Antenna attitude toward Earth still being maintained, so there's that.

Humanity?s most distant space probe jeopardized by computer glitch
"It would be the biggest miracle if we get it back. We certainly haven't given up."
2/6/2024

https://arstechnica.com/space/2024/...omputer-glitch/

Excerpts:

State-of-the-art 50 years ago

The latest problem with Voyager 1 lies in the probe's Flight Data Subsystem (FDS), one of three computers on the spacecraft working alongside a command-and-control central computer and another device overseeing attitude control and pointing.

The FDS is responsible for collecting science and engineering data from the spacecraft's network of sensors and then combining the information into a single data package in binary code?a series of ones and zeros. A separate component called the Telemetry Modulation Unit actually sends the data package back to Earth through Voyager's 12-foot (3.7-meter) dish antenna.

In November, the data packages transmitted by Voyager 1 manifested a repeating pattern of ones and zeros as if it were stuck, according to NASA. Dodd said engineers at JPL have spent the better part of three months trying to diagnose the cause of the problem. She said the engineering team is "99.9 percent sure" the problem originated in the FDS, which appears to be having trouble "frame syncing" data.

So far, the ground team believes the most likely explanation for the problem is a bit of corrupted memory in the FDS. However, because of the computer hangup, engineers lack detailed data from Voyager 1 that might lead them to the root of the issue. "It's likely somewhere in the FDS memory," Dodd said. "A bit got flipped or corrupted. But without the telemetry, we can't see where that FDS memory corruption is."

When it was developed five decades ago, Voyager's Flight Data Subsystem was an innovation in computing. It was the first computer on a spacecraft to make use of volatile memory. Each Voyager spacecraft launched with two FDS computers, but Voyager 1's backup FDS failed in 1981, according to Dodd.

The only signal Voyager 1's Earthbound engineers have received since November is a carrier tone, which basically tells the team the spacecraft is still alive. There's no indication of any other major problems. Changes in the carrier signal's modulation indicate Voyager 1 is receiving commands uplinked from Earth.

"Unfortunately, we haven't cracked the nut yet, or solved the problem, or gotten any telemetry back," Dodd said.

In the next few weeks, Voyager's ground team plans to transmit commands for Voyager 1 to try to isolate where the suspected corrupted memory lies within the FDS computer. One of the ideas involves switching the computer to operate in different modes, such as the operating parameters the FDS used when Voyager 1 was flying by Jupiter and Saturn in 1979 and 1980. The hope among Voyager engineers is that the transition to different data modes might reveal what part of the FDS memory needs a correction.

This is a lot more complicated than it might seem on the surface. For one thing, the data modes engineers might command Voyager 1 into haven't been used for 40 years or more. Nobody has thought about doing this with Voyager's flight data computer for decades.

"Not to be morose, but a lot of Voyager people are dead," Dodd said. "So the people that built the spacecraft are not alive anymore. We do have a reasonably good set of documentation, but a lot of it is in paper, so you do this archaeology dig to get documents."

Imagine rummaging through a user's manual for an antique car. The book's weathered pages are probably fraying. That's not unlike what Voyager engineers, some of whom weren't alive when the mission launched, are experiencing now.

"We have sheets and sheets of schematics that are paper, that are all yellowed on the corners, and all signed in 1974," Dodd said. "They?re pinned up on the walls and people are looking at them. That's a whole story in itself, just how to get to the information you need to be able to talk about the commanding decisions or what the problem might be."

?It is difficult to command Voyager," Dodd said. "We don't have any type of simulator for this. We don't have any hardware simulator. We don't have any software simulator... There's no simulator with the FDS, no hardware where we can try it on the ground first before we send it. So that makes people more cautious, and it's a balance between getting commanding right and taking risks."

Managers are also aware of Voyager 1's age. It's operating on borrowed time. "So we don't want to spend forever deciding what we want to do," Dodd said. "Something else might fail. The thrusters might fail. We want to do the right thing, but we can't hem and haw over what the right thing is. We need to look at things methodically and logically, and make a decision and go for it."

When it comes time to send up more commands to try to save Voyager 1, operators at JPL will have to wait more than 45 hours to get a response. The spacecraft's vast distance and position in the southern sky require NASA to use the largest 230-foot (70-meter) antenna at a Deep Space Network tracking site in Australia, one of the network's most in-demand antennas.

https://cdn.arstechnica.net/wp-cont...704-800x624.jpg

FDS:

https://cdn.arstechnica.net/wp-cont.../voyagerfds.jpg

Antenna construction:

https://d2pn8kiwq2w21t.cloudfront.n...pegPIA21479.jpg

__________________
The other day I sat next to a woman who has a profound fear of flying. I wanted to comfort her, so I said, "Don't worry, we're not gonna' crash. Statistically, we got a better chance of being bitten by a shark." Then I showed her the scar on my elbow from a shark attack. I said, "I got this when my plane went down off of Florida." - Dennis Regan

NASA finds clue while solving Voyager 1's communication breakdown case
14 Mar 2024

https://www.space.com/voyager-1-com...ds-memory-issue

An outlier signal has brought ground control closer to decoding the troubling problem

The source of the issue appears to be one of Voyager 1's three onboard computers: The flight data subsystem (FDS). This computer, NASA says, is responsible for packaging science and engineering data before it's sent to Earth by the spacecraft's telemetry modulation unit.

The positive step towards solving communications issues between ground control and Voyager 1 came on March 3 when the Voyager mission team detected activity from one section of the FDS that was different from the rest of the computer?s garbled data stream.

Even the newly detected signal is still not in the correct format Voyager 1 should be using when FDS is functioning as designed, meaning the operating team was initially not quite sure what to make of it.

This changed, however, when an engineer at NASA's Deep Space Network, which is tasked with operating radio antennas that communicate with Voyager 1 and its interstellar sibling Voyager 2, as well as other NASA spacecraft closer to home, got a look at the code. The unnamed engineer was able to decode the outlier signal, discovering that it contained a readout of the FDS' entire memory.

Encoded with the FDS memory are performance instructions and code values that can change either if the spacecraft's status changes or if commanded to do so. Science and engineering data to be sent back to Earth are also locked up in the memory.

The team will now compare this new signal, which occurred because of a prompt, or "poke," from mission control, to data that was sent back to Earth just before Voyager 1 started spouting binary nonsense. Finding discrepancies between regular Voyager 1 data and this poke-prompted signal will help the crew hunt for the source of the issue.

__________________
The other day I sat next to a woman who has a profound fear of flying. I wanted to comfort her, so I said, "Don't worry, we're not gonna' crash. Statistically, we got a better chance of being bitten by a shark." Then I showed her the scar on my elbow from a shark attack. I said, "I got this when my plane went down off of Florida." - Dennis Regan

Amazing.

NASA optimistic about resolving Voyager 1 computer problem
March 27, 2024

https://spacenews.com/nasa-optimist...mputer-problem/

WASHINGTON - A NASA official says he is optimistic that a problem with the Voyager 1 spacecraft that has kept it from transmitting intelligible data for months can be resolved.

Speaking at a March 20 meeting of the National Academies Committee on Solar and Space Physics, Joseph Westlake, director of NASA's heliophysics division, said it appeared possible to fix the computer problem on the nearly 50-year-old spacecraft that has disrupted operations since last November.

"I feel like we're on a path now to resolution," he said. "They're on the right path and I think we're going to get to a point where Voyager 1 is going to continue, alive and kicking in space."

NASA announced March 13 progress in fixing the FDS when a command called a "poke" was transmitted to Voyager, and the spacecraft responded by sending back a readout of its memory. The agency said at the time it will compare that readout to one transmitted before the problem to help identify the issue.

Westlake said at the committee meeting that the problem appears to be a corrupted memory unit on the spacecraft. "It's a part failure on one of the memories and they're looking for a way to move a couple hundred words of software from one region to another in the flight computer," he said. A word is two bytes.

Previously:

Since November 2023, NASA's Voyager 1 spacecraft has been sending a steady radio signal to Earth, but the signal does not contain usable data. The source of the issue appears to be with one of three onboard computers, the flight data subsystem (FDS), which is responsible for packaging the science and engineering data before it's sent to Earth by the telemetry modulation unit.

On March 3, the Voyager mission team saw activity from one section of the FDS that differed from the rest of the computer's unreadable data stream. The new signal was still not in the format used by Voyager 1 when the FDS is working properly, so the team wasn't initially sure what to make of it. But an engineer with the agency's Deep Space Network, which operates the radio antennas that communicate with both Voyagers and other spacecraft traveling to the Moon and beyond, was able to decode the new signal and found that it contains a readout of the entire FDS memory.

__________________
The other day I sat next to a woman who has a profound fear of flying. I wanted to comfort her, so I said, "Don't worry, we're not gonna' crash. Statistically, we got a better chance of being bitten by a shark." Then I showed her the scar on my elbow from a shark attack. I said, "I got this when my plane went down off of Florida." - Dennis Regan

Looks like NASA may have a reached a successful fix on Voyager!

Link: https://www.usatoday.com/story/news...be/73414431007/


Earl

__________________
Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970

NASA's Voyager 1 Resumes Sending Engineering Updates to Earth
April 22, 2024

https://www.jpl.nasa.gov/news/nasas...pdates-to-earth

The team discovered that a single chip responsible for storing a portion of the FDS memory - including some of the FDS computer's software code - isn't working. The loss of that code rendered the science and engineering data unusable. Unable to repair the chip, the team decided to place the affected code elsewhere in the FDS memory. But no single location is large enough to hold the section of code in its entirety.

So they devised a plan to divide the affected code into sections and store those sections in different places in the FDS. To make this plan work, they also needed to adjust those code sections to ensure, for example, that they all still function as a whole. Any references to the location of that code in other parts of the FDS memory needed to be updated as well.

The team started by singling out the code responsible for packaging the spacecraft's engineering data. They sent it to its new location in the FDS memory on April 18. A radio signal takes about 22 - hours to reach Voyager 1, which is over 15 billion miles (24 billion kilometers) from Earth, and another 22 - hours for a signal to come back to Earth. When the mission flight team heard back from the spacecraft on April 20, they saw that the modification worked: For the first time in five months, they have been able to check the health and status of the spacecraft.

During the coming weeks, the team will relocate and adjust the other affected portions of the FDS software. These include the portions that will start returning science data.

Voyager 2 continues to operate normally.

The crew:

https://d2pn8kiwq2w21t.cloudfront.n...ger-copy-16.jpg

__________________
The other day I sat next to a woman who has a profound fear of flying. I wanted to comfort her, so I said, "Don't worry, we're not gonna' crash. Statistically, we got a better chance of being bitten by a shark." Then I showed her the scar on my elbow from a shark attack. I said, "I got this when my plane went down off of Florida." - Dennis Regan

Bunch of old farts........

Old mission, old experts.

How to Retain Institutional Knowledge When Employees Retire

https://www.iamagazine.com/strategi...mployees-retire

Every day, 10,000 baby boomers reach retirement age. Although many work well past their 65th birthday, most veteran employees take valuable company know-how with them when they finally walk out the door for the last time?leaving less-experienced employees struggling to fill their shoes.

__________________
The other day I sat next to a woman who has a profound fear of flying. I wanted to comfort her, so I said, "Don't worry, we're not gonna' crash. Statistically, we got a better chance of being bitten by a shark." Then I showed her the scar on my elbow from a shark attack. I said, "I got this when my plane went down off of Florida." - Dennis Regan

Heyyyy Nowww.

I'd bet most of us on this forum qual8fy for the "old fa4t" descriptor.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, AGITATION, CHAOS, TURMOIL, FIASCOS, AGGRAVATION, INSTIGATION, NUISANCE-ACTION, and HAVOC !

Or old shart.

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I love sanding.

Including myself. I'm 68.........