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Houston, We Have a Software Problem
An anonymous reader writes "The computer system that launches the Space Shuttle is an old, but important, computer system. It is built from mid 70's technology and features SSI chips like 7400's...which are getting hard to find. It has 64k of memory and no room to repair any software bugs. NASA started the CLCS project in 1996 which uses state of the art computer languages, OO methodologies, and hardware. Everything that you could actually hire people off the street for. However, NASA is in a budget crunch with the Space Station cost overruns. It is looking to trim costs to keep the Space Station going. There are stories about CLCS getting cancelled here and these guys say its already cancelled."
But I thought 64k should be enough for anybody...
I have nothing to allude to, and I am alluding to it.
Given todays hardware, why you can't just simulate the old system if finding parts for repair becomes a problem. You would just run your old software on the simulated machine.
At the beginning was at.
At some point it might be cheaper to give up on computers and just pilot the Shuttle by hand.
-- Ed Avis ed@membled.com
Certainly the 7400 series as a whole is still widespread and used in hobbyists kits, I'm not that old. Maybe the original 7400 is becoming obsolete, being replaced with the 74LS (low-power Schottkey) or CMOS chips? If then it shouldn't be too difficult to replace the TTL logic with CMOS logic, given a few adjustment levels in voltage, or they could use the TTL-logic and CMOS-logic in one compatible chips.
Of course, the 5400 series SSIs (small-scale integrated circuits) are preferred over the 7400s for industrial purposes, and as a plus they are completely backwards compatible. Why isn't NASA using those?
"The lesson to be learned is not to take the comments on slashdot too literally." --Vinnie Falco, BearShare
What?
"shuttle_launcher_0_1"
Excellent. That'll save a few dollars. What's the development status?
"1 - Planning, sir"
Ah.
(1) Print up 50,000 numbered authenticity certificates...
(2) Break down the old mainframes until you have roughly 50,000 pieces...
(3) Sell it on eBay (or other auction sites) as space memorabilia, mention that the computer the parts came from were responsible for guiding the Apollo missions to the moon, etc and so on... The machines are SO obsolete now that the only way they could pose a security risk is by sending them back in time...
(4) Profit!
(5) Buy a nice little beowulf cluster, hire 20 Linux geeks and feed each of them $50 in dew and pizza in exchange for setting up the system...
(6) Use remaining funds to pay the Russian space agency to have a little "airlock accident" for that Nsync guy...
Just because you can mod me down, doesn't mean you're right. Shoes for industry!
It's not like this is rocket science!
Oh, wait....
$0.02 (CDN)
Just what is the space station actually for?
The money spent on this (and the space shuttle) could be spent on real science and could get a thousand off-the-shelf spaceprobes to interesting places.
I suppose getting rid of Lance Bass would have made it worthwhile, but even that's not going to happen anymore (unless /.ers constribute to a paypal account for this purpose...)
roses are red
violets are blue
the Russians have satellite laser weapons
so why can't we too?
## W.Finlay McWalter ## http://www.mcwalter.org ##
I'm not one to replace things that are working fine, but as I understand it, newer designs could be a whole lot cheaper to operate. So I wonder if pouring more into the Space Shuttle program is the best thing to do.
I'm not saying "let's throw out the space shuttle" but it bothers me that there's apparently nothing in the works with a decent shot at replacing it any time soon. It seems the field of space exploration is becoming antiquated.
Hire John Carmack to do the job. He's into rocketry so he gets to learn more about the whole thing, you get a kickass system, and he may even do it for free.
The guy's so good he may do a better job than a bloated team of 400 contractors.
I was thinking this. Why don't they open some of the current code and some of the requirements they need to "the community".
Think of who space enthusiasts are and what a lot of them do; software and hardware development. In a budget crunch a good strategy would be to allow interested hobbyists to write some of the code, and then have NASA's boys peer review it.
-- The unsig...
From an article in the Sydney Morning Herald .
The software is built in a similar way - lots of internal checks, tell-me-thrice memory, soft-failure-bit-flip-correcting daemons etc. In this case, lives aren't at stake, but the people doing the programming are used to situations where they are.
Zoe Brain - Rocket Scientist
Might I suggest using FPGAs to emulate the hardware old system so the software doesn't have to be thrown out?
Assuming that circuit layouts are available for these old chips, it would be a piece of cake to emulate them in VHDL (a hardware description language) because they are comparatively simple to today's integrated circuits. Once the chip descriptions are written in VHDL, it would be relatively easy to 'port' the hardware over to a new FPGA if the old one dies or whatever. Then it would not be necessary to truly port or re-code any of the currently working code, and it would be much easier to fix bugs and extend it because you don't have the memory and speed limitations of the old system.
NASA falls under the classification of "independent agency" within the Federal government. The budget is hooked up with other agencies such as the Vetran's Administration if that tell you anything about how things are considered.
"player 4 hit player 1 with 0 stroms"
They obviously don't need very high performance, since it runs on 1970s hardware, but they do need high reliability and low development costs.
That means that they should be using a safe, secure high-level language. Something with a virtual machine might be a good idea so that it will be easy to adapt to new hardware platforms: you verify the virtual machine on the new machine and then have reasonable confidence that your code runs.
If they want something in widespread use, a home-built Java byte-code interpreter (not a JIT--they are too buggy) might be a reasonable choice--it's well specified and there are lots of people who know how to program it. They should probably avoid JNI like the plague and instead add new bytecodes for I/O and communications and verify them the same way that they do the virtual machine itself.. VLISP might be another good choice--or at least a source of ideas for how to implement a verified Java interpreter--DARPA already has paid for its development.
And they should hire someone who doesn't recommed COTS with C++, lest we see the next shuttle go up in flames again.
Replacing it can be harder. I used to work in newspaper publishing; the core editorial systems of one employer were old ATEX J11 systems with a proprietary, tightly integrated OS and application suite. Over time, various aspects of the system were offloaded to more modern systems (eg, PostScript output and integration with graphics from desktop systems had dedicated AIX systems, imagesetters driven by PostScript RIPs, dumb terminals run from dedicated I/O boards replaced with terminal emulators on the desktop).
Despite all this tweaking, the crufty old systems stayed in place. Why? Well, on each of these old boxes, we could support 25-30 journos and the systems just worked, grinding out newspapers day after day.
People kept talking about replacing them, not least because we had to train up operators and engineers on them every time new staff came in, parts were hard to come by (the standards-not-compatible SCSI and ethernet interfaces were picky about what they talked to, and the filesystem could only address 600 MB of disk per system), and they used huge amounts of power and floor space.
For the three years I worked there and in the three years hence no-one has been able to deliver an editorial system that just works. When vendors rolled their rigged demos in, they crash. The major vendors like CyberGraphics and ATEX couldn't point to successful implementations of their new systems producing a decent number of newspapers on the basis of more than one edition per day.
Would it have been nice to have a Unix or Windows based system? Sure. Reduced overheads and training burdens, able to buy the latest and greatest hardware, and so on. But no-one could actually deliver something that worked better than the crufty old J11 systems.
NASA are probably in a similar bind; it's a very familiar problem: old systems developed by tight, focused, skilled teams and developed over the years are very, very hard to replace.
I think it's important to realize that the Shuttle also represents the pinnacle of 1970's computing and that the whole of computing has changed significantly in the last ~25 years. In the 1970's, you didn't worry about things like GUIs (and all the "bloat" that they entail), TCP/IP stacks, extensive amounts of code to deal with the wide variety of hardware configuration, etc.
It's not so much an issue of bloated code as it is an attempt to cover all the bases. The shuttle software was designed with one purpose in mind -- get that shit-heap into orbit. You can't compare it to a modern Linux distro without invoking an apples-to-oranges counter-argument.
Furthermore, the launch of the shuttle isn't handled by a single onboard computer. It's handled by several. Please reference The Space Shuttle Operator's Manual for more on the systems aboard the shuttle. It's a general, non-technical overview, but a great reference, nonetheless.
You ask "where will it stop?" Here's a hint: it won't. And this same argument probably came up in the 1970's when they started writing the spec for the shuttle. The computer aboard the shuttle is more capable than Apollo for a mission profile that isn't significantly more difficult in any regard (generally speaking). Hell, the PDA you have sitting on your desktop right now has far more computing power than all the computers involved in the Apollo program put together, and it certainly doesn't do anything like putting men on the moon.
But again, it's all a matter of the scope of usage.
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I used to work with military electronics and found that the best gear was always from the 80s. The stuff from the 60s and 70s (yes, some of that is still in service) was too primitive. The 90s hardware was too complicated and suffered from unreliable software.
In the 80s the microcontroller technology was just good enough to embed a processor with 64k of ROM full of finely crafted code written by a single programmer and it always just worked, perfectly, every time.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
Hah! I don't think a 1541 is fast enough to handle that!
My Apple II, on the other hand, you just insert the disk and flip the power, and the NASASHUTTLE program comes up automatically, in 1/10th the time your C= disk drive loads it!
Of course, your version has better sound, and sprite graphics... but oh well.
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
Note that they are most likely using GNU software. Here is a list of the software development environments for these chips, and Here is the European Space Agency's web page for the tools and emulator.