NASA spacecraft Voyager 1 nears one light-day distance milestone in deep space

NASA's Voyager 1 spacecraft is about to reach a distance of one light-day from Earth as it travels through interstellar space. The milestone means radio signals will take precisely 24 hours to travel between the spacecraft and Earth at the speed of light when it hits the mark on Wednesday, November 18, 2026. Launched 49 years ago, the probe is now more than 26 billion kilometres away from home.

Mission Details And Operations

Project manager Suzanne Dodd describes Voyager 1 as a national treasure and an ambassador hurtling between stars. To mark the occasion, NASA is asking people to use their phones or flashlights to create a wave of golden light after sunset on Tuesday, November 17, spelling the letters V-G-R in Morse code. Despite old age and occasional problems, Voyager 1 and its twin Voyager 2 keep sending science and engineering data at 61,000 kilometres per hour. Voyager 2, launched two weeks before its sibling in 1977, will not reach the one light-day mark until 2035. Voyager 1 swept past Jupiter and Saturn in 1979 and 1980 before leaving the solar system in 2012, while Voyager 2 visited those two planets plus Uranus and Neptune before entering interstellar space in 2018.

Challenges And History

A skeleton flight control team at NASA's Jet Propulsion Laboratory in Pasadena, California, sends commands about once a week, aided at times by retirees. In September, controllers finished a power-conserving effort for the plutonium-powered craft, though they briefly lost contact in October and are still investigating the disruption. Beyond its distance record, Voyager 1 captured the famous Pale Blue Dot picture of Earth from beyond Neptune in 1990. Each twin also carries a 30-centimetre gold-plated phonographic record created under the guidance of astronomer Carl Sagan, featuring greetings in 55 languages, images, and sounds as a time capsule of life on Earth.

Context

Deep space probes like Voyager 1 rely on radio waves to communicate with Earth over immense cosmic distances, meaning messages take hours or even a full day to travel one way. These long-running missions gradually face declining power supplies from their radioactive plutonium power sources, requiring engineers to carefully manage onboard systems to keep instruments functioning decades after launch.