A Radio Signal From 15 Billion Miles Away
An aging spacecraftturned on a radio transmitter it hasn’t used in decades.
47-year-old Voyager 1is back in touch with NASA. A technical issue caused a days-long communicationsblackout with the historic mission, which is 15 billion miles away, ininterstellar space. While engineers work to understand what went wrong, Voyageris now using a radio transmitter it hadn’t used since 1981.
Launched in September1977, the NASA team has slowly turned off components to conserve power. Thishas allowed the aging spacecraft to send back science data from time to time.
The probe is thefarthest spacecraft from Earth, now operating beyond the heliosphere, which isthe sun’s bubble of magnetic fields and particles that extends well beyondPluto’s orbit. Now Voyager’s instruments can directly sample interstellarspace.
The new problem is oneof many the vehicle has faced in recent months, but the Voyager’s team keepsfinding creative solutions.
Occasionally, engineerscommand Voyager 1 to turn on some heaters to warm components that havesustained radiation damage. The heat can help reverse the damage. Messages arerelayed to Voyager from NASA’s Jet Propulsion Laboratory through the Deep SpaceNetwork. A system of radio antennas on Earth helps facilitate communicationswith Voyagers 1 and 2, and other spacecraft. When Voyager 1 sends data abouthow it is responding to the commands, it takes about 23 hours for a message totravel one way.
But when a recentcommand to the heater was sent, something triggered the spacecraft’s autonomousfault protection system. If the spacecraft draws more power than it should,this system shuts off non-essential systems. The team discovered the latestissue when it didn’t get the response signal.
Voyager 1 has beenusing its X-band radio transmitter for decades. Its second transmitter, calledthe S-band, hasn’t been used since 1981 because its signal is much fainter. Theteam believes the fault protection system shifted the spacecraft to the S-bandtransmitter, which uses less power.
The team won’t commandVoyager 1 to turn on the X-band transmitter until it figures out what happened,which could take weeks. They want to determine if there are any risks toturning on the X-band. But if the team can get the X-band working again, they mayget some data that reveals what happened.
In the meantime, theydon’t want to rely on the S-band for too long, because its signal is too weak.
You’ve got to give itto NASA, when they build something, they build it to last. Billions of milesfurther than a car would.
