Voyager Mission — 50th Anniversary (Voyager 1 launch)

What this countdown tracks

The 50th anniversary of the launch of Voyager 1 — Sunday, September 5, 2027. NASA's Voyager 1 spacecraft launched at 12:56 UTC on September 5, 1977 atop a Titan IIIE-Centaur rocket from Cape Canaveral. Voyager 2 had launched 16 days earlier, on August 20, 1977. Both spacecraft remain operational in interstellar space in 2027 — by far the longest-running space mission in history.

About this anniversary

The Voyager program was conceived in the early 1970s to take advantage of a once-in-176-years planetary alignment that allowed a single spacecraft to fly past Jupiter, Saturn, Uranus and Neptune using gravity assists at each. Voyager 2 was launched first because it would take the slower trajectory through all four outer planets (a "Grand Tour"); Voyager 1 was launched second on a faster trajectory that prioritised Jupiter and Saturn. Both spacecraft carried the famous Golden Record — a phonographic record of sounds, images, music, and greetings in 55 languages, designed by a committee chaired by Carl Sagan as a message to any extraterrestrial civilisation that might intercept the spacecraft.

By 2027 the Voyager mission's achievements are already vast: the first detailed images of Jupiter's moons (1979), the discovery of Io's volcanism, the first detailed images of Saturn (1980–81), the first close imaging of Uranus (1986) and Neptune (1989), the first measurements at the heliopause (Voyager 1, 2012), and the first measurements in pure interstellar space (Voyager 2, 2018). At the 50th anniversary in September 2027, both spacecraft are still operating on dwindling Plutonium-238 RTG power — Voyager 1 at approximately 165 AU (24.7 billion km) from the Sun, Voyager 2 at approximately 138 AU (20.6 billion km), both moving outward at about 17 km/s.

The mission is expected to lose power for sustaining instrument operations between 2025 and 2030. NASA's mission engineers have systematically powered down secondary systems to extend the operational life of the Voyagers' magnetometer, plasma wave subsystem, and cosmic ray subsystem. The 50th-anniversary year of 2027 is likely to coincide with the powering-down of one or both Voyagers' final instruments — making the 50th the last major active-mission anniversary.

What to expect

NASA's principal commemoration is at the Jet Propulsion Laboratory in Pasadena, California — Voyager mission control since launch, where a small operations team continues to send and receive Voyager commands and data via the Deep Space Network. JPL is expected to host an in-person 50th-anniversary symposium with the Voyager mission's surviving original team, the current operations team, and an extended NASA-and-academic programme.

The Voyager Golden Record, still travelling outbound at 17 km/s on each spacecraft, is expected to be a focus of the anniversary. The Carl Sagan Institute at Cornell, the Library of Congress (which holds the master Golden Record), and the Voyager team have collectively curated the Golden Record's history; a 50th-anniversary edition Golden Record album was already issued in 2017 (40th anniversary) and a follow-up release for 2027 is anticipated. The Voyager Golden Record committee's surviving members — including Ann Druyan (Sagan's widow and the project's creative director) — are expected to speak.

The deep space scientific community is expected to coordinate symposia at the AGU Fall Meeting (December 2027), the AAS Division for Planetary Sciences meeting, and the American Institute of Aeronautics and Astronautics. The Smithsonian National Air and Space Museum, the JPL Visitor Center, and major science museums (Boston Museum of Science, the Adler Planetarium, the California Academy of Sciences) are expected to mount Voyager 50th-anniversary exhibitions.

Past Voyager milestones

• November 5, 2018 — Voyager 2 enters interstellar space
• August 25, 2012 — Voyager 1 enters interstellar space
• February 14, 1990 — "Pale Blue Dot" image taken by Voyager 1 from 6 billion km
• August 25, 1989 — Voyager 2 closest approach to Neptune
• January 24, 1986 — Voyager 2 closest approach to Uranus
• November 12, 1980 — Voyager 1 closest approach to Saturn
• March 5, 1979 — Voyager 1 closest approach to Jupiter

How to follow

NASA's Voyager website (voyager.jpl.nasa.gov) publishes mission status and the 50th-anniversary programme. The Library of Congress and the Carl Sagan Institute coordinate Golden Record observances. The Jet Propulsion Laboratory and Caltech host the principal symposium. Major science journalism — Sky & Telescope, Nature, Scientific American, The Planetary Society — provides extensive coverage. Ann Druyan and the Voyager team's official documentary archives are housed at JPL.

Related countdowns

The Voyager 50th anniversary aligns with NASA's broader space-mission anniversary cycle including Apollo 11 60th anniversary 2029 and the NASA Roman Space Telescope launch 2026. See also Pioneer 11 50th, iPhone 20th anniversary 2027, and the broader Total solar eclipse August 2 2027 sky calendar of 2027.

FAQ

When is the Voyager 50th anniversary? Sunday, September 5, 2027 — for Voyager 1 (launched September 5, 1977). Voyager 2 launched August 20, 1977. Are the Voyagers still operating? Yes — both spacecraft remain operational in interstellar space, with limited instruments active on dwindling RTG power; full mission end is expected between 2025 and 2030. Where are the Voyagers in 2027? Voyager 1 is approximately 165 AU (24.7 billion km) from the Sun; Voyager 2 is approximately 138 AU. Both are moving outward at about 17 km/s. What's on the Golden Record? Sounds, images, music, and greetings in 55 languages, designed by a committee chaired by Carl Sagan; the Library of Congress holds the master.