Nasa's Deep Space Network (DSN) has detected a carrier signal from Voyager 2, confirming that the spacecraft has not been lost in space and remains operational.
The space agency had lost all communications with Voyager 2 after accidentally sending a wrong command on July 21, which caused the spacecraft's antenna to point two degrees away from Earth and lose contact with mission control.
The spacecraft's antenna is expected to point towards Earth in mid-October, when communications with mission control will be able to resume. Until then, Nasa will attempt to send a command to Voyager 2 to correct the position of its antenna.
Nasa was able to pick up a 'heartbeat' signal from Voyager 2 during a regular scan of the sky. This type of signal is not strong enough to transmit data, but it confirms that the spacecraft continues on its expected trajectory.
"We enlisted the help of the DSN and Radio Science groups to help to see if we could hear a signal from Voyager 2," said Suzanne Dodd, Voyager's project manager at Nasa's Jet Propulsion Laboratory in Pasadena, California.
"This was successful in that we see the 'heartbeat' signal from the spacecraft. So, we know the spacecraft is alive and operating. This buoyed our spirits."
Voyager-2 / Nasa
Image credit: Nasa
The DSN is an international array of massive radio antennas that allows Nasa to communicate with missions across the cosmos. It consists of three giant dishes located in the US, Spain and Australia. This positioning ensures that almost any spacecraft with a line of sight to Earth can communicate with at least one of the facilities at any time.
Given that Voyager 2 is almost 20 billion kilometres (more than 12 billion miles) away, the signal sent from the DSN would have taken around 18 hours to reach the craft.
Voyager 2 originally departed Earth in 1977 on a mission to study the outer planets Jupiter, Saturn, Uranus and Neptune. It is the only spacecraft to have visited the latter two.
The probe is programmed to reset its orientation multiple times each year to keep its antenna pointing at Earth. The next reset is due on 15 October, which Nasa says "should enable communication to resume".
In the meantime, Nasa operators are still firing signals to correct the antenna's direction, in the hope that it will be picked up by the spacecraft.
"We are now generating a new command to attempt to point the spacecraft antenna toward Earth," Dodd said. "There is a low probability that this will work."
Voyager 1 and 2 / NASA, JPL-Caltech
Image credit: reuters
Voyager 2 and its twin Voyager 1 are the only spacecraft ever to operate outside the heliosphere, the protective bubble of particles and magnetic fields generated by the Sun.
Between them, the spacecraft have made numerous discoveries, including the first active extraterrestrial volcanoes on Jupiter's moon Io, hints of a subsurface ocean on Jupiter's moon Europa, an Earth-like atmosphere on Saturn's moon Titan and icy geysers on Neptune's moon Triton.
This is not the first time that the probes have faced technical challenges. In 2020, all communication with Voyager 2 was cut for seven months as it underwent repairs and upgrades.
