On November 18, the Voyager 1 spacecraft will reach a distance of one light-day from Earth, becoming the farthest human-made object in history.
Reaching One Light-Day
At 5:16 a.m. EST on November 18, Voyager 1 will sit approximately 16.09 billion miles (25.9 billion kilometers) away from Earth, starlust.org reported. At that distance, a one-way signal takes a full 24 hours to reach the spacecraft, and any return message requires another full day. Light travels at about 186,282 miles per second, meaning the probe is now roughly 172 Astronomical Units distant. NASA has posted a countdown clock for November 18, 2026, at 5:16:07 a.m. EST.
NASA has organized a public participation event for November 17, inviting people to flash Morse code signals toward the sky using a flashlight, phone, or glow stick.
Surviving Interstellar Power Challenges
The milestone follows a tense 48-hour period in October when Voyager 1 temporarily stopped communicating with Earth on October 18 and 19. Space reported that the probe resolved the issue on its own before engineers could transmit a remote fix.
Mission managers at NASA’s Jet Propulsion Laboratory stated that the spacecraft appeared to enter a safe mode when a primary group of thrusters went offline, prompting backup units to kick in automatically. The communications pause occurred between October 18 and 20 when NASA’s Deep Space Network of three antennas did check-ins and the spacecraft did not respond before its signal reappeared on October 20.
The communications pause occurred shortly after the mission team completed a months-long operation to stretch the spacecraft’s diminishing power supply. Because the plutonium-fueled radioisotope thermoelectric generators lose about 4 watts of power each year, engineers executed a ‘Big Bang’ power swap that alternated primary heaters and an old 8-track tape recorder with low-power secondary options, keeping critical instruments like the Plasma Wave Subsystem operational.
Nearly Fifty Years of Exploration
Voyager 1 launched on September 5, 1977, on an extended tour of the outer solar system before crossing into interstellar space on August 25, 2012. Tom’s Hardware noted that the spacecraft is currently traveling at an estimated speed of 37,844.49 mph relative to the Sun, which makes it pretty fast, though the Parker Solar Probe holds the record at 394,736 mph.
It is heading in the direction of the star Gliese 445 in the constellation Ursa Minor. Mission managers estimate that the remaining power will allow the probe to continue gathering data into the 2030s.
Questions about Voyager 1 communication loss and speed
What caused the October communication loss on Voyager 1?
Engineers determined that a group of thrusters went offline and backup units automatically engaged, and the spacecraft appeared to enter a temporary safe mode while signal transmission paused for 48 hours.
How fast is Voyager 1 traveling?
The spacecraft is cruising through interstellar space at approximately 37,844 mph relative to the Sun, which amounts to about 0.0056 percent of the speed of light.
When was Voyager 1 launched?
The probe lifted off on September 5, 1977, initially designed for a five-year mission to observe Jupiter and Saturn before continuing past the heliosphere.
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