Voyager 1 facts for kids

For other uses, see Voyager 1 (disambiguation).

Quick facts for kids
*Voyager 1*
Spacecraft properties
Artist's rendering of the Voyager spacecraft

Mission type	Outer planetary, heliosphere, and interstellar medium exploration
Operator	NASA/Jet Propulsion Laboratory
Mission duration	Total: 49 years, 5 days (elapsed) Planetary mission: 3 years, 3 months, 9 days Interstellar mission: 45 years, 270 days (elapsed)


Spacecraft type	Mariner Jupiter-Saturn
Manufacturer	Jet Propulsion Laboratory
Launch mass	815 kg (1,797 lb)
Dry mass	721.9 kg (1,592 lb)
Power	470 watts (at launch)


Start of mission
Launch date	September 5, 1977, 12:56:01 (1977-09-05UTC12:56:01Z) UTC
Rocket	Titan IIIE
Launch site	Cape Canaveral Launch Complex 41


Flyby of Jupiter
Closest approach	March 5, 1979
Distance	349,000 km (217,000 mi)
Flyby of Saturn
Closest approach	November 12, 1980
Distance	124,000 km (77,000 mi)
Flyby of Titan (atmosphere study)
Closest approach	November 12, 1980
Distance	6,490 km (4,030 mi)

Large Strategic Science Missions Planetary Science Division ← Voyager 2 Galileo →

Voyager 1 is an unmanned robotic space probe launched by NASA on September 5, 1977. It is part of the famous Voyager program created to explore the outer Solar System and the mysterious regions of interstellar space. Launched just 16 days after its twin craft, Voyager 2, it remains the farthest human-made object from Earth.

The spacecraft communicates across billions of kilometers using the NASA Deep Space Network (DSN). Flying at tremendous speeds, Voyager 1 travels through deep space far beyond the planets. It provides scientists with direct measurements of the outer frontier of our cosmic neighborhood.

During its primary mission, Voyager 1 completed historic flybys of Jupiter, Saturn, and Saturn's largest moon, Titan. It discovered active volcanoes, complex ring systems, and mysterious new moons. These historic planetary encounters revolutionized our understanding of the giant gas planets.

After finishing its planetary tour, the spacecraft began an extended journey outward. On August 25, 2012, Voyager 1 crossed the heliopause to become the first human-built craft to reach interstellar space. It carries a special message called the Voyager Golden Record for any intelligent extraterrestrial life that might discover it in the distant future.

Mission Background and Planning for Deep Space Exploration
Timeline of Historic Space Flight Milestones
- Chronological Log of Important Mission Events
- Rocket Launch and Orbital Path
Scientific Discoveries at the Giant Planets
- Exploring Jupiter and Its Moons
- Encounters with Saturn, Titan, and the Ring System
Journey Beyond the Solar System Boundary
- Crossing the Outer Heliosphere and Termination Shock
- Entering Interstellar Space at the Heliopause
Future Milestones and Long-Term Space Travel
- Spacecraft Operations and Engineering Challenges
- Ultimate Destination Among the Stars
The Golden Record: Earth's Message to the Cosmos
See also

Mission Background and Planning for Deep Space Exploration

During the 1960s, aerospace scientists noticed an uncommon geometric arrangement of the outer planets. This rare planetary alignment happens only once every 175 years. It offered a unique chance to send a robotic craft to multiple outer worlds using gravity assist maneuvers.

Scientists originally conceived a plan known as the Planetary Grand Tour. This ambitious concept aimed to explore Jupiter, Saturn, Uranus, Neptune, and Pluto with pairs of advanced probes. Although budget adjustments changed the original scope, NASA designed the twin Voyager spacecraft to carry out these essential exploration goals.

Designing the Voyager 1 Spacecraft

The 3.7 m (12 ft) diameter high gain dish antenna used on the Voyager craft

Voyager 1 was built by the Jet Propulsion Laboratory (JPL) in California. The spacecraft body uses a sturdy ten-sided prism structure known as a bus. Attached to this central hub are long deployable booms that hold sensitive science instruments away from electrical interference.

To control its orientation in the vacuum of space, the craft uses 16 liquid hydrazine thrusters. Miniature three-axis stabilization gyroscopes and celestial reference sensors help keep the probe balanced. These systems ensure that the primary antenna remains pointed directly toward Earth across vast interplanetary distances.

Long-Distance Communication and Radio Links

Communication across outer space requires powerful and highly focused radio systems. Voyager 1 carries a large dish antenna with a diameter of 3.7 m (12 ft). This high-gain antenna focuses radio waves into narrow beams directed back to Earth.

Three massive ground stations belonging to the NASA Deep Space Network track the spacecraft from locations in California, Spain, and Australia. Radio signals traveling at the speed of light take almost an entire day to travel one way between the probe and Earth. If transmission is interrupted, an onboard magnetic tape recorder stores scientific data for later playback.

Long-Lasting Nuclear Power Sources

Diagram of RTG fuel container, showing plutonium-238 oxide spheres

Because the outer Solar System receives very little sunlight, standard solar panels cannot power the probe. Instead, Voyager 1 relies on three radioisotope thermoelectric generators (RTGs). These compact power units convert heat released by the natural decay of plutonium-238 into usable electricity.

At launch, the generators produced about 470 watts of electrical power. Over many decades, the radioactive material steadily decays and reduces total power output. Engineers carefully turn off non-essential heaters and instruments to keep key science sensors running as long as possible.

Flight Computers and Navigation Technology

The probe depends on three specialized computer systems that work together to manage all operations. The Computer Command Subsystem (CCS) stores routine instructions, decodes instructions sent from Earth, and oversees autonomous safety routines.

The Flight Data Subsystem (FDS) gathers scientific data from each sensor and prepares it for transmission. The Attitude and Articulation Control Subsystem (AACS) continuously monitors the position of the spacecraft and points science instruments toward celestial targets.

Scientific Instruments and Research Tools

Locations of Voyager's scientific instruments

Voyager 1 was equipped with 11 advanced scientific instruments to examine atmospheres, magnetic fields, space plasma, and cosmic radiation:

Instrument name	Abbr.	Description
Imaging Science System (disabled)	(ISS)	Used a two-camera system (narrow-angle and wide-angle) with multiple color filters to capture detailed images of planets and moons. Turned off in 1990 to conserve electric power.
Radio Science System (disabled)	(RSS)	Used radio signals to study atmospheric structure, planetary rings, and precise gravitational fields during close flybys.
Infrared interferometer spectrometer and radiometer (disabled)	(IRIS)	Measured infrared light to investigate atmospheric temperatures, atmospheric gases, and thermal qualities of rings.
Ultraviolet Spectrometer (disabled)	(UVS)	Examined ultraviolet light to determine upper atmospheric chemistry and radiation characteristics of distant planetary bodies.
Triaxial Fluxgate Magnetometer (active)	(MAG)	Measures magnetic fields around planets and tracks changes in interstellar magnetic environments. It remains fully operational.
Plasma Spectrometer (defective)	(PLS)	Designed to detect low-energy plasma ions and electrons. It stopped operating properly in the 1980s.
Low Energy Charged Particle Instrument (disabled)	(LECP)	Measured the energy and flow of electrons, protons, and energetic ions in space environments.
Cosmic Ray System (disabled)	(CRS)	Detected high-energy energetic particles originating from solar flares and energetic galactic sources.
Planetary Radio Astronomy Investigation (disabled)	(PRA)	Monitored radio emissions generated by the atmospheres and magnetospheres of Jupiter and Saturn.
Photopolarimeter System (defective)	(PPS)	Used polarized light sensors to examine atmospheric particles and surface textures of moons.
Plasma Wave Subsystem (active)	(PWS)	Measures waves in ionized gas generated by energetic particle interactions. It remains active in interstellar space.

Timeline of Historic Space Flight Milestones

Voyager 1's trajectory seen from Earth, diverging from the ecliptic in 1981 at Saturn and now heading towards the constellation Ophiuchus

Chronological Log of Important Mission Events

Date	Event
1977-09-05	Spacecraft launched at 12:56:00 UTC.
1977-12-10	Entered the asteroid belt.
1977-12-19	Voyager 1 overtook its twin sister craft, Voyager 2.
1978-09-08	Safely exited the asteroid belt without incident.
1979-01-06	Began the official scientific observation phase of Jupiter.
1979-03-05	Closest approach to Jupiter and its inner moons.
1980-08-22	Began the long-range observation phase of Saturn.
1980-11-12	Closest approach to Saturn and its major moon Titan.
1980-11-14	Concluded its planetary flybys and began the extended interstellar mission.
1990-02-14	Took the famous Family Portrait photograph of the Solar System.
1998-02-17	Overtook Pioneer 10 to become the most distant human-made object.
2004-12-15	Crossed the termination shock to enter the outer heliosheath.
2012-08-25	Crossed the heliopause and entered deep interstellar space.
2024-04-22	Flight engineers successfully restored computer telemetry after code relocation.

Rocket Launch and Orbital Path

Voyager 1 lifted off atop a Titan IIIE.

An animation of Voyager 1's trajectory from September 1977 to December 31, 1981
Voyager 1 · Earth · Jupiter · Saturn · Sun

Voyager 1 lifted off on September 5, 1977, from Cape Canaveral Air Force Station in Florida. It rode atop a powerful Titan IIIE rocket equipped with a high-energy Centaur upper stage. Even though it launched two weeks after Voyager 2, it flew along a faster trajectory that brought it to Jupiter first.

During the launch ascent, the rocket's second stage burned slightly less propellant than intended. Fortunately, the smart guidance computer on the Centaur stage detected this shortfall. The Centaur extended its own rocket burn, reaching orbital speed just seconds before running out of fuel.

The spacecraft was placed onto an interplanetary transfer orbit heading directly toward the outer planets. As it traveled outward, the craft smoothly crossed the asteroid belt without encountering hazardous debris.

Scientific Discoveries at the Giant Planets

Exploring Jupiter and Its Moons

An animation of Voyager 1's trajectory around Jupiter
Voyager 1 · Jupiter · Io · Europa · Ganymede · Callisto

Voyager 1 made its closest approach to Jupiter on March 5, 1979. It passed within 349,000 kilometres (217,000 miles) of the giant planet's turbulent cloud tops. The probe captured thousands of high-resolution images of swirling storms, including intricate details inside the massive Great Red Spot.

One of the most astonishing discoveries occurred on the moon Io. Images showed towering volcanic plumes erupting sulfur high above its surface. This marked the very first time active volcanoes were discovered on another world in our Solar System.

The spacecraft also discovered a faint, dusty ring system circling Jupiter. In addition, it found two previously unknown small moons named Metis and Thebe. Images of icy Europa revealed a smooth, fractured surface hinting at a hidden liquid water ocean below.

Jupiter's Great Red Spot as seen from Voyager 1
Voyager 1 composite image of Jupiter and its moons Europa (right) and Io (left) taken on the final day of Voyager 1's Jupiter encounter.
Voyager 1 image of Valhalla, a multi-ring impact structure 3,800 km in diameter on Callisto.
Voyager 1 image of Europa.
Voyager 1 image of Perrine Regio on Ganymede.
Voyager 1 mosaic covering Io's south polar region.
Voyager 1 image of a volcanic eruption on Io 11 hours before closest approach.

Encounters with Saturn, Titan, and the Ring System

Using Jupiter's immense gravity as a slingshot, Voyager 1 accelerated toward Saturn. The probe arrived in November 1980, skimming within 124,000 kilometres (77,000 miles) of the planet's golden atmosphere. Its cameras captured breathtaking views of thousands of individual ringlets, dynamic ring waves, and mysterious dark spoke features.

The spacecraft completed a close flyby of Saturn's giant moon Titan. Scientists wanted to investigate Titan because it possesses a dense, nitrogen-rich atmosphere. Measurements revealed that the moon is blanketed in a thick orange haze of complex organic molecules.

The flyby trajectory around Titan bent the probe's flight path upward and away from the orbital plane of the planets. This path prevented the spacecraft from traveling onward to Uranus or Neptune. However, the data gathered from Titan provided crucial knowledge about planetary atmospheres.

Crescent Saturn from 5.3 million km, four days after closest approach
Voyager 1 image of Saturn's narrow, twisted and braided F Ring.
Mimas at a range of 425,000 km. The crater Herschel is at upper right
Tethys, with its giant rift valley Ithaca Chasma, from 1.2 million km.
Fractured 'wispy terrain' on Dione's trailing hemisphere.
The icy surface of Rhea is nearly saturated with impact craters.
Titan's thick haze layer is shown in this enhanced Voyager 1 image.
Layers of haze, composed of complex organic compounds, covering Saturn's satellite Titan.

Journey Beyond the Solar System Boundary

The Family Portrait of the Solar System acquired by Voyager 1, February 14, 1990

The position of Voyager 1 above the plane of the ecliptic on February 14, 1990, the day Family Portrait was taken.

Voyager 1 and 2 speed and distance from the Sun

The Pale Blue Dot image showing Earth from 6 billion kilometers (3.7 billion miles) appearing as a tiny dot within deep space.

On February 14, 1990, Voyager 1 pointed its cameras back toward the inner Solar System. It captured a wide mosaic of portraits showing six planets against the dark sky. Among these pictures was the iconic Pale Blue Dot, showing Earth as a tiny speck of light suspended in a sunbeam.

Shortly after taking these historic photos, NASA turned off the cameras to preserve electrical power and onboard computing memory. The spacecraft then dedicated its remaining energy to tracking magnetic fields and charged particles.

Crossing the Outer Heliosphere and Termination Shock

Close flybys of gas giants gave gravity assists to both Voyagers

The Sun generates a vast bubble of solar wind and magnetic fields known as the heliosphere. In December 2004, at a distance of 94 astronomical units (AU) from the Sun, Voyager 1 crossed the termination shock. At this boundary, the supersonic solar wind suddenly slows down upon meeting interstellar matter.

Passing through the termination shock brought the craft into the heliosheath, the turbulent outer border zone of the Sun's influence. Here, solar particles interact directly with gas and dust flowing from other stars.

Entering Interstellar Space at the Heliopause

On August 25, 2012, Voyager 1 officially crossed the heliopause at a distance of 121 AU. The heliopause represents the outer boundary where the solar wind gives way completely to the interstellar medium.

Sensors on the probe recorded a sharp drop in solar particles and a dramatic surge in galactic cosmic rays. By detecting vibrations in surrounding interstellar plasma waves, scientists confirmed that Voyager 1 was traveling through true interstellar space.

Plot showing a dramatic increase in the rate of cosmic ray particle detection by the Voyager 1 spacecraft, October 2011 to October 2012
Plot showing a dramatic decrease in the rate of solar wind particle detection by Voyager 1, October 2011 to October 2012

Voyager 1 and the other probes that are in or on their way to interstellar space, except New Horizons.

Future Milestones and Long-Term Space Travel

Interstellar velocity ( $v_\infty$ )
Probe	Velocity ( $v_\infty$ )
Pioneer 10	11.8 km/s (2.49 au/yr)
Pioneer 11	11.1 km/s (2.34 au/yr)
Voyager 1	16.9 km/s (3.57 au/yr)
Voyager 2	15.2 km/s (3.21 au/yr)
New Horizons	12.6 km/s (2.66 au/yr)

Spacecraft Operations and Engineering Challenges

An image of Voyager 1's radio signal on February 21, 2013.

Operating a deep space probe across billions of kilometers presents unique engineering challenges. In late 2023, a faulty memory chip in the Flight Data Subsystem caused the spacecraft to send scrambled telemetry back to Earth.

JPL engineers analyzed the problem and devised a clever software fix. They divided the computer code into smaller segments and relocated it to undamaged memory locations. In April 2024, regular communication was successfully restored, allowing science instruments to send data once again.

As electrical power gradually declines, NASA systematically switches off instruments to keep basic transmitters operating. While the probe will eventually lose electrical power, its silent metal structure will continue traveling indefinitely through the galaxy.

Ultimate Destination Among the Stars

In about 50,000 years Voyager 1 will be as distant as several nearby stars

In about 300 years, Voyager 1 will reach the inner boundary of the distant Oort cloud, a vast halo of icy comets surrounding our Solar System. It will take roughly 30,000 years for the probe to pass entirely through this icy cloud.

In roughly 40,000 years, the spacecraft will glide within 1.6 light-years of the red dwarf star Gliese 445 in the constellation Camelopardalis. Free from atmospheric drag and cosmic erosion, Voyager 1 will wander silently among the stars of the Milky Way for millions of years.

The Golden Record: Earth's Message to the Cosmos

Voyager Golden Record

Mounted safely to the side of Voyager 1 is a gold-plated copper phonograph disc known as the Voyager Golden Record. A scientific committee chaired by astronomer Carl Sagan assembled the record to introduce Earth to any extraterrestrial civilization that might discover the probe.

The record contains 115 images showing natural landscapes, human anatomy, scientific diagrams, and diverse cultures. It includes natural audio recordings of ocean surf, thunder, wind, bird songs, and whale calls. Spoken greetings in 55 languages and a diverse collection of classical and traditional music celebrate human creativity across our home planet.