NASA’s Voyager 1 is on the verge of making history, but the aging spacecraft is having a little trouble keeping in touch with home. Just weeks before becoming the first human-made object to travel a full light-day away from Earth, the probe briefly went silent, and NASA engineers are still working to understand why.
NASA lost contact with Voyager 1 in mid-October after engineers failed to detect its radio signal during two communication attempts 24 hours apart. The signal reappeared a day after the second attempt, but engineers are still investigating what caused the outage, according to NASA.
Launched in 1977, Voyager 1 has traveled an astonishing 16 billion miles (26 billion kilometers) from Earth, but NASA engineers aren’t ready to let it go just yet. In a bid to extend the spacecraft’s already remarkable journey through interstellar space, the team recently pulled off a crucial power-saving maneuver that could keep the aging probe operational longer than originally expected.
Signal loss
NASA relies on its Deep Space Network (DSN), an array of giant radio antennas spread across different parts of the world, to communicate with its interplanetary spacecraft. On October 18 and 19, DSN was unable to detect a radio signal from Voyager 1 during two scheduled attempts that were 24 hours apart.
Communication with the spacecraft resumed a day later on October 20, and the team has managed to stay in touch with Voyager 1 since then. NASA engineers are still investigating the reason behind the communication loss.
The team did, however, determine that one group of Voyager 1’s thrusters went offline during the communication loss, which prompted its backup thrusters to turn on automatically. The spacecraft is programmed to carry out this swap if its onboard computers detect a potential problem with the thrusters.
The automatic response places the spacecraft in a stable, safe configuration and pauses normal operations, which gives the team of engineers time to investigate the issue and take action.
“This is the first time we’ve seen the spacecraft do something like this, but we are also at a point in the mission where we have to expect the unexpected,” Kareem Badaruddin, Voyager mission manager at NASA’s Jet Propulsion Laboratory in Southern California, said in a statement. “We’re relieved to be back in contact with Voyager 1 and are eager to understand what happened.”
A light-day away
Voyager 1 is expected to reach one light-day away from Earth on November 18. At this point, the spacecraft will be 16.09 billion miles (25.89 billion kilometers) from Earth—or the distance that light can travel in one day. That means that it will take 24 hours for messages to reach Voyager 1 from Earth and vice versa.
“If you want to say ‘hello’ to Voyager, you send your message and then you go home and you wait two days before you finally get a response,” Suzanne Dodd, Voyager project manager at JPL, said in a statement.
The mission launched with 10 science instruments, some of which have been turned off to save power and keep the iconic probe alive. The twin Voyager probes are powered by heat from decaying plutonium, which is converted into electricity. Each year, the aging spacecraft loses about 4 watts of power.
NASA’s recent power-saving maneuver, called the “big bang,” switched off three devices on board Voyager 1 and swapped them with three lower-power alternatives. Without this recent effort, Voyager 1 would have had to turn off another instrument by summer 2027. Now, the spacecraft is traveling through interstellar space, collecting precious data on the region beyond the heliosphere, a bubble of particles and magnetic fields created by the Sun.
As it approaches one light-day away from Earth, Voyager 1 will not detect any changes to its environment. Instead, the milestone will offer a striking reminder of the spacecraft’s extraordinary journey and its ability to keep going through the unforgiving vastness of interstellar space.
