Hubble Repairs Hindered By Antiquated Computer Systems 193
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comes from the fact that it's been up there for nearly two decades, and therefore carries computer systems long outdated here on Earth.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."
Upgrade (Score:1, Insightful)
Re:Upgrade (Score:5, Insightful)
Re:Algorithms, control, what is the CPU for? (Score:0, Insightful)
Re:I feel their pain (Score:4, Insightful)
Voyager (Score:4, Insightful)
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."
It would be nice if the submitter would add a proposed remedy, like simply sending a service probe out to add some more RAM.
Oh, wait.
Well, I guess when they send a space probe out into the furthest reaches of the solar system, most scientists would expect that they will have to deal with whatever hardware was on board at the time of the launch for the duration of the mission.
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.
Re:Upgrade (Score:3, Insightful)
"...decade is enough time to figure that out and use exterior shielding instead of hardening. "
It's a fallacy to assume technology can solve every problem, or that solving it a specific way can be 'figured out'.
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.
Re:Upgrade (Score:3, Insightful)
Replacing an old 486 with one of these would require rewriting / compiling all the code running on them. Probably not enough of a performance gain in relation to the cost / risk of basically rewriting the code base from scratch.
"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.
Send a Repair and Replacement Team (Score:3, Insightful)
It's no news that Hubble is operating with technology that dates from the era of its launch.
If you want machines in space to use current tech, then you need to send people with uptodate hardware.
Hint, hint.
Re:Upgrade (Score:3, Insightful)
From reading the article, it didn't sound like they could even do upgrades, even if they wanted to (although I suppose they probably could salvage the mirror and build a new system around it). That actually surprises me a bit, since they knew this would be a long running mission and it is within range to be worked on. I know these days as a computer engineer, my bosses are always telling me to design for the future with upgrades in mind, but maybe that wasn't as big a priority back then (perhaps because each doubling of computer power is so much more massive now, and makes more of a difference than it did back then).
Re:Upgrade (Score:5, Insightful)
Re:"There really is no need to upgrade it." (Score:2, Insightful)
I doubt there's any NASA engineers lusting for a dual-core whoopie-doo. They just want their backup to come alive, after all these years.
The original deserves a medal, for service beyond, and a pension. Perhaps it could run for president.
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.
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?
Re:Voyager (Score:3, Insightful)
32k is a decent chunk to a decent embedded programmer.
The kids these days.
Re:Upgrade (Score:4, Insightful)
You do not need a significant increase in computational power. You need to increase reliability. If your OS goes bad, just re-read the whole thing from ROM. If a large portion of the program/OS is in rom, you dont need a lot of ram, just to store variables.
Just how smart do you think a microwave's CPU is?
Re:Upgrade (Score:4, Insightful)
Why use a heavy metal box to stop the cosmic rays or solar flare protons? They are both positively charged. Just put a positive charge around the computer box, and negative charge around a few "lightning rods" a few feet away and let magnetic forces do the rest. You don't have to stop the high energy particles, you just have to convince them to miss the few square inches of delicate electronics. Launch weight radiation shielding is something that NASA is going to have to tackle soon enough anyway if we ever want to leave our magnetosphere for more than about a week. Why not test it on a modern Hubble CPU, while keeping the remaining legacy chip as a back up?
Young man, in this forum we respect the laws of physics.
Go and find out how strong a magnetic field is required to deflect a proton with 1GeV of kinetic energy by 1 cm over a distance of, say, 2 m. Since you're obviously technically literate, that shouldn't be too difficult.
Hint: the answer is, "An impractically strong field is required, by a couple of orders of magnitude." Ever wondered why CERN use helium-cooled magnets which way tens of tons in their beamline?
Re:Upgrade (Score:1, Insightful)
yes, neutron radiation is a concern for satellites, and even for aircraft and electronics with high reliability requirements that operate at sea level. IIRC Boeing were one of the first to notice this happening in aircraft when they got random bit transitions in DRAM on aircraft.
As you point out, neutrons don't do much unless they hit a nucleus. But if they do happen to have a collision near electronics you typically get an alpha particle pinging off. Alpha particles are very easy to shield against, but these ones are getting created right in the middle of your silicon where it's too late to shield them. Being charged, the alpha particle is very likely to temporarily cause a FET to conduct or permanently change the charge stored in a DRAM cell, for example.
-Vern