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Probe Crash Due to Misdesigned Deceleration Sensor
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.
Look on the bright side. The craft was not a complete loss, and it was the first probe to successfully test the Interplanetary Superhighway. (Article with pictures) Now that we know the IPSHwy works, we have the capability to launch cargo ANYWHERE in the solar system.
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 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.
Javascript + Nintendo DSi = DSiCade
... that human error can happen even in the most expensive projects.
This signature was left intentionally blank.
I wish POLITICIANS would stop judging accidents with NASA and spaceflight in general as "wastes".
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.
Reply or e-mail; don't vaguely moderate. Ex-O'Reilly/MIT employee, now a full-time Google employee.
The scientists got their samples and the public got a cool crash video
But it takes a rocket scientist to really screw things up.
They had the silly thing in reverse.
A fine is a tax you pay for doing wrong and a tax is a fine you pay for doing all right.
I read the same story here earlier today, and it also says that it was installed backwards.
(S(SKK)(SKK))(S(SKK)(SKK))
You didn't read the article very well. It says that the specs said the part should go in backwards. From the article:
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.
Javascript + Nintendo DSi = DSiCade
...and make some sort of Genesis joke but there just isn't anything funny at all about the damn group.
When told about its demise, Peter Gabriel responded with "So?"
Second (or third if ya count the dropped sattelite at Goddard about 18 months ago) screwup by Lockheed on a recent NASA project. Knowing NASA, they'll likely give LockMart a bonus for that performance ;)
Haven't we had enough stories about sensorship today?
You'd think the siseneG would have been a tip off!
Genesis crash linked to upside-down design
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 events designed to release the parachutes. When the capsule - which blazed into the atmosphere at 11 kilometres per second - decelerated by three times the force of gravity (3 Gs), the sensors should have made contact with a spring.
"It's like smashing on the brakes in your car - you feel yourself being pushed forward," says NASA spokesperson Don Savage.
The contact should have continued as the capsule peaked at a deceleration of about 30 Gs. Then, when the capsule's deceleration fell back through 3 Gs, the contact would have been broken, starting a timer that signalled the first parachute to release.
"But it never made the initial contact because it was backwards," Savage told New Scientist.
Wrong orientation
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.
They still have to find out why that design error was not caught," says Savage. The mission's Mishap Investigation Board will continue to investigate the problem.
"This single cause has not yet been fully confirmed, nor has it been determined whether it is the only problem within the Genesis system," says the board's chairman Michael Ryschkewitsch. "The board is working to confirm this proximate cause, to determine why this error occurred, why it was not caught by the test programme and an extensive set of in-process and after-the-fact reviews of the Genesis system."
So far, Savage says, the design flaw does not seem to be shared by NASA's Stardust mission, which will use a similar parachute system to deliver samples of a comet to Earth in January 2006.
The $264 million Genesis mission launched in August 2001 to study the composition of the early Solar System, which is thought to be reflected in the solar wind.
Jonah Hex
Horror & SciFi Erotic Nudes
Seriously. Correct me if I'm wrong, but THEY're the ones who:
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?
-- IANAEG - I am not an elder god.
All it takes is one ass-umption to make the great space systems contractor to look like an ass.
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.
The clearance system sounds logical. It is not. It is completely arbitrary. -- John Bolton
This isn't a trick question on your high school physics quiz. Just because the term deceleration is not preferred because it is ambiguous does not mean that it doesn't exist. Maybe it's *acceleration* that doesn't exist!
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.
Damn Australian scientists!
;-)
You can't take the sky from me...
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!
Design error: implementor installs the switch as it was designed, which was backwards.
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 the switch could be installed by the implementor, one of which would result in the catastrophy that was wittnesed. (And the designers are saying it was that implementation.)
Post event analysis will say 'Yes, it was implemented incorrectly. Our recomendation is that the design be improved to prevent future implementations this way.'
The claim is that the design was correct, had things been implemented 'as designed'. The recomendation is that the design be improved so that an incorrect implementation is less likely to happen in the future.
-Rusty
You never know...
Lest I get a bunch of "What are you talking about?" responses:
a y_0410 11.html
9 91110.html
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_
-- IANAEG - I am not an elder god.
Isn't this the same situation that resulted in the creation of Murphy's Law. They were doing acceleration tests on humans but they installed the sensors backwards so the tests were useless.
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.
Sheeeeezzzz...
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-
-- -- The Dragon De Monsyne
They installed the switch backwards.
For some reason, I'm reminded of the origins of Murphy's Law. I recall that too was the result of some sensors being installed backwards...
Tedious Bloggy Stuff - hooray?
But we know things like this already. Failure is fine if you learn from it.
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.
-- IANAEG - I am not an elder god.
I didn't realize that up and down were different in metric than the imperial system.
You'd think they would have figured out that the braking switch was in backwards when they saw Genesis's airbags deploy at liftoff.
3... 2... 1... *PFOOF*
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.
I remember reading about an Apollo moon car issue where a core-sample clamp would not work because it was installed upside down. It ended up wasting about an hour of astronaut time. Parts designers should avoid symmetrical designs where things fit, or semi-fit, if misoriented. Design them with things sticking out so that it would not fit *at all* if put in wrong.
Table-ized A.I.
A while back, one of the main things I admired NASA for was the redundant design concept. You just have a backup path for everything.
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.
Don't try to use the force. Do or do not, there is no try.
read about the whole story: http://en.wikipedia.org/wiki/Murphy's_law
(note that the sensors were wired backwards as opposed to installed backwards)
you probably also suggest that there is...
;-)
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'
the absence of light, 'dark'
and negative acceleration, 'deceleration'
You can look up what we call things here
Murphy's law was a quote (people can argue about who said it first) directly related to accelerometers/strain guages and whether or not they could be connected backwards ...
"Flame away, I wear asbestos underwear"
Said another way, When they installed the part, they installed it with the "Up Arrow" pointing up like the directions said, but the people who designed the part had the "Up Arrow" pointing the wrong direction.
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.
Of course, said sticker would have shown up on the invoice to NASA as "sund.explns" and carried a price of $42,000.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
After that capsule crashed, I saw the following headline:
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.)
Table-ized A.I.
There is only negative acceleration.
We've all made mistakes like this, I think. Somehow, you just get things backwards in your head once, and then fix it as a `definite truth' which you don't bother to look at again.
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?
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 acceleration is a CHANGE in velocity. An increase or a decrease. Change is universal. Change can be measured in any reference frame. In some frames, the change is negative, while in others it is positive. No matter which, it is always called acceleration.
Nobody is disputing the usefulness of the term "decelerate," but the OP was quite correct that there is absolutely no distinction between the two.
you are all wrong, the chip was correctly oriented it was the ship that was installed the wrong way ;)
I think it would have been valuable to have the design put out in public (or at least out to the science community) for review.
I'm geeky enough to check sensors for correct orientation, and motivated enough to do it for free.
-Dan
colonization of mars does not seem possible because the body does not rotate on it's axis.
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.
Javascript + Nintendo DSi = DSiCade
As I mentioned in another post, this project was one of the better-faster-cheaper ilk. I think BFC is not entirely without merit, but it was applied in precisely the wrong manner. Whose fault was that? NASA, not LM, and not even JPL. While it's easy to point the finger at LM (a subcontractor to JPL on this), JPL's job is to make sure the design and test were adequate. And NASA's job was to invest resources and conduct oversight. And Congress...
When the final report comes out, we will presumably learn why the sensor was not fully tested -- where was the decision made and why. Until then, all we have is the proximate cause, not the root cause.
The MCO failure was NOT merely LM's bad propulsion database. JPL's navigators saw the errors building and did not act. And JPL did not adequately staff the navigation operations console. And the reason was the emphasis on "cheaper".
The NOAA satellite really was LM's fault, and they will pay for it.
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.
Overrated / Underrated : Moderation
I remember trying to put plastic containers in a field to use as markers for trees (long story) and after about 2 years had to be replaced as they had decomposed
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 for hundreds/thousands of years. This is a worldwide problem.
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: "...this study suggests that practically everything really is made of plastic these days - even the oceans."