NASA’s Voyager 1 and Voyager 2 remain the longest-operating missions in the agency’s rich history. And in late 2026, Voyager 1 is expected to hit a remarkable milestone: it will become the first spacecraft to reach a distance of one light-day from Earth.

Already the first human-made craft to enter interstellar space—and the most distant object ever launched by humanity—Voyager 1 will reach this new record when radio signals, which travel at the speed of light, take a full 24 hours to reach it.

Figure 1. Spacecraft Voyager 1.

Approaching the Light-Day Mark

It has taken nearly half a century for Voyager 1 to reach this point. The spacecraft is currently around 15.7 billion miles (25.3 billion km) from Earth, and messages take about 23 hours, 32 minutes, and 35 seconds to arrive. In roughly a year, it will be about 16.1 billion miles (25.9 billion km) away—far enough for communication to require a full day. NASA estimates that the milestone will be reached around November 15, 2026.

At such extreme distances, communication becomes increasingly complex. NASA relies on its Deep Space Network to maintain contact, but every command will require a one-day trip out and another day for confirmation to return—a 48-hour round trip. Figure 1 shows Spacecraft Voyager 1.

A Legacy of Historic Firsts

Voyager 1 and Voyager 2, launched in 1977, were designed to take advantage of a rare planetary alignment occurring once every 176 years. Despite having computational power millions of times lower than a modern smartphone, both spacecraft have achieved unprecedented scientific milestones.

Voyager 1 conducted close flybys of Jupiter and Saturn before heading into interstellar space, and it captured the iconic “Pale Blue Dot” image, inspired by Carl Sagan [1]. It crossed into interstellar space in 2012, while Voyager 2 reached that boundary in 2018. They remain the only spacecraft to travel outside the heliosphere.

NASA expects Voyager 1 to operate for roughly another year before its nuclear power source is exhausted. Voyager 2, though not as far out, is currently 19.5 light-hours from Earth, making it the second-most distant spacecraft ever.

Reference:

1. https://interestingengineering.com/space/voyager-1-nasas-interstellar-spacecraft

Cite this article:

Keerthana S (2025), World’s Farthest Spacecraft Voyager 1 Nears Distance of One Light-Day from Earth, AnaTechMaz, pp.658