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. When they subsequent anticipated to obtain information, 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. Along with its twin, Voyager 1, it’s humanity’s farthest-flung spacecraft that’s nonetheless accumulating information.
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 awful. It was a moment of panic, because we were 2 degrees off point, which was substantial,” says Dodd, the undertaking 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 might nonetheless obtain it, though 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 Space Network, a global system of large antennas managed by JPL. (Because of Voyager 2’s trajectory, one can solely talk with it by way of 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 have been fortunate—for a sign from Voyager 2 to ping them again.
The crew spent a sleepless night time ready. And then, reduction: It labored. Contact was restored on August 3 at 9:30 pm Pacific time. “We went from ‘Oh my gosh, this happened’ to ‘It’s wonderful, we’re back,’” says Linda Spilker, Voyager’s undertaking scientist at JPL.
Had the try failed, the crew would have solely had a single backup choice left: the onboard flight software program’s fault safety routine. Multiple fail-safes have 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 fitting course.
The Voyagers have been flying because the late Nineteen Seventies—they’re turning 46 in a pair weeks—and as Spilker factors out, “that was a two-week period with no science data, the longest period of time without it.” In the 2010s, they crossed the heliopause, the boundary between the photo voltaic wind and the interstellar wind. Since then, they’ve been taking information 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.
Still, that two-week interval with out contact didn’t interrupt the crew’s scientific work. “The Voyager science isn’t something you need to monitor constantly,” Calla Cofield, a JPL spokesperson, informed WIRED by way of electronic mail. “They’re studying this region of space over long distances, so a gap of a few weeks won’t hurt those studies.”