When Suzanne Dodd’s crew transmitted a routine command to Voyager 2 on July 21, the unthinkable occurred: They unintentionally despatched the fallacious model, which pointed the interstellar probe’s antenna barely away from Earth. Once they subsequent anticipated to obtain knowledge, they heard nothing in any respect. The small error nearly made humanity lose its reference to the favored spacecraft, which is now 12.4 billion miles from residence. Together with its twin, Voyager 1, it’s humanity’s farthest-flung spacecraft that’s nonetheless gathering knowledge.
Right here’s what occurred: Dodd’s crew at NASA’s Jet Propulsion Laboratory had truly noticed the error within the command and corrected it—however then mistakenly despatched out the flawed model. “It felt terrible. It was a second of panic, as a result of we had been 2 levels off level, which was substantial,” says Dodd, the mission supervisor of the Voyager interstellar mission.
The crew settled on an answer: Blast a “shout” command within the probe’s course, telling it to regulate the antenna again towards Earth. If the sign was robust sufficient, the craft may nonetheless obtain it, regardless that its antenna was offset.
On the morning of August 2, they despatched the highest-power sign they might, utilizing the high-elevation, 70-meter, 100-kilowatt S-band transmitter on the communication station in Canberra, Australia. The station is a part of NASA’s Deep House Community, a world system of big antennas managed by JPL. (Due to Voyager 2’s trajectory, one can solely talk with it through telescopes in Earth’s southern hemisphere.)
There was no assure of success, and it could take 37 hours to see if the answer had labored: The time it could take for his or her sign to ping the craft, after which—in the event that they had been fortunate—for a sign from Voyager 2 to ping them again.
The crew spent a sleepless night time ready. After which, reduction: It labored. Contact was restored on August 3 at 9:30 pm Pacific time. “We went from ‘Oh my gosh, this occurred’ to ‘It’s great, we’re again,’” says Linda Spilker, Voyager’s mission scientist at JPL.
Had the try failed, the crew would have solely had a single backup possibility left: the onboard flight software program’s fault safety routine. A number of fail-safes had been programmed into the Voyagers to mechanically take actions to take care of circumstances that might hurt the mission. The subsequent routine was anticipated to kick in in mid-October. If it labored, it could have generated an accurate pointing command, hopefully adjusting the antenna in the proper course.
The Voyagers have been flying for the reason that late Seventies—they’re turning 46 in a pair weeks—and as Spilker factors out, “that was a two-week interval with no science knowledge, the longest time frame with out it.” Within the 2010s, they crossed the heliopause, the boundary between the photo voltaic wind and the interstellar wind. Since then, they’ve been taking knowledge on the sting of the heliosphere, the protecting bubble of particles and magnetic fields generated by the solar, which interacts in unknown methods with the interstellar medium.
Nonetheless, that two-week interval with out contact didn’t interrupt the crew’s scientific work. “The Voyager science isn’t one thing it’s good to monitor continually,” Calla Cofield, a JPL spokesperson, instructed WIRED through e-mail. “They’re learning this area of house over lengthy distances, so a niche of some weeks gained’t damage these research.”