Voyager 1, the spacecraft launched 47 years ago with its twin Voyager 2, and now hurtling at 38,000 mph (61,000 kph) away from our Solar System, as early as October experienced problems in its communications with Earth. NASA normally communicates with Voyager 1 and 2 via the “X-band” radio transmission, named for the specific frequency that it uses.
“On Oct. 16, the flight team sent a command to turn on one of the spacecraft’s heaters. While Voyager 1 should have had ample power to operate the heater, the command triggered the fault protection system. The team learned of the issue when the Deep Space Network couldn’t detect Voyager 1’s signal on Oct. 18,” reported the NASA blog.
Voyager 1 is now more than 15 billion miles away from Earth—the farthest any spacecraft has flown—and it takes 23 hours for it to receive an Earth command, and another 23 hours for its response to reach Earth via NASA’s Deep Space Network. This is why it took several days for the NASA engineers to figure out the issue. They realized that since the fault protection system had been triggered, Voyager 1 would have begun to transmit signals at a lower rate to conserve energy; they eventually found the signal.
Then, on Oct. 19, Voyager 1 stopped transmitting again! The flight team hypothesized that Voyager’s fault protection system had been triggered again, shutting down the X-band transmitter. What they discovered was amazing—Voyager 1 had switched to a second radio transmitter called the S-band. It uses less power, but Voyager 1 hadn’t used it since 1981—over 40 years ago!
