In 1977, NASA launched a pair of spacecraft that would forever redefine the limits of human exploration. Voyager 1 and Voyager 2 were designed as part of a grand tour of the outer planets, taking advantage of a rare planetary alignment. Today, these twin probes continue to send back data from the furthest reaches of space, boldly going where no spacecraft has gone before.
Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Despite the numerical order, Voyager 1's faster trajectory allowed it to overtake Voyager 2 and reach Jupiter and Saturn sooner.
The primary mission was to study the gas giants — Jupiter and Saturn — and their moons, rings, and magnetospheres. Voyager 2’s extended mission included flybys of Uranus and Neptune, making it the only spacecraft to have visited all four outer planets directly.
Both probes carried scientific instruments to study magnetic fields, cosmic rays, plasma, and interplanetary dust. Cameras on board captured stunning images that transformed our understanding of these distant worlds.
Each Voyager spacecraft carries a Golden Record, a 12-inch gold-plated copper disc containing sounds and images representing Earth’s diverse life and culture. These include music by Bach and Chuck Berry, greetings in 55 languages, and even the brainwaves of a young woman in love. The record is intended as a message to any extraterrestrial intelligence that may encounter the spacecraft.
“The spacecraft will be encountered and the record played only if there are advanced spacefaring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet.” — Carl Sagan
Voyager 1 is over 15 billion miles (24 billion km) from Earth, making it the most distant human-made object. It entered interstellar space in August 2012, when it passed beyond the heliopause — the boundary marking the end of the Sun’s influence.
Voyager 2 is currently over 12.7 billion miles (20.5 billion km) from Earth and entered interstellar space in November 2018. Both spacecraft are still operational and sending back scientific data via the Deep Space Network, albeit with greatly reduced bandwidth and power.
In 2024 and 2025, NASA engineers began turning off non-essential systems to conserve energy. Voyager 2 recently had its plasma instrument reactivated after an innovative power-saving tweak, reflecting just how resourceful the team continues to be.
The power source for both spacecraft — radioisotope thermoelectric generators (RTGs) — continues to decay. Current estimates suggest that communications may be possible until 2026–2030, depending on system reliability and remaining power. Instrumentation will be selectively shut down until finally, only the transmitter may remain on — and then, only silence.
Even after they fall silent, the Voyagers will continue drifting through the Milky Way. Voyager 1 is headed toward the constellation Ophiuchus and will pass within 1.6 light years of the star Gliese 445 in about 40,000 years. Voyager 2 is on a different trajectory, also toward interstellar nothingness.
The Voyager mission represents one of humanity’s greatest technological and scientific achievements. From planetary science to astrophysics, the data returned has shaped our understanding of the solar system and the space beyond. The Golden Records, meanwhile, carry our hopes, sounds, and music into eternity.
Perhaps, billions of years from now, long after Earth is dust, a Voyager spacecraft will still be travelling — an inert, drifting ambassador of a species that once looked to the stars and said, "Let’s go."