NASA’s Voyager 1 heads toward one light-day distance from earth

NASA’s Voyager 1 space vehicle testament go up a historical milepost nearly five decades after its launch, underscoring humanity’s longest-running deep-space mission.

By November 2026, Voyager 1 is expected to become the first human-made object to reach a distance of one light-day from Earth — about 16 billion miles away. At that range, radio signals travelling at the speed of light will take a full 24 hours to reach the spacecraft, and another 24 hours for a response.

“If I send a command and say, ‘good morning, Voyager 1,’ at 8 a.m. On a Monday, I will receive Voyager 1’s response on Wednesday morning at around 8 a.m.,” said Suzy Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory.

As Voyager 1 ventures deeper into interstellar space, communication has become increasingly challenging. The spacecraft transmits data at just 160 bits per second — comparable to early dial-up internet speeds.

“The distance from Earth means signals take much longer to arrive, and their strength diminishes along the way,” Dodd said. “It takes multiple antenna arrays to collect that signal.”

Because of the limited data rate and extreme distance, engineers receive only small amounts of information about the spacecraft’s condition, making rapid intervention impossible.

Despite its age, Voyager 1 was designed with a high degree of autonomy.

“If they get something going wrong, they can put themselves in a safe state so that they can wait until we're able to talk to the spacecraft and figure out what the problem is,” Dodd said.

To extend the mission, NASA has spent years shutting down non-essential instruments and systems to conserve dwindling power supplies.

Voyager 1 was launched in 1977, during a rare planetary alignment that occurs roughly once every 175 years. The configuration allowed the spacecraft to use gravitational “slingshot” manoeuvres to visit multiple outer planets, delivering unprecedented scientific results.

The probe flew past Jupiter and Saturn, discovering new moons, ring systems and dramatic atmospheric activity. It later headed north out of the ecliptic plane, setting it on a trajectory out of the solar system.

In August 2012, Voyager 1 became the first spacecraft to cross the heliopause — the boundary where the Sun’s influence gives way to interstellar space — marking a historic moment in space exploration.

As of August 2024, Voyager 1 was about 164.7 astronomical units from Earth, making it the most distant object ever built by humans. It continues to travel at roughly 38,000 miles per hour relative to the Sun.

Four instruments remain operational, allowing the spacecraft to study cosmic rays, magnetic fields and plasma waves in interstellar space.

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