Caltech/NASA-JPL
It has 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.
However there is a renewed optimism among the many Voyager floor staff based mostly 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 attempt completely different sequences in its software program bundle. 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
Officers suspect a bit of corrupted reminiscence contained in the Flight Knowledge Subsystem (FDS), one in all three most important computer systems on the spacecraft, is the most definitely perpetrator for the interruption in regular communication. As a result of 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 mild journey time is about 22.5 hours.
The FDS collects science and engineering knowledge from the spacecraft’s sensors, then combines the knowledge right into a single knowledge bundle, which matches by a separate part known as the Telemetry Modulation Unit to beam it again to Earth by Voyager’s high-gain antenna.
Engineers are virtually totally sure the issue is within the FDS laptop. The communications techniques onboard Voyager 1 seem like functioning usually, and the spacecraft is sending a gradual radio tone again to Earth, however there is not any usable knowledge contained within the sign. This implies engineers know Voyager 1 is alive, however they haven’t any perception into what a part of the FDS reminiscence is inflicting the issue.
However Voyager 1 responded to the March 1 troubleshooting command with one thing completely different from what engineers have seen since this problem first appeared on November 14.
“The brand new sign was nonetheless not within the format utilized by Voyager 1 when the FDS is working correctly, so the staff wasn’t initially positive what to make of it,” NASA stated in an replace Wednesday. “However an engineer with the company’s Deep Area Community, which operates the radio antennas that talk with each Voyagers and different spacecraft touring to the Moon and past, was capable of decode the brand new sign and located that it incorporates a readout of all the 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 difficulty arose in November. This, they hope, will permit them to search out the foundation of the issue. However it would most likely take weeks or months for the Voyager staff to take the following step. They do not wish to trigger extra hurt.
“Utilizing that info to plan a possible resolution and try to put it into motion will take time,” NASA stated.
That 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 Solar, push in opposition to a so-called galactic wind, the particles that populate the void between the celebrities.
Engineers have stored Voyager 1 and its twin, Voyager 2, alive for greater than 46 years, overcoming technical issues which have doomed different house missions. Each probes face waning energy from their nuclear batteries, and there are issues about their thrusters getting older and gasoline strains changing into clogged, amongst different issues. However every time there’s a downside, floor groups have give you a trick to maintain the Voyagers going, usually referencing binders of fraying blueprints and engineering paperwork from the spacecraft’s design and building almost 50 years in the past.
Suzanne Dodd, NASA’s mission supervisor for Voyager 1 and its twin, Voyager 2, lately instructed Ars that engineers would wish to tug off their “largest miracle” to revive Voyager 1 to regular operations. Now, Voyager’s 1 voice from the sky has offered engineers with a clue that would assist them notice this miracle.
