hello NASA, using the old junk box?

Bullshit. Change of frequency-determining component, requires FCC recert and attendant lab testing time. Depending on application it may also require UL recert. The products we make typically cost $35K for UL cert.

Then we have internal QA time to verify the device still performs nominally over V and T range, ESD immunity tests, EMI immunity tests, shipping and storage (vibration, T shock) tests, etc.

I guess you work in an industry where reliability isn't an issue and there are no consequences if your product fails. That's nice but you need to lose this illusion that your quality "standards" have any relationship to real engineering work.

And you're also trying to tell me that avionics is less tightly regulated than the industry I work in, which is unmitigated balls, bullshit and poppycock.

If you don't want to look like the fool you are, then keep your mouth shut.

I'm sure NASA's stuff has to be - I don't work in aerospace, though. Our shipping and storage tests don't involve twenty Gs of acceleration :)

I was merely pointing out that the OP was spouting utter bullshit.

Not in the market I work in.

They were not rejects at the time.

NASA seriously investigates any possible semiconductor failures in any spaceborne system. My reading of the NY Times sentence says that other parts from the same lot may have had flags raised about them in the past 20 (?30) years.

When and where I was involved (roughly same time period as the Shuttle but completely different branch), no plastic transistors were ever under consideration for anything that got off the ground. Everything had to be metal-can. Look around today for metal-can transistors...

Tim.

Mo pointed out to me that the primary Shuttle mission is now hauling trash away from the Space Station, whose primary mission is to struggle to maintain the Space Station. So the Shuttle is the world's most expensive garbage truck.

John

From NY times today:

Workers also replaced the suspect part of the chain of electronics between controllers and the sensor, known as the point sensor box. The component, like many parts of the shuttle, is based on 1980's technology and still uses components like transistors soldered onto circuit boards. (Today, semiconductor technology places millions of transistors within a single chip.)

Some of the transistors, which are made by Fairchild Semiconductor, came from a lot that was suspected of having manufacturing problems, said Steve Poulos, the manager of NASA's vehicle engineering office.

Really, man with a budget like that you'd expect them to have somebody redesign those units. That would only cost a couple of thousand, and less then the travel expenses of all the people involved discussing it.

I am not sure I take NASA seriously anymore. You must be REALLY of your rocker to use 'reject' parts after all that happened and with that much money available. Where did the money REALLY go!

THIS requires an investigation!

between

component,

Steve

expenses

happened

Wow! Even in the old days, our meetings cost more that :-). Most of our managers were engineers and didn't have to be retaught the basics of AC/DC at each setting.

/BAH

Subtract a hundred and four for e-mail.

I haven't read the entire thread, but, as I recall, everything that goes into the shuttle has to be certified, recertified, and then checked again. I suspect that is particularly true these days. Thus, replacing a part or set of parts becomes a hundred million dollar project, whereas just getting and testing old but still certified parts is far cheaper. If it works, don't fix it.

Do you remember when your toaster lasted 20 years? The KISS principle often pays off. I owned a 1968 cessna. The engine could have easily been designed in the 30s. It used magnetos, and had a carburetor. The engine was certified for 1500 hours, and, although I knew at least 50 other pilots at the time, I only knew of one engine failure, and that was on a plane that with 1700 hours on the engine. On the other hand, my car, which is built with bleeding edge technology, is in the shop on a yearly basis for little electrical stuff, generally related to some computer problem.

So you'll be happy this winter to see your house burned down and family suffocated because the replacement transistor I put in your wireless smoke detector didn't work correctly at low temperatures and the Tx frequency was off by 2MHz?

I can tell you I won't be happy to see my signature on the multimillion dollar recall (and lawsuits) that this little oops would generate.

For some industries, $100,000 and 9 months in testing really doesn't seem like much after all, does it?

I'd like to point you to some of the products in question, but don't want to disclose the name of my employer. There are a lot of legacy products that use discrete tx's, and and re-engineering those would be even more than $100,000.

Agreed!

I was on the team to evaluate ALL systems after the Challenger disaster.

One of the things I discovered was that the redundant power supplies were SO redundant that one supply failing took all the others with it.

I suggested a HexFet fix.

But I was told that HexFet's weren't space-qualified.

I allowed as to how, "Well... it's not MY ride."

We got the fastest space qualification ever, for the hermetic package HexFet... I don't remember the part number now, but I can look thru my records and see if I still have the information.

...Jim Thompson

On a sunny day (Thu, 14 Jul 2005 20:49:40 +1200) it happened "Ken Taylor" wrote in :

Yep I do, I am electronic designer. And that is kids stuff. But maybe NASA fired all E designers long ago, and replaced with 'managers' or idiots like you? Complete morons to save on a 12 cent part. From a billion $$ project. Same guys who spend 51 billion on an aniti missile system that does not work? Fuck off.

Figure $100/hr/person as a starting point. "Some meetings" get to be quite short ones if only $1K is budgeted. ;-)

Managers? AC/DC? Well, I suppose...

between

component,

Steve

expenses

happened

That depends on what you mean by "into". The shuttle has in the past carried newer-technology laptops that have had less-than-critical functions, such as displaying the orbiter's current position on a map of the earth, or keeping track of all the supplies in the storage lockers. Those devices required considerably less testing.

We couldn't do that sort of testing, except in a few very specific circumstances. We sell modular systems and the exact configuration is determined by the consumer. Just thinking about the products I'm responsible for, I can think of 3,221,225,472 possible system configurations and there are certainly many orders of magnitude more than this if you look at our full catalog. So QA tests at the subassembly level in the context of a typical system, plus of course any required specific tests for regulatory approval.

For certain applications, we have only a subset of certified components. Regulatory bodies require some very specific system-level tests on those subsets - stress tests on data throughput and power supply requirements, mostly.

Bureaucracy.

And CYA. I got more accomplished at Sperry (now Honeywell) Satellite Systems Division than most... due to my asshole personality... I've never been reticent to stomp anyone who deserved it ;-)

Plus it helps to not be a direct employee.

...Jim Thompson

On a sunny day (14 Jul 2005 03:04:30 -0700) it happened snipped-for-privacy@larwe.com wrote in :

------------------------^^^^^^^ Not only is that bull, NASA space shuttle and related stuff is no consumer project. For example (consumer) changing a transistor type will likely need no re-certification. In INDUSTRIAL design it will not even need a discussion on a lever higher then the local technician (looking it up in a equivalent list). In an organization that only builds specific EXPERIMENTAL stuff it could be considered part of the design improvements, as as such come under different rules. And as AERONAUTICS replacing a transistors with parts from a unit that is known to be defective is a crime.

Yea, the world has come to an end, for the US and NASA at least.

On a sunny day (Thu, 14 Jul 2005 12:21:02 +0200) it happened Rene Tschaggelar wrote in :

happened

LOL, so we should reduce size and communication lines a bit... MNASA (Micro NASA)?

Look at a company like scale composites. Look at their budget. If indeed (as others suggested here) the paperwork (cost) PREVENTS improvements (to safety for example), then for sure we can prove in front of congress that paperwork needs to go? No, bad idea, won't work. Then the US has come to an end... But we already knew that. The Chinese will be first with a manned mars mission ;-)

RIP (UP) NASA

True. My experience on an (un-manned) space flight project was that testing was done at a circuit board level, box level, sub-system level, and spacecraft level. Once a component was flight certified, any changes would require a full re-test at all levels. Testing involved functional tests, vibration and shake tests, EMI/EMC tests, and thermal vacuum tests. This is a lot of time in testing (months and years). The cost is in the manpower, not the components.

Craig