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Submission + - Voyager 1 Is Communicating Well Again (scientificamerican.com)

Submitted by fahrbot-bot
fahrbot-bot writes: Scientific American is reporting that after [5] months of nonsensical transmissions from humanity’s most distant emissary, NASA’s iconic Voyager 1 spacecraft is finally communicating intelligibly with Earth again.

When the latest communications glitch occurred last fall, scientists could still send signals to the distant probe, and they could tell that the spacecraft was operating. But all they got from Voyager 1 was gibberish—what NASA described in December 2023 as “a repeating pattern of ones and zeros.” The team was able to trace the issue back to a part of the spacecraft’s computer system called the flight data subsystem, or FDS, and identified that a particular chip within that system had failed.

Mission personnel couldn’t repair the chip. They were, however, able to break the code held on the failed chip into pieces they could tuck into spare corners of the FDS’s memory, according to NASA. The first such fix was transmitted to Voyager 1 on April 18. With a total distance of 30 billion miles to cross from Earth to the spacecraft and back, the team had to wait nearly two full days for a response from the probe. But on April 20 NASA got confirmation that the initial fix worked. Additional commands to rewrite the rest of the FDS system’s lost code are scheduled for the coming weeks, according to the space agency, including commands that will restore the spacecraft’s ability to send home science data.

Also: Voyager 1 is sending data back to Earth for the first time in 5 months and NASA's Voyager 1 spacecraft finally phones home after 5 months of no contact

Submission + - Voyager 1 resumes sending information (nasa.gov)

Submitted by quonset
quonset writes: Just over two weeks ago, NASA figured out why its Voyager 1 spacecraft stopped sending useful data. They suspected corrupted memory in its flight data system (FDS) was the culprit. Today, for the first time since November, Voyager 1 is sending useful data about its health and the status of its onboard systems back to NASA. How did NASA accomplish this feat of long distance repair? They broke up the code into smaller pieces and redistributed them throughout the memory. From NASA:

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 ½ hours to reach Voyager 1, which is over 15 billion miles (24 billion kilometers) from Earth, and another 22 ½ 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.

Comment Re:The limits of science (Score 3, Insightful) 77

Certain topics do not lend themselves very well to the scientific method.

It's kind of hard to set up 100 universes, say, and run them through a few billion years. You can't do the experiment part.

Sometimes a hypothesis has potentially observable implications, even if a mad scientist can't reproduce everything in their lab.

Comment Re:Sounds like the current censoring of TikTok (Score 1) 53

by Ed Avis (#64407980) Attached to: Apple Removes WhatsApp, Threads and Telegram From China App Store
But American users, too, would keep their freedom to choose what apps to run (including TikTok) if they could just download their own software to the iPhone. It's only Apple's control-freakery that enables this interference by governments. In 2000 the idea of banning a piece of software would have seemed unenforceable. Even if you block its main download site, anyone could download a copy from somewhere else. We live in a much less free world now, and that's mainly thanks to the efforts of companies like Apple to strip users of control over their own computing devices.

Comment Re:Sounds like the current censoring of TikTok (Score 3, Insightful) 53

by Ed Avis (#64407666) Attached to: Apple Removes WhatsApp, Threads and Telegram From China App Store

Well, what's sauce for the goose is sauce for the gander. Apple has spent years building a tightly controlled walled garden and blocking any way for users to choose for themselves what software to run on their device. Only very recently (in the EU) have regulators started to push for greater openness. But of course, if Apple creates a locked-down device with total control, authoritarian governments will want to take that control for themselves -- and Apple, "obeying local laws" has no way to refuse those demands.

If your iPhone allowed you to download and install your own software, and not just as some special concession in certain markets but as the normal way it works, then it would be much harder for China or other countries to block particular apps.

And yes, there are certainly arguments in favour of a walled garden, for banking apps or for movie playback with DRM or for corporate paranoia about employee devices. And arguments against it too. It's not my intention to open a big discussion on those right now, just to note that Apple is getting a taste of its own medicine.

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