NASA Spacecraft Approaches Unprecedented One Light-Day Distance From Earth

The Voyager 1 space probe is approaching a distance of one light-day from Earth, marking the first time any human-made spacecraft has achieved this milestone.

Launched in September 1977, the spacecraft is now more than 26 billion kilometres away from home and travelling at approximately 61,000 kilometres per hour.

When Voyager 1 reaches the mark on Wednesday, November 18, radio signals travelling at the speed of light will need a full 24 hours to bridge the distance.

Project manager Suzanne Dodd said Voyager 1 acts as Earth's ambassador while providing a sense of wonder.

"It's a national treasure," she said. "Really extraordinary."

To celebrate the event, NASA is inviting the public to flash the mission designation VGR in Morse code using phones or flashlights after sunset on Tuesday, November 17.

The Times of India reported, citing the Associated Press, that the spacecraft would need around 18,000 years to cover a full light-year.

The mission was originally designed to study Jupiter and Saturn using a rare planetary alignment that occurs roughly once every 175 years.

That gravity assist technique allowed the spacecraft to explore uncharted regions before Voyager 1 crossed the heliopause into interstellar space in 2012.

The Hindu reported that controllers completed a power-conserving effort in September and briefly lost contact with the plutonium-powered spacecraft in October.

Engineers are still trying to figure out why communication was disrupted.

All this expertise has kept the mission running according to Dodd, who compared the probe to the little engine that could.

Controllers continue sending commands about once a week from the Jet Propulsion Laboratory in Pasadena, California.

Twin spacecraft Voyager 2 was launched two weeks before its sibling in 1977, but will not reach the one light-day mark until 2035.