In late 2026, NASA’s iconic Voyager 1 spacecraft will reach an impressive milestone. The probe is set to become the first spacecraft to reach a distance of one light day from our planet.
Voyager 1 is already the first human spacecraft to reach interstellar space and the farthest human-made object from Earth. The new milestone will be achieved when it takes 24 hours for radio signals—essentially light—to reach the spacecraft.
NASA’s Voyager 1 light-day milestone
Impressively, it will have taken almost 50 years for Voyager 1 to reach a distance of one light day from Earth. Right now, it is roughly 15.7 billion miles (25.3 billion km) from Earth. According to NASA, it currently takes around 23 hours, 32 minutes, and 35 seconds for a message to reach the spacecraft.
However, in about a year, Voyager 1 will be 16.1 billion miles (25.9 billion km) from Earth. When it reaches that distance, it will take a signal 24 hours to reach the spacecraft. NASA estimates this will take place around November 15, 2026.
Of course, at this distance, communicating with the spacecraft becomes increasingly complicated.
NASA can continue communicating with the historic probe thanks to its Deep Space Network. However, any command will take a day to reach the spacecraft, followed by another day for confirmation of that command to beam back to Earth.
The historic Voyager spacecraft
NASA’s Voyager 1 and 2 spacecraft have achieved a long list of groundbreaking milestones. This is particularly impressive given the fact that, according to NASA, they have about 3 million times less memory than modern smartphones.
The two spacecraft were lifted into space in 1977. Their launch was timed to take advantage of an alignment of the outer planets that occurs once every 176 years. As they are still functioning, they are the longest-running missions in NASA’s history.
Voyager 1 performed a flyby of Jupiter and Saturn before heading out to interstellar space. The spacecraft was responsible for the ‘pale blue dot’ image taken at the suggestion of famous astrophysicist and science popularizer Carl Sagan. It is the most distant image we have of Earth.
Voyager 1 crossed the boundary into interstellar space in 2012, while Voyager 2 crossed the outer edge of our solar system in 2018. They are the only two spacecraft to have flown out of our star’s heliosphere.
NASA has said Voyager 1’s nuclear power source will keep the spacecraft working for another year or so. Voyager 2 hasn’t flown as far as Voyager 1, though it is still the second-most distant human-made object from Earth, having traveled 19.5 light-hours from our planet.