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Hubble Repairs Hindered By Antiquated Computer Systems
Posted by
Soulskill
on Fri Oct 24, 2008 07:00 PM
from the you-should-see-the-sputnik-abacus dept.
from the you-should-see-the-sputnik-abacus dept.
Andrew Moseman writes "Part of the trouble NASA is encountering while fixing the Hubble Space Telescope comes from the fact that it's been up there for nearly two decades, and therefore carries computer systems long outdated here on Earth. 'One of the main computers that the Goddard team has been struggling with during the repair attempts runs on an Intel 486 chip, the height of 1989 technology.' Many of NASA's long-running missions rely on antiquated systems — the Voyager probes each have about 32k of memory — but the scientists say they can manage."
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Firehose:Hubble's 486, and other NASA antiquated computing. by Anonymous Coward
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Memory (Score:5, Funny)
Re:Memory (Score:4, Funny)
C:\>_
and for some reason the mouse doesn't move.
Parent
Hardly that antiquated (Score:5, Informative)
Maybe I'm just getting old, but a 486 doesn't seem all that big a deal to me. I mean it's not as if it's a completely different architecture to that in use today.
You know you are getting old... (Score:4, Funny)
...when you think Hubble is an astronomer.
I read the headline and thought there were complications during poor Edwin's double knee replacement.
Parent
Re:You know you are getting old... (Score:5, Funny)
Windows has detected a new piece of hardware:
Hubble Telescope
Would you like to try and find the driver on Windows Update?
Parent
Re:CPU Constrained? (Score:5, Insightful)
"PNG is somewhat better than TIFF last time I checked"
Most people learn at quite a young age that the word 'better' doesn't really mean anything on its own. Better at what? Better at supporting non-RGB colour spaces? Better at supporting RGB with more than 8bits per colour, or even floating point values? Storing multiple images in a single file? No, png supportings none of these things that tiff does. If you're creating computer graphics for UI's, websites etc, png is probably a better choice, as that's more what it's designed for, but there are many other uses for storing images outside of this scope that tiff fits much better than png. As far as compression's concerned, PNG supports DEFLATE, which existed before PNG did, and the same with TIFF and its supported LZW compression (not that there's anything stopping you compressing either with either).
To sum up: better at what?
Parent
I feel their pain (Score:5, Funny)
Re:I feel their pain (Score:4, Insightful)
Parent
"There really is no need to upgrade it." (Score:5, Insightful)
I love the end of the article:
"It's really reliable," she said. "There really is no need to upgrade it."
I wish more people understood that.
486 is not that old. (Score:5, Insightful)
This is a bullshit article. Unfortunately, that has become the norm for Popular Mechanics.
The Intel 486 is hardly some arcane CPU that's so old that nobody knows how to program it. Anybody who can write assembly for modern PCs can write assembly for the 486. And anybody who wants to write in a higher-level language can -- because all the 486 development tools are still easily available.
If you read the article, you'll find that it presents no evidence whatsoever for its assertion that the Hubble's use of a 486 makes it harder to repair. In fact, it reads more like, "The Hubble has a 486, and damn that seems outdated to me! Maybe that's why it's so hard to fix!" Really, that's about the level of the 'logical' argument that you'll find in the article.
Space rated. (Score:5, Informative)
Re:Upgrade (Score:5, Informative)
Parent
Re:Upgrade (Score:5, Informative)
Parent
Re:Upgrade (Score:5, Informative)
One of the reasons particles like neutrons are hard to stop is that they have no charge and don't react with the electromagnetic fields that bind matter together. You basically need a collision between the neutron and an atomic nucleus to stop it.
A particle that doesn't interact electromagnetically, however, is (if I'm not mistaken) less likely to interfere with electronic equipment. Which is not to say hard-to-stop radiation like neutron radiation does no damage at all, but I'd be curious to know whether it's a concern at all for satellites.
Parent
Re:Upgrade (Score:5, Insightful)
at 10,000 a pound to launch the shuttle, weight reduction is most important. sending up lead computer cases because hardening a processor is hard is not an option when plastic weighs several pounds less.
Also up until 3-4 years ago the hubble was going to be shut down in the next year or two and was only extended later. Unlike the mars rovers the hubble's life won't magical extend.
Parent
Re:Upgrade (Score:5, Insightful)
Why bother with heavy shielding when you can just make the transistors big enough to not be flippable by single stray particals? Thick shielding might prevent 99.999% of dangerous bit flipping radiation from getting through, but what about that last tiny bit, you're going to need extra circuitry to detect errors in the processors circuitry... and everything starts getting more complicated, and you end up back where you started. In space, simpler is better.
Parent
Re:Upgrade (Score:5, Interesting)
Actually, some sorts of shielding make things worse. Moderate amounts of shielding just end up providing targets for the really high energy particles, which releases a big cloud of moderate energy particles on impact. The secondary radiation is both more abundant and more likely to interact with the stuff on the inside, and so causes a bigger problem. For space applications, there are intermediate amounts of shielding that will actually *increase* the total dose. (This is the case for cosmic rays, not solar flares; the latter can be fairly effectively shielded against, but is frequently less of a concern.) If you're not willing to put *large* amounts of mass around the thing to be shielded, it's often impossible to improve things all that much.
Hardening often consists of simple changes that are nonetheless expensive because they involve changes to the whole production line -- things like rating all the transistors for a noticeably higher voltage, to reduce the likelihood of a radiation-induced latchup event. As chip voltages get lower, this gets harder. Other changes include things like using isotopically pure boron in your dopants -- boron comes in two common isotopes, 10B and 11B. 11B is relatively immune to cosmic radiation, but 10B will fision when hit -- releasing secondary ionizing particles that cause a much greater problem than the cosmic ray by itself would. So rad-hard chips end up made with (expensive) depleted boron.
Combine these, and you see why it's difficult to find a decent selection of rad-hard chips, and also why an up-to-date radiation hardened CPU can cost over $100k each -- and also why you nonetheless need them, and can't really substitute anything short of a few tons of shielding.
Parent
Re:Upgrade (Score:5, Informative)
What you want may well be impossible. There are no magical materials right now to do what you want. Cosmic rays in the range TeV can't be stopped with a box that can be affordably launched, much less fit into the satellite. It's easier to use chips that are designed to handle them.
NASA already has a backup computer, on which are two independent circuits to do the same thing. Side "B" that is on the Hubble right now is handling things right now, after side "A" quit working.
NASA is putting the last of their spare parts on the Hubble right now, after which, there are no more short of restarting production, which isn't going to happen affordably. They made a lot of replacement parts which were gradually used as there were servicing missions.
Parent
Re:Upgrade (Score:5, Funny)
Can't they just remodulate the shield harmonics or reverse the polarity of the neutron flow or something?
Parent
Re:Upgrade (Score:5, Funny)
Good God man, if we do that, we could turn all matter into doesn't matter, then nobody will give a fuck.
Parent
As If.... (Score:5, Funny)
It's common knowledge 486s (and their variants) were pulled from the classified wreckage at Roswell NM earlier last century. Trust me, they've had plenty of time to work with those babies.
Glad I could help clarify that.
Parent
Re:Upgrade (Score:5, Insightful)
Parent
Re:Upgrade (Score:5, Insightful)
Parent
Re:Upgrade (Score:4, Interesting)
It takes several years to develop a radiation hardened version of circuits, in addition to being very expensive. About the most modern such processor is based on the PowerPC 750, aka Apple's G3.
Also, as far as I understand it, processors using smaller processes are much more difficult to harden, which significantly limits modernization.
Parent
Re:Upgrade (Score:5, Interesting)
Parent