NASA's distant Voyager 2 probe sent a "heartbeat" signal back to Earth after mission control accidentally lost contact, the US space agency said on Tuesday.

Launched in 1977 to explore the outer planets and serve as humanity's beacon to the wider universe, Voyager 2 is now more than 12.3 billion miles (19.9 billion kilometres) away from our planet, far beyond the solar system.

NASA's Jet Propulsion Laboratory (JPL) said in a recent update that a series of planned commands sent to Voyager 2 on 21 July "inadvertently caused the antenna to move two degrees away from Earth".

This left Voyager 2 unable to transmit data to mission control or receive commands. On 15 October, it was not expected to resolve this situation until it performed an automatic reorientation manoeuvre.

But on Tuesday, Voyager project manager Suzanne Dodd told AFP that in a last-ditch effort to re-establish contact sooner, the team enlisted the help of the Deep Space Network, an international array of giant radio antennas and several antennas in Earth orbit.

Surprisingly, "this was successful because we saw the 'heartbeat' signal coming from the spacecraft," he said. "So we know the spacecraft is alive and working. That lifted our spirits."

But while engineers can now see a heartbeat - in technical terms, the carrier wave associated with Voyager 2 - they cannot yet read the information signal that shapes the carrier wave that transmits all the data collected by the spacecraft.

"We are currently generating a new command to point the spacecraft's antenna at Earth," Dodd added, but said the likelihood of that working is only "low".

Still, given that 15 October is so far away, NASA will continue to try to send these commands.

GOLD PLATE

While JPL built and operated the Voyager spacecraft, these missions are now part of the NASA Heliophysical System Observatory.

Voyager 2 left the protective magnetic bubble provided by the Sun, called the heliosphere, in December 2018 and is now travelling in the space between stars.

Before leaving our solar system, it explored Jupiter and Saturn and became the first and so far only spacecraft to visit Uranus and Neptune.

Voyager 2's twin, Voyager 1, became mankind's first spacecraft to enter the interstellar medium in 2012 and is now some 15 billion miles from Earth.

Both Voyager spacecraft carry "Golden Records", 12-inch, gold-plated copper discs intended to convey the story of our world to extraterrestrials.

These discs contain a map of our solar system, a piece of uranium that acts as a radioactive clock, allowing receivers to learn the date of the spacecraft's launch, and symbolic instructions on how to play the record.

Selected for NASA by a committee chaired by legendary astronomer Carl Sagan, the content of the record includes coded images of life on Earth, as well as music and sounds that can be played using an included stylus.

For now, Voyagers continue to transmit scientific data, but their power banks are expected to run out after 2025. They will then continue to wander the Milky Way in silence, potentially forever.

 

Source: https://www.sciencealert.com/