Probe Crash Due to Misdesigned Deceleration Sensor 374
squirrelhack writes "Seems as though the Genesis spacecraft was able to launch from earth, travel through space, avoid aliens, and cruise back into the atmosphere to be caught by stunt pilots waiting patiently with their helicopters. Alas, the brakes didn't work because a sensor was designed upside down.
It seems ... (Score:3, Insightful)
This stuff is EXPECTED (Score:5, Insightful)
It's NOT a waste. Research REQUIRES failure. SUCESS requires failure.
One step at a time, my fellow scientists and engineers. One step at a time.
Nice. But it's all good anyway. (Score:1, Insightful)
Ass-umptions (Score:3, Insightful)
Of course, they usually do get it right, in near-heroic fashion. But didn't it occur to anyone to try this out by, say, building a unit without the science part, bringing it along on a pre-scheduled Shuttle flight, and de-orbiting it? (IIRC, design and test pre-dated the Coulmbia accident). That way, they get a real re-entry at low (for NASA) cost.
Re:It seems ... (Score:5, Insightful)
Because no matter how much money you spend you can't buy perfect humans, and to err is human.
To correct error is engineering.
Once upon a time some 'wires' in my brain got crossed and I actually picked up a hot soldering iron from the wrong end. Have you ever had that experience where you realize you're about to do something terribly, terribly wrong, but the impulse has already been sent and you can't stop it?
I hate when that happens.
But I only did that once. Pain is a great teacher. One might almost come to the conclusion that that's what it's there for.
So the next probe will have the sensor absolutely correct and working. They'll have to come up with brand new ways to mess things up.
Just like I do.
KFG
Murphy's Law? (Score:4, Insightful)
The original lesson they learned was: That if a design allows for a part to be installed incorrectly, then that part will be installed incorrectly (eventually, or maybe even the first time).
Just a little bit of history repeating.
Alphaware ... (Score:5, Insightful)
These kind of mistakes make me wonder. WHY does NASA *HAVE* to re-design every freakin' thing on every freakin' mission from the ground up every freakin' time?
We're flying alpha-test spacecraft.
Re-usable modules anybody?? Heard of those? Standard designs? Sure, some parts are going to be different, namely the actual scientific instruments, but fer ghodssake an accelerometer?! WhyTF do we need to redesign that (its a weight, a spring and a switch, fer the love of pete) ?!!
-sigh-
Re:This stuff is EXPECTED (Score:5, Insightful)
We expect failures like "Hmm we didn't know there would be THAT much particulate matter in space, look at all those holes!", not "oops, got that backwards!!" or, "oops, forgot to convert to metric!"
"It's always the little things that get me, I always get a fscking decimal point wrong or something!" --Michael, Office Space
Not expected... tolerated (Score:5, Insightful)
What did we learn? Um... accelerometers only work in one direction... if you install them backwards, things don't happen right!
We tolerate mistakes if we have to make them, but this one (like all the recent Lockheed Martin screwups on work for NASA) appears to be stupidity.
It just shows that you gotta test (Score:5, Insightful)
Just like you should never write that code that cannot be tested (in the perfect world, every line would be executed during testing), you should never design a subassembly that cannot be tested.
It's a organizational attitude adjustment that's needed to put this into effect.
Symmetrical parts baaaaad (Score:5, Insightful)
Re:It seems ... (Score:5, Insightful)
I hope not. As the article says, the board was Broken As Designed -- the sensor was installed exactly as specified, but the specification was wrong.
Re:no such thing as... (Score:2, Insightful)
no such thing as cold, just the absence of heat
no such thing as dark, just the absence of light
guess what?
we english speaking humans have decided to call
and the absence of heat, 'cold' [reference.com]
the absence of light, 'dark' [reference.com]
and negative acceleration, 'deceleration' [reference.com]
You can look up what we call things here [dictionary.com]
If Murphy were alive, he'd be laughing ... (Score:2, Insightful)
Re:Why does Lockheed Martin continue to get NASA w (Score:1, Insightful)
Re:There is a bright side (Score:4, Insightful)
Re:This stuff is EXPECTED (Score:4, Insightful)
This is very true, but this type of failure should be deemed unacceptable by any reasonable person. This is the NASA equivalent of accidentally filling your car with diesel instead of gasoline. Or doing an 'rm -rf *' in your home directory. It's completely boneheaded and shouldn't be accepted by anyone.
I'm not a mean guy, and I don't hope that anyone at NASA loses their job over this, but I think a little bit of preventive ridicule is in order. I earned myself some nasty comments when I deleted a bunch of important (but thankfully, backed up) data with a braindead command, and I think I'm the better for it now.
Mistakes like this are easy to make... (Score:3, Insightful)
Usually, I find these kinds of mistake in my own work when someone else, who hasn't been tainted in the same way, points it out to me. I wonder why this kind of peer review didn't happen here?
Re:Murphy's Law? (Score:1, Insightful)
Re:not yet. (Score:3, Insightful)
1. What the hell are you talking about? Mars rotates just fine, and even has seasons.
how is this problem to be overcome when you must grow plants to sustain your existance?
2. Maybe the same way we do it on Earth? High powered, wide spectrum lamps.
Re:There is a bright side (Score:4, Insightful)
Poke-a-yoke or poka-yoke engineering anybody? (Score:3, Insightful)
One of the principles that has come about from continuous improvement, kanban, Toyota manufacturing is the idea of poke-a-yoke, or poka-yoke engineering.
The idea is, you design something so that it can only be used one way, so that errors in installation are eliminated. For example, if this switch/sensor/whatever needed to be installed from one side, you put a bump/notch on the opposite side that would prevent the part from being installed wrong.
For another example of this, if you have an N64 gaming system, take apart one of the controllers and look at the button design. Every button has slots that it fits in, so that you can only install a button in one location. There's no worrying about "Did I swap the A and B buttons?" because it's not possible.
Re:Poke-a-yoke or poka-yoke engineering anybody? (Score:3, Insightful)
My guess is that whoever designed that part had the head and tail of the probe itself backwards in their head.
Re:There is no "deceleration" (Score:3, Insightful)
Re:This stuff is EXPECTED (Score:3, Insightful)
It is trivial to do 30G. You don't even have to drop the thing. If you can't rent a centrifuge, build one - it will cost peanuts in a project of this scope. And with that controlled acceleration you can test, non-destructively, all you want.
What was missing there is the will to do things right.
Re:This stuff is EXPECTED (Score:2, Insightful)
Most types of errors are manageable in a large project, in the sense that you can design the process around them and try to prevent them. What is much more difficult is to prevent exactly this kind of stupid mistakes, for the very reason that nobody would think thay can be made.
Now why they happen so often in space projects and the like? Because the sheer size of the project. When filling 10000 tanks, one or two get filled with diesel instead of gasoline by mistake. Same with these projects, magnified by the fact that you have 10000 completely differen simple/obvious operations to do. And like i said, managers are helpless against them because you can't even guess where bad luck/stupidity is going to strike this time.
The big problem comes from the high cost of putting mass in orbit, which means low redundacy and reliance on smart design, which makes the perfect conditions for a stupid mistake like this to ruin the whole thing. It's not their _fault_, it's just the rules of the game. They weren't good enough this time...