NASA’s Voyager 2 is back chatting it up after flight controllers corrected a mistake that had led to weeks of silence. Hurtling ever deeper into interstellar space billions of miles away, the 46-year-old spacecraft stopped communicating two weeks ago when a series of commands it received on July 21 mistakenly tilted its antenna away from Earth. On Wednesday, the probe’s Deep Space Network sent a new command to reorient its antenna, using its highest-powered transmitter at its giant radio dish antenna in Australia. The craft’s antenna needed to be shifted just two degrees.
The long-shot maneuver succeeded and at 12:29 a.m. On Friday, the agency said that Voyager 2, which has been operating for 46 years, began returning science and telemetry data to NASA. It also confirmed that it continued on its planned trajectory toward the edge of our solar system’s heliosphere and beyond.
How It Was Done
The spacecraft sends back signals daily, but they’re so feeble that it takes about 18 hours for them to reach us. The feeble signals are picked up by a worldwide array of giant radio antennas that make up NASA’s Deep Space Network, including its massive dish in Canberra, Australia. The feeble signal comprises just 160 bits per second, the equivalent of a digital watch’s clock ticking. But every so often, the Deep Space Network detects something more.
Those “flares” — or data bursts, as NASA calls them — contain essential information about the state of Voyager’s instruments and general health. Engineers at NASA’s Jet Propulsion Laboratory have kept tabs on both Voyagers since their launch in 1977 to explore the outer planets and serve as a beacon of humanity to the broader universe. The probes’ small plutonium nuclear reactors are nearly out of fuel now, but scientists have extended their lifespans by carefully controlling how they use the energy.
A series of commands sent to Voyager 2 on July 21 mistakenly caused its antenna to deflect two degrees from Earth, compromising its ability to send and receive information and jeopardizing the mission. The issue was expected to remain unresolved until the probe conducted its subsequent automatic reorientation on October 15, but scientists at JPL devised a plan to reestablish contact sooner. The space agency said that the team used Voyager’s highest-power transmitter to send an “interstellar shout” that righted the distant probe’s antenna orientation. The shout, which took about three hours to send, was based on a sequence of predetermined commands sent in the best conditions possible to align with the spacecraft’s antenna orientation. This method is riskier than the routine reorientation maneuvers the probe usually conducts. However, it is still the only way for scientists to control the spacecraft from a distance directly.