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NASA Voyager 1 & 2

NASA JPL · Interplanetary / Interstellar Probe / Outer Solar System / Interstellar Exploration · USA · Cold War (1970–1991)

NASA Voyager 1 & 2 — Interplanetary / Interstellar Probe / Outer Solar System / Interstellar Exploration
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Voyager 1 and Voyager 2 are NASA's two interstellar probes — the first man-made objects to leave the solar system. Built by NASA's Jet Propulsion Laboratory and launched in 1977 to perform a flyby tour of the outer planets, both spacecraft are still in-service in 2026, transmitting science data from beyond the heliopause at distances exceeding 24 billion km (Voyager 1) and 20 billion km (Voyager 2) from Earth — the most-distant in-service spacecraft in history. The probes carry the Voyager Golden Record, a 12-inch gold-plated copper phonograph disc with sounds and images of Earth.

Voyager 2 launched first, on 20 Aug. 1977; Voyager 1 followed on 5 September 1977. Voyager 1's faster trajectory let it reach Jupiter (March 1979), Saturn (November 1980), and then leave the planetary plane on a heliosphere-exit trajectory. Voyager 2 took the slower "Grand Tour" — Jupiter (July 1979), Saturn (Aug. 1981), Uranus (January 1986), Neptune (Aug. 1989) — taking advantage of a once-in-176-year planetary alignment that allowed gravity-assist flybys of all four outer planets. Voyager 2 remains the only spacecraft to have visited Uranus or Neptune.

Both spacecraft carry an identical instrument suite: cosmic-ray detectors, plasma-wave instruments, magnetometers, low-energy charged-particle detectors, and (originally) cameras + ultraviolet spectrometers (the imaging instruments were powered down decades ago to conserve electricity). Power comes from three radioisotope thermoelectric generators (RTGs) using plutonium-238 — output drops about 4 W per year as the plutonium decays, requiring NASA to progressively turn off instruments to maintain core operations.

Voyager 1 crossed the heliopause (the boundary between the Sun's heliosphere and interstellar space) on 25 Aug. 2012 — the first man-made object to enter interstellar space. Voyager 2 crossed on 5 November 2018. Both spacecraft continue to transmit plasma-wave and magnetometer data from interstellar space; round-trip light-time to Voyager 1 is now over 45 hours. NASA expects power output to drop below the threshold for science operations sometime in the 2030s; both spacecraft will continue silently coasting through interstellar space at about 17 km/s indefinitely. The next stellar encounter (Gliese 445) is in approximately 40,000 years.

For Kids — a shorter, friendlier version

The Voyager spacecraft — two identical robots called Voyager 1 and Voyager 2 — are the most-distant human-made objects in the universe. NASA launched them in 1977. They're still traveling outward today, almost 50 years later. As of 2026, Voyager 1 is over 15 billion miles from Earth, in interstellar space — the space between the stars.

The Voyagers were designed to fly past the outer planets and take photographs. Each Voyager is about as big as a small car. Voyager 1 visited Jupiter (1979) and Saturn (1980). Voyager 2 visited Jupiter, Saturn, Uranus (1986), and Neptune (1989).

The two robots gave humans our first close-up photos of those four planets and many of their moons. The mission was supposed to last only 5 years, but NASA kept it going. Each Voyager carries a special record called the Golden Record. It's a 12-inch gold-plated disc with sounds and pictures from Earth: whale songs, music from around the world, greetings in 55 languages, photographs of plants and animals. If an alien civilization ever finds a Voyager, the Golden Record is humanity's message to them.

The Voyagers are powered by special batteries that produce electricity from radioactive plutonium. The power slowly decreases each year. By 2030 or so, the batteries will be too weak to operate any instruments. The spacecraft will keep traveling forever, silent but still moving outward through space.

In about 40,000 years, Voyager 1 will pass about 1.6 light-years from a star called Gliese 445. Voyager 2 will pass near another star, Ross 248, around the same time.

Fun Facts

  • Voyager 1 is over 15 billion miles from Earth — the farthest human-made object ever.
  • Each Voyager carries a Golden Record with sounds, music, and pictures of Earth — humanity's message to aliens.
  • Both Voyagers launched in 1977 and are still working in 2026 — about 49 years.
  • Voyager 2 is the only spacecraft to visit Uranus (1986) and Neptune (1989).
  • Each Voyager is powered by radioactive plutonium batteries that will run out around 2030.
  • The Voyagers will keep flying forever after their batteries die — passing other stars in 40,000 years.
  • It takes about 22 hours for a radio signal from Voyager 1 to reach Earth — the distance is that great.

Kids’ Questions

What's on the Golden Record?

Each Voyager's Golden Record holds 116 photographs of Earth (people, animals, plants, cities), greetings in 55 different human languages, music from around the world (including Beethoven, Chuck Berry, and traditional songs from many cultures), and natural sounds (rain, whale songs, a baby crying). The record was put together by a team led by Carl Sagan in 1977. The idea: if any aliens ever find a Voyager spacecraft, they can play the record and learn about humanity. The Voyagers won't reach another star for tens of thousands of years, so the Golden Record is a very, very long-term message.

When will the Voyagers stop working?

The Voyagers are powered by special batteries called RTGs (Radioisotope Thermoelectric Generators) that produce electricity from heat generated by radioactive plutonium. The plutonium slowly decays over time, so each year the batteries make less power. Scientists at NASA have been gradually turning off instruments to save power. By 2030 or so, the Voyagers won't have enough power to operate any instruments. The spacecraft will go silent. But they'll keep flying forever through interstellar space, moving at about 35,000 mph. They'll outlast Earth itself.

Variants

Voyager 1
Launched 5 September 1977 on Titan IIIE-Centaur. Faster outer-planet-flyby trajectory: Jupiter (March 1979), Saturn (November 1980), then heliosphere-exit. Crossed heliopause 25 Aug. 2012.
Voyager 2
Launched 20 August 1977 (16 days before Voyager 1) on slower Grand Tour trajectory: Jupiter (July 1979), Saturn (Aug. 1981), Uranus (January 1986), Neptune (Aug. 1989). Crossed heliopause 5 November 2018. Only spacecraft ever to visit Uranus or Neptune.

Notable Operators

NASA / Jet Propulsion Laboratory
Designer, builder, and sole operator. Mission control at JPL in Pasadena, California. Communications via NASA's Deep Space Network (DSN) — round-trip light-time to Voyager 1 now exceeds 45 hours.

Frequently Asked Questions

Where are the Voyager probes now?

As of 2026: Voyager 1 is approximately 24 billion km from Earth (about 162 AU) in the constellation Ophiuchus, in interstellar space beyond the heliopause. Voyager 2 is approximately 20 billion km away (about 135 AU) in the constellation Pavo, also in interstellar space. Both are travelling at about 17 km/s.

Are the Voyagers still working?

Yes — both spacecraft continue to transmit science data in 2026, primarily from plasma-wave and magnetometer instruments. Imaging instruments were powered down decades ago to conserve power. NASA expects power output (from radioactive decay of the plutonium-238 RTG sources) to drop below the science-operations threshold sometime in the 2030s.

Will the Voyagers ever reach another star?

The first stellar encounter is in approximately 40,000 years, when Voyager 1 will pass within 1.6 light-years of the M-dwarf star Gliese 445. The probes will then drift in the galactic disk for billions of years; both spacecraft (and the Golden Records they carry) will likely outlive Earth itself.

What is the Voyager Golden Record?

A 12-inch gold-plated copper phonograph disc, one mounted on each spacecraft, containing 116 photographs of Earth, greetings in 55 languages, music samples (Beethoven, Chuck Berry, Mongolian throat-singing, Indian raga, etc.), and sounds of Earth (whales, thunder, a baby crying, etc.). The cover engravings give pulsar map directions to find Earth and basic chemistry instructions to play the disc. Designed by a committee chaired by Carl Sagan.

When did Voyager leave the solar system?

Voyager 1 crossed the heliopause — the boundary between the Sun's heliosphere and interstellar space — on 25 Aug. 2012. Voyager 2 crossed on 5 November 2018. Both spacecraft now travel through interstellar space, the first man-made objects ever to do so. Note that the Sun's gravitational influence (the Oort cloud) extends much farther; the heliopause is the boundary of the solar magnetic field, not gravity.

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