What is Happening with Voyager 1?
Traveling in Space Since 1977
Photograph: NASA/HULTON ARCHIVE/GETTY IMAGES
NASA’s Voyager 1 is the most distant human-made object in space at about 24 billion kilometers (15 billion miles) away from Earth. Since its launch on September 5th, 1977, Voyager 1 has been traveling at roughly 17 kilometers per second (10.5 miles per second) through the solar system and - since 2012 - interstellar space. For over 46 years, the spacecraft has supplied us with wonderful views of the more distant planets and discoveries such as the two new moons of Jupiter (back in 1979) and an additional ring surrounding Saturn (in 1980). Its twin, Voyager 2, which was actually launched 16 days before Voyager 1, took a more leisurely route through the solar system and has now traveled more than 20 billion kilometers (12 billion miles) from Earth. It was overtaken by its sister Voyager 1 back in 1980, when Voyager 1 picked up speed during its encounter with Saturn.
The two Voyager probes were initially designed to last five years with the primary mission to study and explore Jupiter, Saturn, Uranus and Neptune, a goal the longest-operating spacecraft in history achieved decades ago.
Currenty there are no other operational spacecraft exploring interstellar space. However, NASA’s New Horizons probe, which was launched in 2006 and flew past Pluto in 2015, is on track to reach interstellar space in the 2040s.
Computer Glitch in November 2023
The Voyager probes' unexpected lengthy journeys have not been without challenges. In December 2023 NASA shared some troubling news about Voyager 1 following a computer glitch that occurred on November 14th, 2023 and that has been causing a communication breakdown between the spacecraft and its mission team on Earth.
Voyager 1 has three onboard computers, including a flight data system (FDS) that collects information from the spacecraft’s science instruments and bundles it with engineering data about the spacecraft’s health into a single data package in a binary code: a series of ones and zeros. The FDS then sends that data on to the Telemetry Modulation Unit (TMU), which beams it back to Earth through Voyager 1’s dish antenna.
Enlarge / A scanned 1970s-era photo of the Flight Data Subsystem computer aboard NASA's Voyager spacecraft.
Since November of last year, Voyager 1 has been sending back a random and repeating series of ones and zeros instead of the flight data system messages that should have been reporting its scientific observations. According to NASA, Voyager 1’s flight data system appears to be stuck on auto-repeat since then and while the spacecraft can apparently still receive and carry out commands transmitted from its mission team on Earth, the computer glitch means that no science or engineering data from Voyager 1 is being returned to Earth. The only signal the engineers have received since November 2023 is a carrier tone which tells them that the spacecraft is still alive. There is no indication of any other other major problems.
Over three months after the problem started, it is unfortunately still happening, despite some of the best engineers in the world working on the issue. The complication lies primarily in the spacecraft’s old age and long distance from Earth. Voyager 1 is so far away that it takes 22.5 hours for commands sent from Earth to reach the spacecraft and another 22.5 hours to receive a response in order to know whether the command worked or not. Additionally, because the probe was built in the 1970s, its onboard technology is no longer state-of-the-art. The people who built Voyager 1 are unfortunately no longer alive and the spacecraft’s documentation is contained in old paper documents from decades ago and does not necessarily contain any guidance for fixing the current problem.
Time to Say Goodbye?
Voyager 1 has had computer glitches before. The last time it experienced a similar problem with the flight data system was way back in 1981 and the current issue does not appear to be connected to other computer problems the spacecraft has experienced in recent years.
Voyager’s mission support team in Southern California is still working hard on solving the glitch and saving the spacecraft. However, Voyager’s Project Manager Suzanne Dodd explained in an interview that “it would be the biggest miracle if we get it back.” Therefore, even though the Voyager scientists remain committed and somewhat hopeful, they are also preparing for the worst: A goodbye.
If the mission team is unable to reestablish contact with Voyager 1, NASA will still have at least one probe in interstellar space. Voyager 2, the twin spacecraft, crossed the barrier in 2018 and has for the most part maintained contact with Earth since.
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