For the final 5 months, it appeared very attainable {that a} 46-year-old dialog had lastly reached its finish.
Since its launch from Kennedy Area Heart on Sept. 5, 1977, NASA’s Voyager 1 spacecraft has diligently despatched common updates to Earth on the well being of its programs and information collected from its onboard devices.
However in November, the craft went quiet.
Voyager 1 is now some 15 billion miles away from Earth. Someplace within the chilly interstellar house between our solar and the closest stars, its flight information system stopped speaking with the a part of the probe that permits it to ship indicators again to Earth. Engineers on the Jet Propulsion Laboratory in La Cañada Flintridge might inform that Voyager 1 was getting its messages, however nothing was coming again.
“We’re to the purpose the place the {hardware} is beginning to age,” mentioned Linda Spilker, the challenge scientist for the Voyager mission. “It’s like engaged on an vintage automobile, from 15 billion miles away.”
Week after week, engineers despatched troubleshooting instructions to the spacecraft, every time patiently ready the 45 hours it takes to get a response right here on Earth — 22.5 hours touring on the velocity of sunshine to achieve the probe, and 22.5 hours again.
By March, the staff had found out {that a} reminiscence chip that saved a few of the flight information system’s software program code had failed, turning the craft’s outgoing communications into gibberish.
A protracted-distance restore wasn’t attainable. There wasn’t sufficient house wherever within the system to shift the code in its entirety. So after manually reviewing the code line by line, engineers broke it up and tucked the items into the obtainable slots of reminiscence.
They despatched a command to Voyager on Thursday. Within the early morning hours Saturday, the staff gathered round a convention desk at JPL: laptops open, espresso and containers of doughnuts in attain.
At 6:41 a.m., information from the craft confirmed up on their screens. The repair had labored.
“We went from very quiet and simply ready patiently to cheers and high-fives and massive smiles and sighs of aid,” Spilker mentioned. “I’m very joyful to as soon as once more have a significant dialog with Voyager 1.”
Voyager 1 is one in all two equivalent house probes. Voyager 2, launched two weeks earlier than Voyager 1, is now about 13 billion miles from Earth, the 2 crafts’ trajectories having diverged someplace round Saturn. (Voyager 2 continued its weekly communications uninterrupted throughout Voyager 1’s outage.)
They’re the farthest-flung human-made objects within the universe, having traveled farther from their house planet than the rest this species has constructed. The duty of preserving communications going grows tougher with every passing day. Each 24 hours, Voyager 1 travels 912,000 miles farther away from us. As that distance grows, the sign turns into slower and weaker.
When the probe visited Jupiter in 1979, it was sending again information at a price of 115.2 kilobits per second, Spilker mentioned. At this time, 45 years and greater than 14 billion miles later, information come again at a price of 40 bits per second.
The staff is cautiously optimistic that the probes will keep in touch for 3 extra years, lengthy sufficient to have a good time the mission’s fiftieth anniversary in 2027, Spilker mentioned. They may conceivably final till the 2030s.
The dialog can’t final endlessly. Microscopic bits of silica preserve clogging up the thrusters that preserve the probes’ antennas pointed towards Earth, which might finish communications. The ability is working low. Finally, the day will come when each Voyagers cease transmitting information to Earth, and the primary a part of their mission ends.
However on the day every craft goes quiet, they start a brand new period, one that would doubtlessly final far longer. Every probe is provided with a metallic album cowl containing a Golden Report, a gold-plated copper disk inscribed with sounds and pictures meant to explain the species that constructed the Voyagers and the planet they got here from.
Erosion in house is negligible; the pictures may very well be readable for an additional billion years or extra. Ought to every other clever life kind encounter one of many Voyager probes and have a way of retrieving the information from the report, they may on the very least have an opportunity to determine who despatched them — even when our species is by that point lengthy gone.
