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.
There is a bright side (Score:5, Interesting)
The primary limitation is the maximum weight we can get to the Earth/Moon Lagrange points. Once at the L-points, the cargo pretty much travels one gravity slingshot to the next with nearly no fuel expenditure. This could be a massive boon for sending Interplanetary mission cargo, especially when staging manned missions!
The only down side is that the IPSHwy is simply too slow for manned travel. Not too bad of a tradeoff, however, when you consider the amount of mass that can be more easily staged at Mars in advance! It's certainly reasonable that we could have a complete microsat network at Mars before a human ever sets foot there. Services that could be provided include:
- Mars GPS system
- Deep Space Network [wikipedia.org] Uplink
- Satellite Radio Communicators for landing teams
- Detailed mapping and emergency surveillance of problem areas
In short, we could have a complete technological infrastructure on Mars before we risk anyone's life going there. It wouldn't have to be like the moon mission. We could go to stay.
Re:There is a bright side (Score:3, Funny)
Well, you can, anyway. "Batman, off the island!"
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:3, Funny)
Re:There is a bright side (Score:3, Informative)
The primary limitation is the maximum weight we can get to the Earth/Moon Lagrange points. Once at the L-points, the cargo pretty much travels one gravity slingshot to the next with nearly no fuel expenditure.
If anyone is interested, I believe this is also known as a soft orbit transfer. IIRC, this technique was inveneted to rescue a mission that had suffered a pretty catastrophic failure.
Re:There is a bright side (Score:3, Funny)
I'd prefer we get to the interstellar gravitational-thermal equivalence zones and travel via Alderson jump points.
Re:There is a bright side (Score:5, Interesting)
Fill a large container with radioactive waste, send it up the elevator, tow / launch it to the nearest lagrange point, and send it down the superhighway.
When it gets to it's exit, thrusters fire and it flies directly into the sun. No more radioactive waste.
Re:There is a bright side (Score:5, Funny)
Re:There is a bright side (Score:3, Funny)
Hey, look on the bright side! At least the Sun doesn't supernova so soon now, with all the junk we are chucking in!
Re:There is a bright side (Score:4, Interesting)
I wonder though if that technique of solidly encasing nuclear waste posted not to long ago might work as a means of jettisoning waste into the Sun?
Re:There is a bright side (Score:3, Interesting)
Two Things... (Score:4, Informative)
1) Some plastics are designed to decompose.
2) Most plastics that aren't designed to decompose... don't. Instead they undergo weathering by the elements and 'vanish' as they are ground down by sun, wind, rain, and snow into plastic dust which then remains in the environment [eurocbc.org] for hundreds/thousands of years. This is a worldwide problem. [bbc.co.uk]
This flies against all the enviromentalists saying they will stay here forever
It flies against nothing. Just because something is too small for you to see does not mean that it is 'gone'. Weathering does not equal decomposition. Choice quote from the BBC article [bbc.co.uk]: "...this study suggests that practically everything really is made of plastic these days - even the oceans."
Re:There is a bright side (Score:5, Informative)
Seriously, a solar or even a high earth orbit is fine for storing waste indefintely. Don't need to waste delta vee directing it into a star. Stuff is heavy.
Re:There is a bright side (Score:4, Insightful)
Re:There is a bright side (Score:5, Funny)
What about Carbon-14?
Re:There is a bright side (Score:4, Insightful)
Re:There is a bright side (Score:3, Funny)
Re:There is a bright side (Score:5, Funny)
So now when I travel, instead of the airline sending my luggage to another city, it can end up anywhere in the *solar system*. Yeah, that's just what we need!
It seems ... (Score:3, Insightful)
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
Re:It seems ... (Score:5, Interesting)
Mistakes happen, as you say. As is commonly accepted my many software developers, software has bugs.
The parent notes that mistakes happen in even the most expensive projects. I think it's more likely to happen in complex (and therefore expensive) projects.
Re:It seems ... (Score:5, Funny)
Yeah. Every time I go to Slashdot.
Re:It seems ... (Score:3, Funny)
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.
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.
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
Re:This stuff is EXPECTED (Score:3, Interesting)
The carburator wouldn't work, it would be removed and replaced, and nobody would think anything untoward had happened.
The problem here is that there's no way to test something like this on, say, a half-dozen demo models before it goes out the door. Every single thing has to work right the first time, with
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.
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.
Re:Not expected... tolerated (Score:3, Interesting)
Yes. But the real lesson here is that when you are designing something of this sort, don't design it so that it only works one way round. Make sure that it works in both directions, with the output only enabled for the correct direction...
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.
Well it turned out to be a win win situation ... (Score:5, Funny)
OT: your sig (Score:2)
-Ab
To err is human... (Score:5, Funny)
Obligatory bugs bunny quote (Score:5, Funny)
I was trying for comedy (Score:2, Funny)
When told about its demise, Peter Gabriel responded with "So?"
Re:I was trying for comedy (Score:5, Funny)
KHAAAAANNNNN!!!!
Enough! (Score:5, Funny)
Upside Down? (Score:3, Funny)
Blame game... (Score:5, Interesting)
Jonah Hex
Re:Blame game... (Score:2)
Re:Blame game... (Score:2)
Why does Lockheed Martin continue to get NASA work (Score:5, Interesting)
Thought we still use Imperial for SPACE WORK (Mars Climate Orbiter IIRC?)
Recently dropped a sat because it wasn't bolted down when they moved it.
Now this.
Can I get like a billion dollars to fail repeatedly? PLEASE?
References (Score:5, Informative)
For them dropping the NOAA sat:
http://www.space.com/spacenews/businessmond
(first link I found)
Climate Orbiter:
http://www.space.com/news/mco_report-b_
Re:References (Score:3, Funny)
http://www.spaceref.com/news/viewsr.html?pid=10
This one has the pictures that are enough to make anyone wince and shake their head sadly.
Re:References (Score:3, Funny)
If my kids weren't sleeping, I'd be laughing loud enough for them to hear me in San Antone.
I can even see where the bolts were missing. :) I can just picture some long-haired stoner with a ratchet giggling his nuts off while he's taking the bolts out. "They'll never figure this out. Heee heee! They won't even check! Heeee Heeeee! Put snakes in my cup, will they, hahahahahahahahaha"
That one has practical joke written all over it. :) And those two guys in the white suits with the shower caps, they're
Congress, NASA, JPL also to blame (Score:3, Informative)
When the final report comes out, we will presumably learn why t
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.
sensor was designed upside down (Score:5, Funny)
Hmm (Score:4, Funny)
The mission's Mishap Investigation Board will continue to investigate the problem.
Oh, suuuure. MIB stands for "Mishap Investigation Board" now, huh? We're on to you, you governemnt spooks!
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.
Better than breaks on takeoff? (Score:2)
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-
You Forgot (Score:3, Funny)
Of course, said sticker would have shown up on the invoice to NASA as "sund.explns" and carried a price of $42,000.
Re:Alphaware ... (Score:4, Informative)
I hate to tell you this, but NASA HAS been using proven parts in spacecraft, there is a strong push for COTS (Commercial Off-The-Shelf) Hardware, it's much cheaper than designing every op-amp from scratch. But this COTS stuff has to be beyond military spec, it has to be rad-hard, withstand severe thermal and vibrational stresses, etc. It's easy to make a reusable op-amp or logic gate in a desktop computer, but for a satellite they have to be MUCH more rugged.
Regarding this accelerometer, not sure why it had to be different, but like I said before, it definitely needed to be rad-hard, endure strong vibrational and thermal extremes, and still function flawlessly upon re-entry. That's not easy to design, and there are 100000000 things to go wrong, one of which is that it's installed backward.
Now as to the reason they don't re-use spacecraft designs is that every craft has different operating parameters. Some are very far from Sun and Earth, and need higher-gain antennas (ie, parabolic dishes that can retract) and RTG's (solar panels become inefficient beyond Jupiter). Some operate close to Earth orbit and use solar panels and smaller antennas. Some will never re-enter earth, some will burn up on re-entry when their use is finished, and some need to survive re-entry intact. Some craft close to the sun (eg SOHO) need special rad-hard thermally-shielding designs. The inclusion or exclusion of each of these items will drastically change the structure of the craft.
So basically, each mission is so different that it's very unfeasible to come up with a reusable 'strawman' design from which to start all NASA craft. And this is just considering operating environment, power, and communications. That's not even including the scientific instruments, all of which need specialized heating or cooling or shielding or vibrational-isolation requirements, etc.
Like a spring (Score:2)
Doesn't that mean that the parachutes should have deployed on take off? heh....
Hmmm... (Score:5, Funny)
They should have known! (Score:5, Funny)
3... 2... 1... *PFOOF*
Re:They should have known! (Score:3)
But I suspect you may have just been trying to be funny?
Happened to me too.... (Score:2)
Caused me many a lost mission and endless hours of frustration that night. These guys got lucky...
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.
Re:It just shows that you gotta test (Score:2, Funny)
Symmetrical parts baaaaad (Score:5, Insightful)
Learning (Score:2)
Redundant logic (Score:5, Interesting)
But recently it looks like they kind of dropped this concept, at least partially. Probably as a cost-cutting measure. The success of the whole mission now depends on the reliability of several single components, like the sensor in discussion.
BTW, did you know that a Mars Rover has a single CPU that carries out all the computation? I found this puzzling. Today, you add redundance in every piece of equipment - even in web blades.
Re:Redundant logic (Score:2)
That's what faster, cheaper, better is all about. Higher-risk, lower-cost missions. They're also considered a way to give younger people experience in running a mission (since not everybody can run, say, Cassini, and you'd like to have a way for them to build experience first), which means careers are getting torpedoed by not having the funding to do something completely redundant.
My
mundane detail (Score:2)
Michael B.
Satellite Design Group
Lockheed Martin
Very much like the origins of Murphy's Law! (Score:2, Informative)
read about the whole story: http://en.wikipedia.org/wiki/Murphy's_law [wikipedia.org]
(note that the sensors were wired backwards as opposed to installed backwards)
If Murphy were alive, he'd be laughing ... (Score:2, Insightful)
odd headlines (Score:3, Funny)
Saucer From Space Crashes In Utah Desert!
My first thought was, "what bullshit!". But then I realized it was 100% true. (Well, okay, it was kind of an obese saucer shape.)
the ultimate Murphy (Score:2)
here's the link to the story: http://www.improb.com/airchives/paperair/volume9/
(remove the fnords... er.. slashdot inserted spaces)
There is no "deceleration" (Score:3, Informative)
Re:There is no "deceleration" (Score:3, Insightful)
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?
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.
Yeah (Score:4, Informative)
I read the same story here [yahoo.com] earlier today, and it also says that it was installed backwards.
Re:wtf (Score:5, Informative)
The sensors, which are estimated to be less than an inch (2.5 centimetres) wide, were apparently installed in a circuit board in the wrong orientation - rotated 180 from the correct direction. But the problem stemmed not from the installation but the design, by Lockheed Martin, based in Bethesda, Maryland.
Re:wtf (Score:2, Interesting)
I caught that too. What I don't understand is what was wrong with the design. Is the crash investigation team saying, "Yeah, the sensors were designed wrong, but, huh, check it out, they were installed b
Re:wtf (Score:2)
No, not quite. They're saying that the manufacturer designed them to be installed backwards on the circuit board. i.e. The assembly guys did everything right (it probably only fit one way), but Lockheed-Martin screwed the pooch.
Re:wtf (Score:4, Informative)
So the failure was in design, not installation. The net result still being it ended up backwards.
At least that's what I'm reading.
Re:wtf (Score:4, Funny)
Re:wtf (Score:3, Funny)
Implementation error: design was correct, but the implementor reversed the polarity of the switch.
Remember Murphy's law is not 'Whatever can go wrong will.' it is 'Whenever there are two possible ways to implement something and one of them will result in a catastropic result, it can be certian that someone will configure things that way.' (paraphrased.)
In this case the report is that there were two possible ways that th
Re:wtf (Score:2)
Re:wtf (Score:2)
Then, shouldn't the switch have been triggered by *acceleration* and fired the chute right after takeoff?
Re:wtf (Score:2)
Re:wtf (Score:4, Interesting)
For some reason, I'm reminded of the origins of Murphy's Law [improb.com]. I recall that too was the result of some sensors being installed backwards...
Re:wtf (Score:2)
Crappy readers can't understand that the sensor was installed in an upside-down position because the sensor was designed upside-down.
Was the sensor upside down? Yes.
Was the sensor upside down because it was installed wrong? No.
Was the sensor upside down because it was designed to be upside-down when installed according to the instructions? Yes.
So, it was installed upside-down, but it
Re:Mirror? (Score:2, Informative)
17:18 15 October 04
NewScientist.com news service
Sensors to detect deceleration on NASA's Genesis space capsule were installed correctly but had been designed upside down, resulting in the failure to deploy the capsule's parachutes. The design flaw is the prime suspect for why the capsule, carrying precious solar wind ions, crashed in Utah on 8 September, according to a NASA investigation board.
The sensors were a key element in a domino-like series of event
Re:no such thing as... (Score:2)
Come on! Practicality people!
Re:no such thing as... (Score:2)
Re:no such thing as... (Score:5, Informative)
From Dictionary.com:
3 entries found for deceleration.
decelerate Audio pronunciation of "deceleration" ( P ) Pronunciation Key (d-sl-rt)
v. decelerated, decelerating, decelerates
v. tr.
1. To decrease the velocity of.
2. To slow down the rate of advancement of: measures intended to decelerate the arms buildup.
v. intr.
To decrease in velocity.
Re:no such thing as... (Score:3, Informative)
I mean, look at the definition:
1. To decrease the velocity of.
This is meaningless. Decreased with respect to what? I can select a reference frame where the velocity has increased, not decreased! This "definition" is bogus. A forgiveable error, seeing as the dictionary authors are not physicists, but still an error.
The real, physical definition of accele
Re:no such thing as... (Score:2)
velocity Audio pronunciation of "Velocity" ( P ) Pronunciation Key (v-ls-t)
n. pl. velocities
1. Rapidity or speed of motion; swiftness.
2. Physics. A vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.
3.
1. The rate of speed of action or occurrence.
2. The rate at which money changes hands in an economy.
Re:no such thing as... (Score:2)
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]
Re:once again... (Score:2)
What about the idea that the system where such a slip is attributed to the individual but not the production environment with all its facets is intrinsically flawed ?
CC.
Re:once again... (Score:2)
CC.
Re:Why? (Score:2)
Re:Why? (Score:2)