Caltech/NASA-JPL
It’s been 4 months since NASA’s Voyager 1 spacecraft despatched an intelligible sign again to Earth, and the issue has puzzled engineers tasked with supervising the probe exploring interstellar house.
But there’s a renewed optimism among the many Voyager floor workforce primarily based at NASA’s Jet Propulsion Laboratory in California. On March 1, engineers despatched a command as much as Voyager 1—greater than 15 billion miles (24 billion kilometers) away from Earth—to “gently immediate” one of many spacecraft’s computer systems to strive completely different sequences in its software program package deal. This was the newest step in NASA’s long-distance troubleshooting to attempt to isolate the reason for the issue stopping Voyager 1 from transmitting coherent telemetry knowledge.
Cracking the case
Officials suspect a piece of corrupted reminiscence contained in the Flight Data Subsystem (FDS), one in every of three essential computer systems on the spacecraft, is the probably offender for the interruption in regular communication. Because Voyager 1 is so far-off, it takes about 45 hours for engineers on the bottom to know the way the spacecraft reacted to their instructions—the one-way gentle journey time is about 22.5 hours.
The FDS collects science and engineering knowledge from the spacecraft’s sensors, then combines the knowledge into a single knowledge package deal, which matches via a separate element referred to as the Telemetry Modulation Unit to beam it again to Earth via Voyager’s high-gain antenna.
Engineers are nearly fully sure the issue is within the FDS pc. The communications programs onboard Voyager 1 look like functioning usually, and the spacecraft is sending a regular radio tone again to Earth, however there isn’t any usable knowledge contained within the sign. This means engineers know Voyager 1 is alive, however they have no perception into what a part of the FDS reminiscence is inflicting the issue.
But Voyager 1 responded to the March 1 troubleshooting command with one thing completely different from what engineers have seen since this subject first appeared on November 14.
“The new sign was nonetheless not within the format utilized by Voyager 1 when the FDS is working correctly, so the workforce wasn’t initially positive what to make of it,” NASA mentioned in an replace Wednesday. “But an engineer with the company’s Deep Space Network, which operates the radio antennas that talk with each Voyagers and different spacecraft touring to the Moon and past, was in a position to decode the brand new sign and located that it comprises a readout of the complete FDS reminiscence.”
Now, engineers are meticulously evaluating every little bit of code from the FDS reminiscence readout to the reminiscence readout Voyager 1 despatched again to Earth earlier than the problem arose in November. This, they hope, will permit them to seek out the basis of the issue. But it’ll in all probability take weeks or months for the Voyager workforce to take the subsequent step. They do not need to trigger extra hurt.
“Using that data to plan a potential answer and try to put it into motion will take time,” NASA mentioned.
This is maybe probably the most severe ailment the spacecraft has encountered since its launch in 1977. Voyager 1 flew by Jupiter and Saturn earlier than getting a kick from Saturn’s gravity to hurry into the outer photo voltaic system. In 2012, Voyager 1 entered interstellar house when it crossed the heliopause, the place the photo voltaic wind, the stream of particles emanating from the Sun, push towards a so-called galactic wind, the particles that populate the void between the celebs.
Engineers have stored Voyager 1 and its twin, Voyager 2, alive for greater than 46 years, overcoming technical issues that have doomed different house missions. Both probes face waning energy from their nuclear batteries, and there are considerations about their thrusters getting old and gasoline strains turning into clogged, amongst different issues. But every time there’s a downside, floor groups have provide you with a trick to maintain the Voyagers going, typically referencing binders of fraying blueprints and engineering paperwork from the spacecraft’s design and building practically 50 years in the past.
Suzanne Dodd, NASA’s undertaking supervisor for Voyager 1 and its twin, Voyager 2, lately advised Ars that engineers would wish to drag off their “largest miracle” to revive Voyager 1 to regular operations. Now, Voyager’s 1 voice from the sky has supplied engineers with a clue that could help them notice this miracle.