NASA Switches Curiosity Rover To Backup Computer Following Glitch (extremetech.com)
NASA has switched its Curiosity rover over to its backup computer system after the main system started experiencing errors last month. "Many NASA spacecraft and surface missions have redundant systems built-in," reports ExtremeTech. "Once they've launched from Earth, there's no way to repair damage to critical systems, so it makes sense to double-up on the vital components. That includes Curiosity's computers, which were designed specifically for the harsh environment on Mars." From the report: The rover has a pair of identical brains running a 5-watt RAD750 CPU. This chip is part of the PowerPC 750 family, but it has been custom designed to survive high-radiation environments as you'd find on Mars or in deep space. These radiation-hardened CPUs cost $200,000 each, and NASA equipped the rover with two of them. Each computer also has 256 kB of EEPROM, 256 MB of DRAM, and 2 GB of flash memory. They run identical VxWorks real-time operating systems. When Curiosity landed on Mars in 2012, it used the "Side-A" computer. However, just a year later in 2013 (Sol 200), the computer failed due to corrupted memory. The rover got stuck in a bootloop, which prevented it from processing commands and drained the batteries. NASA executed a swap to Side-B so engineers could perform remote diagnostics on Side-A. In the following months, NASA confirmed that part of Side-A's memory was unusable and quarantined it. They kept Curiosity on Side-B, though. With Side-B experiencing problems preventing the rover from storing key science and engineering data, NASA switched Curiosity back to Side-A while it investigates the problem, which it can only do when the other computer is active. "NASA hasn't said how much of Side-A's RAM is bad, and it only had 256MB to start, but the team does intend to move Curiosity operations back to Side-B if possible," the report adds. "For now, the mission is functioning normally on Side-A."
it only had 256MB
What a strange use of the world `only`. 256MB is a lot, really a lot.
We could run our desktop computers with 256MB RAM at ease if we wanted to. As comparison: When windows 2000 was released (around 2000...) most computers only had around 64MB of memory, and that would already be a reasonable beefy computer. Windows 2000 liked a bit more, around 128, but would run on this 64MB just fine albeit a bit slow. And this same windows 2000 offered a desktop experience not much different from the (windows) desktops we are using today, including proper plug and play support, multimedia and whatever fancy you liked. When XP came a couple of years later, most people still hadn't updated to 256MB of memory.
Now, compare that to an embedded computer that does not have to waste any memory on fancy graphics, user interfaces and what more, and you will notice that 256MB is a lot. Really a lot. Try writing code to fill that up - a single human couldn't, even a whole team can't. Obviously it'll need some memory to store images etc, but this 2GB of flash is also a lot and comparable to what the first digital camera's came with..
And for those saying 'long time ago long time ago' - even today it's pretty common to write software that has no more than a single kilobyte of RAM memory available, for embedded purposes. With all the modern webcrap using gigabytes of memory for trivial tasks people seem to have lost the feeling for quantity. 256MB are more bits than i can count in my lifetime..
A glitch a day keeps the bugs away.
It will be used by NASA and the military and should be available in 2020.
Why is Snark Required?
And what is required to interact with your hardware. When older windows systems were out we were still using 8bpp. 16bpp and 32bpp each jumped the memory requirements up by a signficant margin. HDR jumped it again. OpenCL and JIT compiling jumped that up again. Modern hardware demands a lot more of modern software and modern software demands a lot more of hardware.
Having said that, it all depends on the realtime data input it has to process and its storage capacity. For what that rover is doing that is an impressively small amount of memory and storage. A few minutes of video footage could fill up its flash easily. When you consider how long it is between uploads to NASA it is quite impressive just how much work those little PPC boards in the rover can get done :)
Having said that, angry husbands armed with Illudium Q-36 Explosive Space Modulators are not something to be fucked with.
For "These radiation-hardened CPUs cost $200,000 each" read "Some fast-talking sales type managed to persuade a government employee to pay have the government pay $200,000 each for these things".
So somehow, the MMRTG that they installed on this beastie that was supposed to steadily provide over 2kwh of electricity for at least 14 years somehow magically decayed its plutonium fuel source in less than 6?
I think that this rover has a messed up idea of what "half life" means.
File under 'M' for 'Manic ranting'
Or "developing specialized semiconductors with extreme testing requirelents and a sales potential in the (at best) double digits is extremely expensive."
This is so cool! mars rover is like reversible underwear! Love the Side A/side B concept.
Much more than that they really take it to the extreme too! Imagine wearing side a until it's dirty, switching to side B, then DISINFECTING Side A and wearing Side A again! But that's not all! They are proceeding to disinfect side B so they can wear Side B again!
That's marvellous! It's mind blowing my awesome. Very soon we can perpetually wear the same underwear forever and just switch sides every now and than! Wow can you imagine? We might stand a chance to stop global warming given how much water is saved!
I guess nobody at NASA watches Star Trek...
GILORA: Starfleet code requires a second backup?
O'BRIEN: In case the first backup fails.
GILORA: What are the chances that both a primary system and its backup would fail at the same time?
O'BRIEN: It's very unlikely, but in a crunch I wouldn't like to be caught without a second backup.
#DeleteFacebook
$592.45 p.p.
https://eu.mouser.com/ProductDetail/VORAGO/VA10820-PQ128F0PCA?qs=AQlKX63v8RsaZ0n5FC8cxg==
Apple should have purchased VxWorks and made it into the new Mac OS, instead of being taken over by NeXT and taking on all that baggage. This was distinctly possible at the time when Apple was desperately seeking out a new OS to run on their PowerPC architecture.
If they had done so then today they could be crowing about MacOS-run machines trundling around on Mars. Instead they've got billions of land-apes using their software to share selfies.
Since creimer is likely behind all of his own drama, and he's never had sex with a woman, and he's only ever touched a penis with his hands, he is in fact, gay as a purse full of glitter!
No wonder why ram is failing. It takes a special kind of idiot to use DRAM in an application like this.
Excellent explanation, thanks!
"Every time I see an adult on a bicycle, I no longer despair for the future of the human race." - H. G. Wells