Interstellar probeOperational since 1977

Voyager 1

The most distant human-made object: a 1970s spacecraft that completed the first Grand Tour of the giant planets and became the first to reach interstellar space.

Launched 5 September 1977 · crossed the heliopause in 2012 · still returning science from beyond the Sun’s bubble

Mission status: Active interstellar mission
Launch: 5 September 1977 · Cape Canaveral
Heliopause crossing: 25 August 2012 · about 121 AU
Planetary encounters: Jupiter and Saturn only
Power: Three radioisotope thermoelectric generators
Communications: NASA Deep Space Network · radio
Special cargo: The Golden Record
Distance today: About 172 AU, updated below

Where Voyager 1 is now

Distance, speed and direction come from NASA/JPL Horizons. The numbers advance while this page is open.

Flight model · checking

Distance from Sun 172.180 AU 25,757.8 million km

Heliocentric speed 16.92 km/s about 60,900 km/h

One-way light time 23 h 52 min round trip is twice as long

Ecliptic longitude 256.8° Sun-centered direction

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NASA/JPL reference state
Sun-centered ecliptic J2000 vector

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How this position is calculated

NASA/JPL Horizons supplies a geometric state vector in a Sun-centered ecliptic J2000 frame. A fresh vector is requested when the page opens; between requests the browser propagates it with the reported velocity.

One trajectory, two giant worlds

Voyager 1 launched after its twin but took the faster route. It passed Jupiter in March 1979, revealing Io’s volcanoes, then encountered Saturn in November 1980. A close pass by Titan bent its path north and out of the planetary plane, ending its tour of the outer planets.

That choice traded Uranus and Neptune for the first close-up view of Titan, a moon with a thick atmosphere. It also sent Voyager 1 toward the heliopause sooner than Voyager 2.

5 Sep 1977Launch from Cape Canaveral and departure into an Earth-escape trajectory.
5 Mar 1979Closest approach to Jupiter, including the discovery of active volcanism on Io.
12 Nov 1980Saturn encounter and a close pass by Titan that redirected the spacecraft out of the ecliptic.
14 Feb 1990The Family Portrait and Pale Blue Dot, the final image sequence commanded from Earth.
25 Aug 2012Crosses the heliopause and enters the local interstellar medium.

Real images from the mission

NASA/JPL-Caltech

The Voyager spacecraft in its system test configuration at NASA's Jet Propulsion Laboratory — Voyager during system test configuration at NASA’s Jet Propulsion Laboratory. Image: NASA/JPL-Caltech.

Pale Blue Dot: Earth appears as a tiny point of light in a sunbeam in Voyager 1's final portrait — *Pale Blue Dot*, captured by Voyager 1 on 14 February 1990. Earth is the small point inside a scattered sunbeam. Image: NASA/JPL-Caltech.

What interstellar space is teaching us

Beyond the heliopause, Voyager 1 measures the plasma, magnetic field and energetic particles of the local interstellar medium. Repeated plasma-wave events give the electron density, while the magnetometer records how the interstellar magnetic field is distorted near the heliosphere.

The mission has helped show that the boundary is neither a smooth wall nor the edge of the Sun’s gravity. Voyager 1 is still inside a region influenced by the Sun and remains bound to it, while moving through material that originated beyond the heliosphere.

A spacecraft in a race against time

Every year the radioisotope generators produce less power. Heaters and instruments have been prioritised and switched off as the power budget shrinks, while the team balances science with keeping the spacecraft warm and controllable.

Power is always falling

The decay of plutonium-238 reduces generator output every year. Turning off an instrument or heater saves power immediately, but the choice may be irreversible.

Signals take hours

Radio travels at light speed. A command reaches Voyager 1 after nearly a day, and confirmation takes almost another day to return.

1970s hardware

Its computers have far less memory than a modern watch. Engineers maintain custom software, simulators and operating knowledge built around the original design.

The data rate is tiny

The fading signal is detected by enormous dish antennas and processed at extremely low bit rates. Deep Space Network time must be shared across many missions.

How NASA still controls Voyager 1

PlanMission engineers choose a safe power, thermal and science configuration.
EncodeCommands are assembled for the spacecraft’s original computers and cross-checked in simulators.
TransmitA Deep Space Network antenna sends a powerful uplink toward Voyager’s known position.
VerifyTelemetry returns hours later and confirms the command or triggers a recovery plan.

The antennas that keep listening

NASA/JPL-Caltech

Six Deep Space Network antennas at the Madrid complex arrayed together. Voyager’s control uses stations in California, Spain and Australia. Image: NASA/JPL-Caltech.

Selected mission publications

Year	Paper	Journal	Link
2024	Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au	Astrophysical Journal Letters	DOI
2019	Compressible and Incompressible Magnetic Turbulence Observed in the Very Local Interstellar Medium by Voyager 1	Astrophysical Journal	DOI
2014	Interstellar Magnetic Fields Observed by Voyager 1 beyond the Heliopause	Astrophysical Journal Letters	DOI

Worth knowing

Voyager 1 is farther away than any other human-made object.
Its radio signal is billions of times weaker by the time it reaches Earth.
It carries a gold-plated record containing sounds, music and images of Earth.

Watch the mission

Videos are embedded from YouTube and load only when a card is opened.

Follow the twin mission

The other Voyager