Maker Pro
Maker Pro

hello NASA, using the old junk box?

F

Frithiof Andreas Jensen

Jan 1, 1970
0
Redesigning any of the consumer products I work with to, say, change
one transistor type, is a minimum cost of six to nine months and
$100,000 of direct costs in engineering, QA testing, FCC
recertification, perhaps also UL relisting (that is an instant ~$35,000
cost for our type of product), and more.

And KNOVING THIS people STILL wonder why we are getting whupped by the Asian
competition!!
 
T

Tim Shoppa

Jan 1, 1970
0
You must be REALLY of your rocker to use 'reject' parts after all that

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.
 
J

Jan Panteltje

Jan 1, 1970
0
Bullshit. Change of frequency-determining component, requires FCC
recert and attendant lab testing time.
That would be a case, but then you never heard of xtal oscillators.
And simple RC transistor mvb designs, like the one a beginner like you
uses, should not depend on the transistor specs that much that is changes.
Most components will NOT have an effect on frequency, especially not in
a junction box hehe.
Nuf said.
 
J

Jan Panteltje

Jan 1, 1970
0
Go ahead then, build a couple - although I would wager that getting the
qualified parts *samples* for QA would be "a couple of thousands" and that
is before you even started on the real units.


I am sure that NASA does not worry about that!
Wait till after lauch and landing of all REMAINING shuttles, they need a new
design, likely foreing engineers will have to be brought in again, as in times
of Von Braun.
 
J

John Larkin

Jan 1, 1970
0
From NY times today:

<quote>
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.
</quote>

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!

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
 
G

Guy Macon

Jan 1, 1970
0
martin said:
That is just so depressing

Try working for Mattel, then. Two weeks from the moment the engineer
sits down and starts doing the redesign to the moment when the
factory in China starts shipping the new design instead of the old.

In the case where whatever was wrong with the old design stopped
production, the Chinese can usually do a redesign that gets the
production line running in a day or two and will run that until the
US redesign is ready.

Needless to say, Mattel is not NASA or even Sony. It is a special
case where quality is far, far less important than cost or speed.
Six to nine months is far more typical outside of the toy industry.
 
C

Craig Markwardt

Jan 1, 1970
0
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.

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
 
B

Bob Monsen

Jan 1, 1970
0
Jan said:
From NY times today:

<quote>
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.
</quote>

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!

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.

--
Regards,
Bob Monsen

If a little knowledge is dangerous, where is the man who has
so much as to be out of danger?
Thomas Henry Huxley, 1877
 
That is just so depressing

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?
 
G

Guy Macon

Jan 1, 1970
0
As the latest entry in the "thinks personal attacks are an acceptable
substitute for evidence, logic, and civil discourse" file, I bring you...

Jan Panteltje said:
Yep I do, I am electronic designer.
Um, yeah. Like you have a clue
And that is kids stuff.
idiots like you
Complete morons

**** off.

REFERENCES:

Jan Panteltje's online resume:
http://panteltje.com/panteltje/electronics/index.html

"A simple 75 W RMS audio amplifier for driving 8 Ohm speakers
-leaves anything else in the dust" - designed by Jan Panteltje
http://panteltje.com/panteltje/amplifier/index.html

Another example of a Jan Panteltje hardware design:
http://panteltje.com/panteltje/lorentz/experiment.html

Jan Panteltje's blog:
http://panteltje.com/panteltje/blog/index.html

Jan Panteltje's SupereJan exquisite meditation technique:
http://panteltje.com/panteltje/superjan/index.html

Jan Panteltje's Who Am I page:
http://panteltje.com/panteltje/jan/who-am-i.html

Jan Panteltje index pages:
http://panteltje.com/panteltje/jan/index.html
http://panteltje.com/index1.html
 
That would be a case, but then you never heard of xtal oscillators.
And simple RC transistor mvb designs, like the one a beginner like you

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.
 
J

Jim Thompson

Jan 1, 1970
0
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

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
 
R

Richard Henry

Jan 1, 1970
0
Bob Monsen said:
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.

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.
 
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,

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.
 
M

Morituri-|-Max

Jan 1, 1970
0
Same guys who spend 51 billion on an aniti missile system that does not
work?

Strange, I thought NASA was the organisation that hit a comet travelling
umpteen thousands of miles an hour exactly where they wanted to when they
wanted to, as opposed to the military here who can't even hit a missile
travelling a few thousand miles an hour right here in their backyard half
the time.
 
M

martin griffith

Jan 1, 1970
0
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
Hmm, let me see,have I got this right?

1) NASA or the contractor spent zillions on testing systems, and they
couldn't do a redundant PSU test properly.
I hate to think what the other test were like.

2) "fastest space qualification ever"
So why did everything else take so long?




martin
 
G

Guy Macon

Jan 1, 1970
0
Bob said:
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.

When I worked on the spaceborne "black box" data recorder for the
Shuttle, one goal was to limit the multi-pin connector (certified
for thousands of connect/disconnect cycles) to exactly two connects
and two disconnects. Why? Because we could, and it reduces the
chance of damage slightly. We did this:

("-->>--" is a connector)

A B C
TEST SET-->>-->>-->>--RECORDER

A B C
SHUTTLE-->>-->>-->>--RECORDER

By always connecting/disconnecting B, we could almost
always limit A and C to two connects and two disconnects.

Remember the Shuttle O-Ring? I was part of the team that made
the system that tested them for flaws. Alas, the joint designers
allowed the O-Rings to see conditions that were out of spec; our
temerature limits did not allow direct contact between the O-ring
and the flame from a solid-fuel booster rocket. :(
 
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