hello NASA, using the old junk box?

Yeah, but if your car engine fails, you don't come tumbling out of the sky to a fiery death. :-)

Cheers! Rich

When I ran a production line "manned" by women... Mondays and Fridays were bad, as well as menstruation days ;-)

...Jim Thompson

The problem with the single IC is *proving* that it is more reliable. Most single ICs are indeed more reliable that a PWB, but some have hidden flaws. With a 1970s PCB, you can characterize every transistor. With an IC, how do you *know* that one on the transistors buried deep inside the chip isn't marginal?

In addition, there is the possibility of an engineer or an assembler/ technician making an error whenever you make any change. At these reliability levels, that's a major cause of failure no matter how careful you are.

Here is how to calculate whether to replace a 1970s PWB with a single 2005 IC:

Calculate the odds of the shuttle failing as it is now.

Calculate the odds of the shuttle failing assuming that the PWB has perfect reliability.

That sets an upper bound on how much more reliable the shuttle will be with a replacement for the PWB.

Calculate the resources needed to replace the PWB.

Look at your list of places where you could spend those resources to improve shuttle reliability.

If and only if replacing that PWB with something perfectly reliable is the use of resources that will result in the maximum possible increase in Shuttle reliability, beating out all other possible places where those resources could be spent, start analyzing what the *actual* increase in reliability from replacing the PWB will be. If replacing that PWB with something perfectly reliable won't result in the maximum possible increase in reliability for your buck, don't bother trying to figure how much better the IC is; even if it is perfect, the change won't make sense.

Could any of the people that work(ed) on high-rel, aero, or space comment on the above?

Best Regards

Everything to please, eh bum boy?

Having now thought about it some more, maybe the OP does have a point, in a sense. Many of the costs are not intrinsic to space flight, they are man-made. The requirement to certify to high standards severely limits the opportunity to substitute smaller, lighter components that would allow an on-going increase in payload and considerably reduced acquisition costs. The supposed benefit is decreased risk, but one has to wonder whether a 1970s pcb is really that much reliable than a single 2005 IC.

Its hard to believe that we couldn't lower the overall safety slightly and save a lot of money. Its not like there is any shortage of people who want to become astronauts or anything.

Peter Webb

snip more

So when the audiophi(oo)le gurus ask for a special low noise transistor for a moving coil gramaphone vinyl preamplifier They might as well spec ( 2sb737 by Rohm comes to mind)

" I want the transistors form the upper left hand side of the wafer, not done on mondays or fridays"

or is it a bit more sophisticated than that?

martin

Obviously, none. He isn't dead. Yet.

Why does NASA need a new shuttle design? The shuttle has no function, and never has.

John

times

Funny, Here in the States, Mercedes hasn't the poorest service record in its price class.

...Jim Thompson

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Sheeesh! Make that....

Funny, Here in the States, Mercedes HAS the poorest service record in its price class.

...Jim Thompson

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Saabs are great cars, between fires.

John

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Older VW's and Porsches were good at that, too ;-)

...Jim Thompson

Wow! $600K per person-year?! I didn't thing DECland was quite that rich!

I hire carpenters for about $25/hr. A plumber is, perhaps, $75/hr. Fortunately, I haven't needed one of the latter for fifteen years. Things certainly are expensive down there.

I found the benefit of the reviews wasn't so much the review, but in the preperation for the review. It at least forces one to clean up the documentation. ;-)

Doesn't everyone? I'm fortunate. With few exceptions, I've had really good ones that are smart enough to leave the bees alone.

Perhaps, they will use foreign engineers but this time they certainly won't be coming from Europe.

Cessnas don't exactly fall out of the sky, in flames, if the engine quits either.

So, maybe it's an opportunity for the "Human" race?

What portion of a "Ford" NASCAR racer was built by Ford?

times

Whoopie! Ford is leading in NASCAR, at least I think they are (who cares).

Yep. British cars are just *so* wonderful. That's why Ford bought Jag and it was an improvement. They couldn't go down any further.

Fame. Fortune. Applehood and Mother pie. Dunno, but there are a *lot* of people dieing to come here. You figure it out.

You really ought to get back on your meds. The helicopters aren't black at all.