NEWS: Why is the Hubble Telescope So Hard to Fix?

GEEK: Why is the Hubble Telescope So Hard to Fix?

Some of you might have read or heard in the news that the Hubble Telescope is in need of repair again. NASA has capped spending on other projects or eliminated projects entirely in order to go through with these repairs.

This will be the fourth mission to repair the Hubble. It was originally planned for October of this year, but unfortunately due to some equipment failing, it has been pushed back to 2009 so that the equipment that failed can also be replaced.

This got my interest piqued about why it is so difficult to actually perform repairs to the Hubble Telescope. So being the geek that I am, I started asking questions and reading as much as I could.

The first person I asked was my Physics professor. His answer to me was, "It launched in 1990, think about it." I did think about it. It didn't make any sense until I actually started reading about it.

It launched in 1990. That means that systems were being built prior to 1990.

The Hubble was basically built in the late 1970's through the 1980's. To the non-geek, this probably still doesn't mean anything, but to a true tech/computer geek, this means a lot.

The Hubble, at this current moment, is running an Intel 486 Microprocessor.

Still doesn't make sense? Maybe this will help:



That right there is state of the art 1990 technology at it's finest.

Still not making any sense? Intel 486 Technology is pre-Pentium technology. If you are reading this on a computer that runs Windows XP, your computer has a bigger chip in it than the Hubble does. I have personally worked on computers that utilize Windows 95/98 and have a bigger processor than the Hubble.

So when that sleazy computer salesman says, "This is better than what NASA has," he really isn't lying in a sense.

Okay. Still not making sense? This should definitely clear it up:

The Hubble can't even play WoW? What has the world come to?

So why does this matter? Mostly because the engineers, technicians and scientists aren't trained on 25 to 30-year-old technology. The people that initially designed the systems are either, well, dead, or long retired from NASA. Computers and microchips have come a long way in that time, so NASA workers basically have to be backwards trained in order to work on the Hubble.

The age of the equipment is not a problem that just plagues the Hubble, the Voyager 1 and Voyager 2 missions have similar issues as well.

The Hubble techs are trained in an area of NASA known as the Vehicle Electrical System Test (VEST) clean room.

Not only do the techs that maintain the system have to be trained, the astronauts that physically service it have to be trained also. They have to be trained for the rigors of space travel, high gravity, weightlessness, muscle atrophy, eating in space, and how to work on your grandmother's computer.

The life expectancy of the Hubble was 15 years; NASA is now headed into the 19th year. It has worked well beyond what the designers thought it would, and it's worth repairing, as the James Web Space Telescope (JWST) project has been delayed to 2013 due to budget constraints and engineering difficulty.The next administration may cut the funding entirely due to the economy.

The Hubble has helped scientists understand the universe more than any other tool that NASA has developed. Understanding those simple things, like the age of the universe, quasars, dark energy and sending back the deepest telescopic views of the universe ever seen before.

The Hubble is hard to fix, basically because it's old-school technology and it wasn't initially meant to last this long. Colleges and universities don't have classes on 486 processors anymore, not in the age of quad-core processor, or the eight core Sony Cell processor your Playstation 3 has, or the three-core Xenon processor your Xbox has. NASA needs to train its employees on how to work on equipment this old. Training takes time, and costs money.

With our economy the way it is, many other projects have been delayed or canceled in order to ensure the Hubble gets the attention it needs. While some argue that the Hubble is not worth it, I am pretty impressed with the mileage and the information we have received from the Hubble.

You can see most of the pictures yourself HERE.

NASA's budget has been cut repeatedly over the years, many projects have been mothballed, and some candidates talk about freezing "unnecessary" spending altogether, which includes NASA's budget. The effects of this would be devastating to the ongoing projects they have at the moment. The missions that require constant funding would become useless overnight. Billions of dollars, manhours and major discoveries would be lost in one fell swoop.

Space missions aren't considered special anymore, and are constantly overlooked with everything else going on. I remember the days when we stopped class to watch a shuttle launch. These days, people barely know the shuttles even exist. I don't think NASA gets the recognition it deserves and I hope it doesn't become lost with the next administration, as it has with the current one.

DevilsReject wants to be an astronaut when he grows up.

Great article... this is something about the Hubble that just hadn't occurred to me. It makes the fact that it's still (just about) operating all the more impressive. I hope the upcoming repairs go well, because I love this wheezy old telescope.

I know it. I worked on a research reactor whose safety and detection systems were built with magnetic core logic. Worked flawlessly; but we couldn't get anyone to train on it, because it wasn't career-friendly. We wound up closing it down.

It isn't quite as drastic a difference as you suggest.

Anyone who could write code for a quad core processor could code for a 486. To some degree the fewer bells and whistles might make the process easier.

The kid down the street who just started building his own PCs could easily deal with grandma's 486. To my somewhat vague recollection, he'd have less problems with a 486 than with a 1st gen Pentium (no need to pair the SIMMS). Of course, I sometimes forget some of my classic computer facts, but I seem to recall DIMMS coming into play a bit later. Perhaps I'm wrong on that.

At my old job I sometimes had to tinker with some antiquated proprietary microcomputer systems. It didn't tend to be the nightmare you're suggesting. Aside from the dust.

Wasn't the Hubble rescued not too long ago by school-aged kids basically petiioning to keep it going?

I remember discussing this a number of years ago. It's a problem that's plagued NASA for quite a while. Part of the problem, apart from Hubble actually being designed in the 70s, is that NASA can't even use the newest computer technologies when they're designing something.

The computer systems used by NASA have to undergo rigorous testing before they can actually go into space and the rest. Something about life-critical systems. This certification takes a long time, and as a result, NASA is always using technology that is long obsolete by computer standards.

I recall a number of stories of them shopping eBay for ancient computer parts they couldn't find anywhere.

I'm not sure I always disagree with the concept. Take the Motorola 68000 microprocessor, for example. The damned thing has been in use for 30 years, in a wide variety of applications. It works. You can't play the fanciest new video games on it, but it will do a lot of the guidance, navigation, a control functions you need, and it does it reliably without using a shitload of power.

It also has the advantage of there still being people who know how to program it.

You'd be surprised at the chips that are still being used in embedded systems. They're obsolete for use in personal computers, but they're perfect for applications where you absolutely cannot accept system failure.

Oh i won't argue that. The fundamentals of the coding are the same, but what NASA often runs into is employees not wanting to take part in a project that isn't cutting edge technology

The kid down the street is going to probably get intrigued by the 486 technology, and then move on to the newer technology and strive to learn more and more, becoming bored with the easier and older technology. Once into the industry, taking steps backwards to do your job isn't really appealing. At least in my opinion. Although i would be damn happy to work on a 486 for NASA.

I get to tinker with older computers all the time. The technology is sound, the problem is when you put an end user on it, but that's with all computer systems. I've also had to tinker with relay logic to get it working properly again on some of the machines i have had to work on. Ladder Logic and relay logic, while similar, are not the same, and there are times that the relay logic was so basic, i actually got stumped because it was too easy.

The technology itself isn't a nightmare, having to backwards train the technicians is costly though. It does take time, and it does consume some funds.

Sick pretty much rattled off the whole concept though. NASA will never use the newest technology, they will use the most stable technology due to the long-term and stress requirements on the systems.

Nice job, man... Interesting stuff.

Essentially. Unfortunately, that doesn't affect how difficult it is to actually go and perform the repairs.

The biggest of which is that it takes several astronauts to do it.

There is a petition floating around to preserve it also. I can't find the link, i know i read it somewhere, but NASA plans on recovering it once the new Telescope is launched and bringing it back to mother earth.

I *think* there is a petition to have it donated to the Smithsonian so that people can observe it and it is remembered for what it has done and how much it has done.

That's just one facet of it.

Here's another one to roll over in your head: Every single step of repair on a space mission has to be plotted in advance down to the most excrutiating detail. It's like a home repair project where if you realize you grabbed the wrong gauge hexnut, the nearest Home Depot is in Zimbabwe.

What's more, the tools you're using are all bizarely cuterbalanced, or counterrotating, so that when you use them in zero gravity, you have less to worry about pushing yourself away. Or spinning in the opposite direction yourself, rather than turning the screw. Because even though you anchored yourself to the thing you're working on first thing, bouncing around while you run the repairs slows you down.

Speaking of slow, let's talk about putting on a spacesuit. Something that would be a 30 minute job around the house is an all day job at the slow, deliberate pace you move in a big, clumsy spacesuit. Just getting the thing on is an ordeal. The depressurizing and repressurizing at both sides of the mission eat hours of your day.

Lastly,while you're out there in your clumsy spacesuit with your cracked out space tools, for everyone's sake, please make sure not to drop anything. Really. Not a single thing. Because once it's out of arm's reach, congrats, you've just created one more bit of space junk. Most space junk is harmless, sure, because space is so freaking BIG, even just the orbital zone around the earth. Odds are you'll never see it again and neither will anyone else. But... well... just in case. Put it this way: On one of the shuttle missions, the front windshield of the shuttle got cracked in orbit through the first two panes of bulletproof 'glass'. Later inspection showed that the object the shuttle had hit was a fleck of paint.

A fleck of paint.

Yeah.

Turns out when something going twenty times the speed of sound hits something else going the same speed in the opposite diretion, it doesn't need to be big to do serious damage. If you dropped a bolt or a hexnut and encountered it on a later mission going the other way, it would probably tear clean through the shuttle. Sure, the odds are crazy low, but lets just stick with good habits. Pocket every bit you pull off the thing during repairs before it can float away.

^^^ i started to get into the difficulties of actually working in space in the article originally, it would have been a huuuuuuge article, so i cut most of that out.

that was a good read

Now try tinkering in space.

This is only true on a surface level. Yes, you could write the code, compile it with an appropriate compiler, and it would run.

But given the lean resources on these things, the NASA programming on that machine is probably highly optimized for the specific chipset that it's running on. That means breaking open the code in assembler and coding for individual bit registrars and other ridiculous, hardcore programming shit that people just don't do very often anymore.

You could just compile and run, yeah. But it won't work as well.

Also it's in fucking space, which makes everything more difficult.

Good article, man.

The code was probably written in assembly in the first place*, you know. And the x86 architecture is more or less backward compatible; if you can write assembly for a brand-new quad core, it won't take long to figure out how to write for a 486.

And there are still people who can write assembly. Embedded systems programmers come to mind.

And this damned thread was in my head all day, making me think what assembly I'd have to write to turn my TI-89 into a guidance computer to take me to the moon.

But it's true, there are few people who can do that sort of thing any more. We've had a whole generation now that's learned to program without any sort of resource restraints. Computation too slow? Fuck it...get a bigger processor!

No one much cares about writing things efficiently these days. Except high-level crackers. It's a shame, but minimalist computing isn't much in vogue, because the focus is on adding new features as quickly as possible and getting the software out the door and making money.

Now, I remember when I was a kid, we had the 640 kB barrier!



*Although I know the Space Shuttle doesn't; it uses a specialized language, HAL/S, on IBM AP-101 computers.

Can't they just add some of those new $5 sensors onto it?

A friend of my Mom's stayed with Mom a few years ago. A friend of hers was on a shuttle mission to fix/upgrade the Hubble. The dude was a Veterinary Surgeon. A man used to having his hands inside of many species. It almost makes sense.

You don't. you sell me the TI-89 and take my TI-30Xa on partial trade and use that for your guidance system, i am in dire need of programmables.

Hand written equations are getting old. fast.

come on dude. It's not like we're doing something simple here, like automating the railroads.

Nah, you don't want mine. It's at least 8 years old; they made a lot of updates since then. Probably ones that could get me to Mars, even.

Writing equations by hand builds character, makes you actually learn what you're doing, and allows you to check your work if something blows up. Or I just don't want to give up my calculator.

But in all seriousness, if you're going to be using it a lot, go hungry and skimp on gas for a bit, and get a TI-83 or 84. Go on Amazon and get a used one for much less, even. I have the TI-89 because I'm a mathematician and I needed the symbolic math capability, but if that's not something you need, don't bother spending the extra money.

Even with the 83 or 84, you're probably looking at more computing power than was used on the Apollo missions.

Actually, about 15 times faster, and 100 times the memory; I think the Apollo guidance computer ran at about 1 MHz and had 24K of memory. State of the art.

The 486 (with 2MB of RAM) was a replacement (done in 1999) for the original computer. The original used a DF-224 with 64KB of RAM. The first servicing mission (in 1994) added a 386 coprocessor to help, but the DF-224 remained the main one.

Producing any computer for use in space missions is extremely expensive and takes a while, due to the conditions (e.g. high radiation) and high reliability required. As far as I know, the best system currently available is the RAD750. It's roughly equivalent to a G3 (at 100-133MHz) with up to 128MB of RAM. The RAD6000 (its predecessor) is very popular, with over 100 things currently using it (from satellites to the Spirit Mars rover launched in 2004), and has a max clock speed of 33MHz.

Mac lovers may be amused to hear that both the RAD750 and RAD6000 are POWER architecture processors, which is the style Apple used until they switched to Intel

Speaking of missing tools in space...

The dialog that didn't happen, on account of HAM radio enthusiasts being able to tune into NASA communications.

Some day, some where on a distant planet that tool bag will land and the movie, "The Gods Must Be Crazy." will take place for real.