The Farthest Machine: Voyager 1 Leaves Earth

On 5 September 1977, a Titan IIIE-Centaur rocket lifted off from Cape Canaveral carrying a one-ton spacecraft named Voyager 1. It launched sixteen days after its twin, Voyager 2, but on a faster trajectory that soon put it in front — a lead it has never surrendered. No machine humans have built has ever traveled farther. [1]

A once-in-176-years alignment

The Voyagers exploited a rare geometric gift: a late-1970s alignment of the outer planets that allowed a spacecraft to slingshot from world to world using each planet’s gravity — an arrangement that recurs roughly every 176 years. [1] Voyager 1’s itinerary was Jupiter and Saturn. Its 1979 Jupiter flyby returned images of the planet’s roiling storms and discovered active volcanoes on the moon Io — the first ever seen beyond Earth. At Saturn in 1980, mission planners deliberately spent the spacecraft’s planetary future on a close pass of the haze-shrouded moon Titan, a maneuver that bent its path up and out of the plane of the planets. [2] [3]

The pale blue dot

In February 1990, past the orbits of the planets, Voyager 1 turned its camera back and took a final family portrait of the solar system. In one frame, Earth spans less than a pixel — the image Carl Sagan made famous as the “Pale Blue Dot.” [3] In August 2012, its instruments registered the boundary where the Sun’s wind gives way to the plasma of the galaxy: Voyager 1 had become the first spacecraft to enter interstellar space. [2]

A message in a bottle

Bolted to the spacecraft’s side is the Golden Record, a gold-plated copper phonograph disc curated by a committee chaired by Sagan: greetings in dozens of languages, music from Bach to Chuck Berry, the sounds of surf and heartbeat, and instructions — written in the language of physics — for playing it. [1] It is a message with an intended shelf life of a billion years, addressed to no one in particular.

Still transmitting

Powered by slowly decaying plutonium, Voyager 1 still radios data across more than a light-day of distance, though its instruments are being switched off one by one as the power budget shrinks. [2] Sometime in the coming years the signal will fall silent, and the mission will enter its longest phase: a silent artifact of 1977, drifting outward through the galaxy, outliving everything else its makers ever made.