Voyager 1 will become humanity's first object to travel one light-day from Earth on Wednesday, Nov 18 2026, marking a historic milestone 49 years after its launch.
At more than 16 billion miles (26 billion km), the spacecraft will be farther than any human-made object, and its radio signals will take exactly 24 hours to reach Earth, a distance measured in one light-day.
NASA is planning a worldwide light-wave celebration on Tuesday after sunset, inviting people to use flashlights or phones to spell "VGR" in Morse code across the night sky.
Despite occasional glitches, Voyager 1 continues to transmit science and engineering data as it sails through interstellar space at 38 000 mph, while a small flight-control team at the Jet Propulsion Laboratory runs weekly commands and power-conservation maneuvers; a brief loss of contact in October is still under investigation.
Project manager Suzanne Dodd describes Voyager 1 as a national treasure and a source of wonder, highlighting its role as Earth's ambassador among the stars.