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 area.
However there is 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 attempt completely different sequences in its software program bundle. This was the most recent step in NASA’s long-distance troubleshooting to attempt to isolate the reason for the issue stopping Voyager 1 from transmitting coherent telemetry information.
Cracking the case
Officers suspect a chunk of corrupted reminiscence contained in the Flight Information Subsystem (FDS), one among three predominant computer systems on the spacecraft, is the most probably offender for the interruption in regular communication. As a result of Voyager 1 is so distant, it takes about 45 hours for engineers on the bottom to understand how the spacecraft reacted to their instructions—the one-way mild journey time is about 22.5 hours.
The FDS collects science and engineering information from the spacecraft’s sensors, then combines the data right into a single information bundle, which fits 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 methods onboard Voyager 1 look like functioning usually, and the spacecraft is sending a gentle radio tone again to Earth, however there is no usable information contained within the sign. This implies engineers know Voyager 1 is alive, however they don’t have 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 situation 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 workforce wasn’t initially positive what to make of it,” NASA stated in an replace Wednesday. “However an engineer with the company’s Deep House Community, 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 accommodates a readout of your 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 difficulty arose in November. This, they hope, will permit them to search out the basis of the issue. However it should in all probability take weeks or months for the Voyager workforce to take the subsequent step. They do not wish to trigger extra hurt.
“Utilizing that data to plan a possible resolution and try to put it into motion will take time,” NASA stated.
That is maybe essentially 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 area 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 saved Voyager 1 and its twin, Voyager 2, alive for greater than 46 years, overcoming technical issues which have doomed different area missions. Each probes face waning energy from their nuclear batteries, and there are considerations about their thrusters ageing and gas traces turning into clogged, amongst different issues. However 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 development almost 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 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.