Voyager 1
Humanity's farthest emissary — 24+ light-hours from Earth and still phoning home, nearly half a century after launch.
Vital statistics
01
Overview
Voyager 1 is the most distant human-made object in the universe. Launched on September 5, 1977, after its twin Voyager 2, it used a Jupiter gravity assist to whip outward at record speed, then conducted close flybys of Saturn and its moon Titan in 1980. Since then it has cruised in a straight line at 17 km/s, crossing the heliopause into interstellar space on August 25, 2012 — the first spacecraft ever to do so. From over 24 billion kilometres away, its plasma-wave and magnetometer instruments still send back data that takes 22 hours to reach Earth at the speed of light.
02
Composition
Voyager 1 carries a 3.7-metre high-gain dish antenna, three radioisotope thermoelectric generators (RTGs) fueled by plutonium-238, a magnetometer on a 13-metre boom, and a suite of plasma, cosmic-ray, and ultraviolet instruments. Most cameras and heaters were powered down decades ago to conserve electricity; the remaining instruments draw ~225 W as the RTGs slowly decay. Each Voyager also carries a 12-inch gold-plated copper Golden Record bearing greetings, music, and images encoded for any intelligence that might one day intercept it.
05
Exploration
Voyager 1 returned the first close-up images of Jupiter's Great Red Spot and its moons in 1979, then revealed Saturn's ring structure and Titan's thick nitrogen atmosphere in 1980. Mission planners traded a Pluto encounter for Titan, sending Voyager 1 above the ecliptic plane on a one-way trajectory out of the solar system. After the planetary tour ended, the Voyager Interstellar Mission began: the probe still measures interstellar plasma density, magnetic field, and cosmic rays from beyond the heliosphere. As of 2024, JPL was still successfully troubleshooting onboard memory faults from across light-hours.
Did you know?
Voyager 1 launched 16 days AFTER Voyager 2 — but on a faster trajectory that overtook it.
Its Pale Blue Dot photograph of Earth from 6 billion km away (1990) was Carl Sagan's idea.
Each command from Earth takes ~22 hours to arrive at Voyager 1; replies take another 22 hours.
The plutonium-238 in its RTGs has a 87.7-year half-life and is now too depleted to power all instruments simultaneously.
Voyager 1's Golden Record is expected to remain readable for at least one billion years.
It is currently moving toward the constellation Ophiuchus and will pass within 1.6 light-years of star Gliese 445 in about 40,000 years.
NASA expects to lose contact around 2030 once RTG output drops below the minimum needed for the radio.
Timeline
- 19771977
Voyager 1 launches on a Titan IIIE / Centaur from Cape Canaveral on September 5.
- 19791979
Closest approach to Jupiter on March 5 — discovers volcanism on Io and the rings.
- 19801980
Closest approach to Saturn on November 12 — Titan flyby ends planetary mission.
- 19901990
Captures the Pale Blue Dot image of Earth from 6 billion km on February 14.
- 19981998
Overtakes Pioneer 10 to become the farthest human-made object from Earth.
- 20122012
Crosses the heliopause on August 25, entering interstellar space.
- 20242024
JPL recovers from a months-long memory fault, restoring engineering data downlink.
- planned ~2030planned ~2030
Final loss of contact expected as RTG power drops below minimum.