- Written by Jonathan Amos
- science correspondent
After months of spewing gibberish, the Voyager 1 probe is once again transmitting useful information to Earth, the US space agency announced.
The 46-year-old NASA spacecraft is the most distant celestial object known to humans.
In November, a computer failure prevented readable data from being returned, but engineers are currently fixing the issue.
For now, Voyager is only sending back health data about its onboard systems, but further work should bring scientific instruments back online.
“The Voyager 1 spacecraft is returning useful data regarding the health and status of its onboard engineering systems,” NASA said in a statement.
“The next step is to allow the spacecraft to send back scientific data.”
Voyager 1 was launched from Earth in 1977 to explore outer planets, but it continued on its way.
In 2012, it outgrew the bubble of gas emitted by the Sun (a region known as the heliosphere) and is now embedded in interstellar space, which contains gas, dust, and magnetic fields from other stars.
A damaged chip is believed to be the cause of the aging spacecraft's recent troubles.
This prevented Voyager's computers from accessing critical parts of the software code used to package information for transmission to Earth.
For a while, engineers were unable to get any sense from Voyager, even though they knew the spacecraft was still receiving commands and was otherwise operating normally. did not.
The issue was resolved by moving the affected code to a different location in the rover's computer memory.
Voyager 1 departed Earth on September 5, 1977, a few days after its sister spacecraft Voyager 2.
Their primary objective was to explore Jupiter, Saturn, Uranus, and Neptune, a mission they completed in 1989.
They were then steered into deep space, in the general direction of the center of our galaxy.
Its power comes from a radioisotope thermoelectric generator (RTG) that converts heat from decaying plutonium into electricity. The continuous decay process means that the generator produces slightly less power each year.
It's unclear how long Voyager will remain operational, but engineers have consistently come up with strategies to keep it operational for several more years.
Voyager 2 is a little behind the twins, moving a little slower.
It is just over 20 billion kilometers (13 billion miles) from Earth.
Despite both moving at speeds of more than 15 km/s (9 miles/s), they won't approach another star for tens of thousands of years.