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."

Comments

the future?

[brondsem]

And what plans do they have to keep this from happening again in a decade?

Sorry if the article answers this, I can't get to it.

Why not simulate it?

[null-und-eins]

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.

Re:Why not simulate it?

[rodgerd]

Auditing the emulator and the host OS would be a problem - the code they've currently got has a very low rate of bugs, and has been extensively audited. NASA knows everything from the hardware up, exactly what the failure rate is and so forth.

Now, imagine you take modern commodity hardware (which changes periodically - look at how often Intel silently release new steppings of their CPUs). You're not going to have a guarantee of consistency there. You're going to have to boot an OS off it - and even the simplest RTOSes are still much, much bigger than the whole platform currently. Then you need an emulator. Then you need the system. And the only problem you've solved with all that work is the unavailablility of the old hardware - you still have a old machine language on a tiny platform which can't be easily extended for new functionality.

Re:Why not simulate it?

[WasterDave]

This is a very pertinent point that appears to have been lost on the initiators (and now burger flippers) of the replacement-launch-thingy project.

What they have, right there, is one spectacularly reliable piece of software. I suspect it's significantly more bug free than even the microcode in a modern processor, let alone the companion chips, bios, operating system, and virtual machine for some god awful p-code language (not that I'm naming names here).

The question that should have been asked is "how can we make a sustainable process for making extremely reliable control computers?". How to go about cutting custom silicon, tiny os's etc. How to save the happy tax payer hundreds of millions of dollars by reselling these services to people making nuclear power stations, heart pace makers etc. instead of going shopping for big sun boxes.

Oh well, reality strikes again.

Dave

Re:Why not simulate it?

[guybarr]

The HST was a PR thing anyway, for the same money they could of build several ground based telescopes that made the same nice pictures

Huh ? at what frequency regimes ? what about X-rays ? IR ? UV ?

besides, the atmosphere does distort image even for visible-light imagery. It is true that advances in image-fixing algorithms made, AFAIK, in the last decade attenuate the problem to a large degree, but, AFAIK, there was nothing like that in the seventies, and nothing is better than eliminating the problem altogether anyway.

perhaps today it will better to build bigger telescopes on earth than launch them (again, for the visible light regime. I very much doubt this is true for X, UV or IR imagery ... ) but I don't think this was even remotely true when the HST was designed and built.

saying such a large project, with published scientific results, is "just PR" with no references to back up your claim seems like slander to me.

I wouldn't be amazed if somebody told me they fitted the broken mirror on purpose so they could go and fix it with the shuttle...

I wouldn't be amazed by a lot of things, but I don't ususally go slandering hard-working people just based on what I suspect they are capable of doing.

The US space program and NASA deserve (and get) a lot of criticism, much of it is quite pejorative, much of it is technically sound. I haven't seen any such thing in your post, which is IMHO just nasty unbased negative PR .

Space-Station cost overruns

[wfmcwalter]

However, NASA is in a budget crunch with the Space Station cost overruns

Just what is the space station actually for?

• it's an expensive way to get second-rate microgravity
• it's a rotten, wobbly astronomy platform
• no-one is allowed to experiment with low-G sex (given the Russians' new found capitalistic streak, it's a wonder we've not seen any low-G porno yet - or maybe I'm just not in the loop on that)
• despite what the conspiracy-theory boys say, it'd make a crappy spy satellite and a worse orbital weapons platform
• there's only so many interesting things we can find out about how spiders make webs in freefall
• it's not even an efficient way for the US government to prop up the Russian government

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?

More shuttle development?

[timeOday]

The code in the Shuttle's launch system is old? The entire Space Shuttle is old. I'll bet a lot of slashdotters don't even remember the Columbia's maiden voyage.

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.

No money?

[ryochiji]

It's kind of sad how NASA's running out of money when the military gets so much money. Personally, a government that can keep a space shuttle fleet up to date and flying would give me a better sense of security than a government that's eager to go to war. But maybe that's just me.

use a verified virtual machine and compiler

[g4dget]

Trying to write such a system in C/C++ strikes me as rather stupid. It is extremely hard to write reliable software in C/C++. That may not matter much for desktop applications, but it matters when billions of dollars are in the balance.

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.

using GNU software, too

[g4dget]

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.