Voyager 1 launched on September 5, 1977. It is, as of mid-2026, approximately 24.7 billion kilometers from Earth, traveling outward at about 17 kilometers per second. A radio signal from the spacecraft, traveling at the speed of light, takes roughly 22 hours and 50 minutes to reach Earth. A command sent from Earth to Voyager 1 takes the same time to arrive. A round-trip conversation is closer to two days than to a real-time exchange.
It is still talking.
The numbers
Voyager 1 is the most distant human-made object ever built. It crossed the heliopause, the boundary between the bubble of solar wind that fills our solar system and the interstellar medium beyond, on August 25, 2012. It is now flying through plasma that has never been disturbed by our Sun. The instruments that can still measure something are reporting back on the density and behavior of that plasma, on the magnetic field of interstellar space, and on the cosmic rays that arrive from elsewhere in the galaxy.
Voyager 2 launched 16 days earlier than its sibling, on August 20, 1977, but flew a slower trajectory through encounters with Uranus and Neptune. It crossed the heliopause on November 5, 2018. It is now about 20.7 billion kilometers from Earth. Both spacecraft are in interstellar space. Neither has yet reached the Oort Cloud, the diffuse cloud of icy bodies that scientists believe forms the true outer boundary of the solar system. Voyager 1 will not reach the inner edge of the Oort Cloud for roughly another three centuries.
The spacecraft are powered by Radioisotope Thermoelectric Generators (RTGs), which convert heat from the decay of plutonium-238 into electricity. The power output declines by about four watts every year. At launch, each Voyager produced around 470 watts. They now produce about 220 watts. Mission engineers turn off heaters and instruments to manage the power budget. There is a clear end-of-life for active science: somewhere in the early 2030s, the spacecraft will no longer have enough power to operate any instruments, and shortly after that they will lose the ability to communicate at all.
The 2024 memory rescue
In November 2023, Voyager 1 started sending garbled data. The science and engineering telemetry, normally readable, came back as a repeating pattern of ones and zeros. The spacecraft was clearly still working. It was responsive to commands. It just could not say anything coherent.
NASA’s Voyager team, based at the Jet Propulsion Laboratory in Pasadena, spent months diagnosing the problem. They worked from documentation that was, in some cases, written on paper in the 1970s by engineers who had since retired or died. They eventually traced the issue to a single corrupted chip in one of the spacecraft’s onboard computers. The chip stored a small portion of the code responsible for packaging telemetry into the format the radio system could send.
You cannot replace a chip on a probe 24 billion kilometers away. What you can do is patch around it. The engineers wrote new code that performed the same function as the broken chip, sliced it into pieces small enough to fit in unused regions of other onboard memory, and transmitted those pieces to the spacecraft. They told the operating system to call the patched code instead of the dead chip. In April 2024, after a 45-hour round-trip command cycle, Voyager 1 sent back its first coherent telemetry in five months.
The fix worked. The fix was performed on hardware that was launched the year the Apple II went on sale, by engineers in 2024, using paper documents from 1977, across a distance that no signal has ever traveled before for a remote software patch.
What is actually on the spacecraft
Each Voyager carries roughly 825 kilograms of hardware, including science instruments, an RTG, a 3.7-meter parabolic high-gain antenna, a propulsion system, and the famous Golden Record. The computers onboard are three pairs of redundant systems with a combined memory of about 70 kilobytes. A modern smartphone has roughly a million times more memory.
The Golden Record is a 12-inch gold-plated copper phonograph record. It contains greetings in 55 languages, music ranging from Bach to Chuck Berry to traditional songs from several cultures, natural sounds including wind and whales, and 116 encoded images of life on Earth. It is sealed in an aluminum case along with a stylus and instructions, in pictograms, for how to play it. The record is intended to last roughly a billion years in the interstellar medium.
The probability that any extraterrestrial civilization will ever recover it is, by any reasonable estimate, indistinguishable from zero. That is not the point of the record. The point of the record is that humans made it and sent it.
Where the Voyagers are going
Voyager 1 is heading in the general direction of the constellation Ophiuchus. In about 40,000 years it will pass within roughly 1.6 light-years of a star called Gliese 445, in the constellation Camelopardalis. Voyager 2 is heading toward the constellation Sagittarius. In about 40,000 years it will pass within roughly 1.7 light-years of a star called Ross 248.
Neither spacecraft is in any meaningful sense aimed at a particular star. They are simply flying outward, on whatever trajectory their planetary flybys left them on. They will continue to fly for as long as the universe lasts, unless they hit something, which they almost certainly will not.
What ends the mission
The mission will end, formally, when the spacecraft can no longer maintain communications with Earth. That moment is approaching. Engineers have been turning off science instruments one at a time for years to extend the power budget. By the late 2020s, only one or two instruments will still be operating. By the early 2030s, the spacecraft will be unable to power the heaters that keep their critical electronics above survival temperature, and shortly after that they will fall silent.
The spacecraft themselves will not stop existing. They will continue coasting outward through interstellar space, intact and inert, until something disturbs them. That disturbance, in the empty volumes between stars, is unlikely to happen on any timescale meaningful to humans.
Voyager 1 will outlast every human structure on Earth. It will outlast every human institution. It will, in all likelihood, outlast the human species. Its function will end. Its existence will not.
That is a strange thing to have built.