientists can correct any problems that arise. Problems like this. Also, because of the vast distance of the spacecraft from its operators on Earth, it takes about 22.5 hours for a transmission to reach the spacecraft, and then 22.5 hours to receive a transmission back. Alas, things didn’t look good for a while – about five months to be exact.
But then, on April 20, Voyager 1 finally called home with readable 0s and readable 1s.
“The team had gathered early in the morning over the weekend to see if the telemetry would come back,” Voyager flight team member Bob Rasmussen told Space.com. “It was nice to have everyone come together in one place like this to share the moment when we learned that our efforts had been successful.” We applauded both the intrepid spacecraft and the camaraderie that enabled its recovery.”
And then, on May 22, Voyager scientists made the welcome announcement that the spacecraft had successfully resumed returning science data from two of its four instruments, the Plasma Wave Subsystem and the Magnetometer Instrument. They are now working on bringing the other two, the Cosmic Ray Subsystem and the Low Energy Charged Particle Instrument, back online as well. Although there are technically six other instruments aboard Voyager, they have been out of service for some time.
The return
Rasmussen was actually a member of the Voyager crew in the 1970s, working on the project as a computer engineer before leaving for other missions, including Cassini, which launched the spacecraft that taught us almost everything we now know for Saturn. In 2022, however, he returned to Voyager due to a separate mission dilemma—and has remained with the team ever since.
“There are many of the original people who were there when Voyager launched, or even before, who were part of both the flight crew and the science team,” Linda Spilker, planetary scientist at NASA’s Jet Propulsion Laboratory , who also worked on the Voyager Mission, told Space.com on the TWiT Network’s This Week in Space podcast. “It’s a real tribute to Voyager — the longevity of not only the spacecraft, but the people on the team.”
To bring Voyager 1 back online, in rather cinematic fashion, the team came up with a complicated solution that had the FDS send a copy of its memory back to Earth. Within this memory read, the operators were able to discover the root of the problem—corrupted code spanning a single chip—which was then fixed through another (frankly, super interesting) code modification process. The day Voyager 1 finally spoke again, “you could have heard a pin drop in the room,” Spilker said. “It was very quiet. Everyone’s looking at the screen, waiting and watching.”
Of course, Spilker also brought some peanuts for the team to munch on—but not just any peanuts. Happy peanuts.
It’s a longstanding tradition at JPL to host a peanut feast before major mission events like launches, stages and, well, the possible resurrection of Voyager 1. It all started in the 1960s when the agency was trying to launch the Ranger 7 mission, which was designed to take pictures and collect data on the surface of the moon. Rangers 1 through 6 had failed, so Ranger 7 was a big deal. As such, the mission’s trajectory engineer, Dick Wallace, brought plenty of peanuts for the team to munch on and relax. Of course, Ranger 7 was a success and, as Wallace once said, “the rest is history.”
Voyager 1 needed these positive snacks.
“It had been five months since we had any information,” Spilker explained. And so, in this room of silence, save for the sounds of eating peanuts, the Voyager 1 operators sat in front of the screens of their respective systems and waited.
“All of a sudden it started filling in — the data,” Spilker said. Then the programmers staring at those screens in anticipation jumped out of their seats and started cheering: “I think they were the happiest people in the room and there was just a sense of joy that we have Voyager 1 back.”
Ultimately, Rasmussen says, the team was able to conclude that the damage likely occurred due to a combination of aging and radiation damage through which energetic particles in space bombarded the ship. That’s why he believes it wouldn’t be too surprising for a similar failure to occur in the future, given that Voyager 1 is still moving beyond the far reaches of our stellar neighborhood, just like its twin spacecraft, Voyager 2.
Of course, the spacecraft is still not fully repaired – but it’s great to know that things are finally looking up, especially with the recent news that some of its science instruments are back on their way. And at the very least, Rasmussen assures that nothing the team has learned so far is alarming. “We’re confident we have a good understanding of the problem,” he said, “and remain optimistic about getting everything back to normal — but we also expect this won’t be the last.”
In fact, as Rasmussen explains, Voyager 1 operators first became optimistic about the situation just after the root cause of the problem was established with certainty. He also emphasizes that the spirit of the team has never been weak. “We knew from circumstantial evidence that we had a spacecraft that was mostly healthy,” he said. “We didn’t think to say goodbye.”
“Rather,” he continued, “we wanted to move toward a resolution as quickly as possible so that other board issues that had been neglected for months could be addressed. We are now calmly moving towards this goal.”
The future of Voyager travel
It cannot be ignored that over the last few months there has been an atmosphere of anxiety and fear in the public space that Voyager 1 is slowly moving towards sending its final 0 and final 1. Headlines on the Internet, including one written by me, have clear, negative weight. I think it’s because even if Voyager 2 could technically carry the interstellar torch after Voyager 1, the prospect of losing Voyager 1 felt like the prospect of losing a piece of history.
“We crossed this boundary called the heliopause,” Spilker explained of the Voyagers. “Voyager 1 crossed that line in 2012; Voyager 2 crossed it in 2018 – and since then have been the first spacecraft ever to make direct measurements of the interstellar medium.” This medium basically refers to the material that fills the space between stars. In this case, it’s the space between other stars and our sun, which, although we don’t always think of it as one, is just another star in the universe. A drop in the cosmic ocean.
“JPL began construction of the two Voyager spacecraft in 1972,” Spilker explained. “For context, this was only three years after the first human walk on the moon – and the reason we started so early is because we had this rare alignment of the planets that happens once every 176 years.” It is this alignment that could promise the spacecraft control points throughout the solar system, including Jupiter, Saturn, Uranus and Neptune. These checkpoints were especially important to the Voyagers. Along with planet visits come gravity assists, and gravity assists can help fling things within the solar system — and, we now know, beyond.
As the first man-made object to leave the Solar System, a relic of America’s early space program, and a testament to how robust even decades-old technology can be, Voyager 1 has carved out the kind of legacy usually reserved for remarkable lost to the weather.
“Our scientists are eager to see what they missed,” Rasmussen noted. “Everyone on the team is self-motivated by their commitment to this unique and important project. That’s where the real pressure comes from.”
Yet, in terms of energy, the team’s approach is clinical and determined.
“No one was ever particularly excited or depressed,” he said. “We are confident that we can return to business as usual soon, but we also know that we are dealing with an aging spacecraft that is bound to have problems again in the future.” It’s just a fact of life on this mission, so it’s nothing to worry about.”
Still, I imagine it’s always a pleasure for the Voyager 1 engineers to remember that this robotic explorer is engaging curious minds around the world. (Including my dad’s mind now, thanks to me and Google.)
As Rasmussen says, “It’s wonderful to know how much the world appreciates this mission.”
Originally published on Space.com.
