The ¬NED pin goes low on detection of a nuclear detonation [pdf]

http://www.maxwell.com/products/microelectronics/docs/HSN1000_REV3.PDF

by robinhouston • 15 years ago

146 77 15 years ago

fleitz• 15 years ago

  while(ned_pin) {};
  party_like_its_1999();

pjscott6• 15 years ago

Remember to declare ned_pin volatile. (Sorry to be pedantic, but I was getting physically uncomfortable about the possibility that it might not have been declared volatile.)

sjwright• 15 years ago

You're physically uncomfortable about indefinite 1999-esque partying? Do you have something better to do when !ned_pin?

geuis• 15 years ago

Here's a link to the product page, http://www.maxwell.com/products/microelectronics/product.asp....

Maxwell makes an entire array of microelectronics components. These are generally meant for use in devices that are deployed into space environments.

JonnieCache3• 15 years ago

"FOR SPACE"

Holy shit.

So this is to protect your orbital weapons platform from EMP blasts?

pjscott6• 15 years ago

Or anything you feel like putting in space, that you worry might be near a nuclear explosion or other source of intense ionizing radiation at some point. Be prepared, as the boy scouts say. I assume that maxim goes double in space, considering how expensive it is to put things up there in the first place.

burgerbrain2• 15 years ago

ICMBs go through space you know.

dmm• 15 years ago

How much does this stuff cost?

trobertson• 15 years ago

I don't think they do regular consumer stuff, it looks like everything is special order. According to this page [1], you have to contact one of their business partners in order to arrange any purchases.

[1] http://www.maxwell.com/products/microelectronics/where_to_bu...

stevenrace• 15 years ago

Seems to be available for $150/ea @ http://rcfreelance.com

shabble• 15 years ago

There's some interesting material on the Honeywell HX5000 process (Silicon on Insulator - usually synthetic sapphire) for radiation hardening.

There's an interesting (if somewhat technical) document here: http://www51.honeywell.com/aero/common/documents/myaerospace...

idoh2• 15 years ago

So, my mom is a former Maxwell employee who now does her own defense contracting, and makes this same type of part.

As I understand it, when there is a nuclear event, it generates x-rays followed by the EMP. The goal is to have warheads in flight to be able to continue to their target, so the strategy is to employ an NED. When an event is detected, the warhead shuts down its electronics for the duration of the EMP, and then powers back up.

With her NED, she uses an ASIC for detection. I might get some details wrong, but the ASIC has a physical array in it, and the x-rays flip bits in the array. When enough bits get flipped, one can infer a nuclear event. Because it is an ASIC it is really small, which has important advantages for space-born avionics.

kprobst• 15 years ago

I thought EMP affected electronics regardless of whether they are powered at the time of the burst or not?

ynniv• 15 years ago

You can harden your circuits against EMP, it's just expensive and almost universally unnecessary. Almost.

burgerbrain2• 15 years ago

Perhaps the idea is to disengage delicate circuitry from long potentially antenna like circuits.

Daniel_Newby3• 15 years ago

EMP generally refers to the radio-frequency flash. This device is for the ionizing radiation flash -- gamma rays, x-rays, and neutrons -- that can be extremely damaging to devices that are powered on. For example, the ionizing radiation can cause power transistors to turn on unconditionally, which can fire rockets, burn out power converters, and so forth.

bisrig• 15 years ago

That ASIC idea is pretty neat - it kind of sounds like taking the problem of single event upset and turning it into a solution, pretty clever.

kennywinker• 15 years ago

Do you have mixed feelings about this? Your mom's part in WMD technology, I mean. And how does she feel about it? This is a serious question.

I genuinely wonder if people who work on this kind of stuff feel conflicted about it regularly, or don't think about it, or feel strongly that they are doing good.

nraynaud3• 15 years ago

my sister and mother where in WMD, my father was in Oil industry. My only sane options where either compete with them by going to High Speed Trading in African originated goods markets or give up and become a Hippie, I mostly took the later option and live 400km from them.

idoh2• 15 years ago

Sorry for the late response to this. I have had mixed feelings for a while - it gives a good living to the family, but on the other had we all want to work towards the betterment of the world.

For my mom, at first she was very gung ho about it - arsenal of democracy and the importance of having a strong nation. Now she is having second thoughts, and is looking to follow her passion which is something in the education space.

giardini2• 15 years ago

When an event is detected, the warhead shuts down its electronics for the duration of the EMP, and then powers back up.

I doubt this, since the EMP is moving at the speed of light, whereas the delay times inherent in most circuitry and the time required to power down most circuitry would be at least an order of magnitude (most likely more) larger.

sophacles• 15 years ago

Why does the rate of propagation matter? I presume that during the course of the explosion there are several sequential phases. If phase x emits some non-EMP but detectable signal, say an X-Ray burst and phase y emits the EMP, both of which propagate at the same rate, then you have time(y) - time(x) to respond to detecting x before the EMP from y reaches you.

Explosions, like all other macro scale phenomena are not instantaneous, they just appear so until an appropriately small time step is applied.

nraynaud3• 15 years ago

I've worked for a French military chopper (Tiger, NH-90) company, and they do the same, they short-circuit everything (even the batteries) so that the induced current doesn't grill semiconductors but flows freely through copper. They do that for a very short time, so the cinetic energy in the moving rotor keeps the helicopter airborne.

huhtenberg• 15 years ago

I wonder what a test cycle for this system is like.

marshray• 15 years ago

I like how the logo on the package is the M from *Monsters, Inc."

Something else they make there, I suppose?

JonnieCache3• 15 years ago

They also sell something called the SCS750 which is apparently like a BeagleBoard IN SPAAAACE...

http://www.maxwell.com/products/microelectronics/product.asp...

Datasheet: http://www.maxwell.com/products/microelectronics/docs/SCS750...

Its CPU is in fact triply-redundant, like pjscott was saying. They run in lockstep, and they do some fancy stuff that involves dumping the CPU registers to memory, "scrubbing" the registers and then restoring them. I recommend having a look.

Space is cool. Even when it does have nuclear weapons in it.

kabdib2• 15 years ago

I've wondered about the following:

The firmware controlling a nuke has to have, at some point, a bit or control register it sets that causes the explosion to go off:

    *pKaboom = true;

or something like that. My question is: What is the line of code after that?

    *pKaboom = true;
    /*NOTREACHED*/

I suspect it's more complicated than that (there's an infinite loop of some kind that keeps retrying the command sequence). I also suspect I will never know, short of some very hush-hush software being open-sourced someday. :)

tdicola2• 15 years ago

I doubt the warhead has code to control its activation--more likely it's something like an altitude sensor that controls detonation.

kabdib2• 15 years ago

Think cruise missile. Some code looks at a map, looks at GPS, looks at altitude and velocity, and decides "Yup, this is the spot."

It's probably a lot more prosaic than I imagine.

sp3322• 15 years ago

  ...
  exit(EXIT_SUCCESS); // or maybe failure, if we reach this point? :)

agmiklas• 15 years ago

GCC has a noreturn pragma for this sort of thing. It lets you mark functions as never returning, which can in turn help the optimizer generate code leading up to that function's call sites.

nraynaud3• 15 years ago

I guess there might be some code for mis-firing. Detonating this kind of stuff is tricky.

amatus• 15 years ago

Some missiles run a proprietary operating system for which one has to buy a license per missile. I always found it funny that those instances of the OS were going to destroy themselves.

tdicola2• 15 years ago

Guaranteed to operate in ionizing radiation of 10^12 rad/s. Yikes, that's like 10 billion sieverts/s. Since a dose of something like 10+ sieverts is fatal I'm guessing a human would be turned to a puddle of goo around that much radiation.

Daniel_Newby3• 15 years ago

A nuclear bomb emits a fast flash of radiation over about 50 nanoseconds. Even if the total dose is small, it arrives fast enough to spuriously turn on transistors.

kmm• 15 years ago

1e12 rad/s is 10e9 Gray/s. Sieverts measure something else, dose equivalence.

Interestingly, in this radiation field, every kilogram of mammalian tissue absorbs 10 GW. If this blasts lasts for more than a few nanoseconds, your puddle of goo would be a good guess.

jeffreymcmanus• 15 years ago

the unit test for this thing must be awesome

linuxlizard• 15 years ago

"not authorized for use as critical components in life support devices"

Now try to imagine something using this part in such a way.

/* NED low. Turn off life support. Insurance companies now vapor."

jrockway• 15 years ago

You, sir, have just voided the warranty.

illamint• 15 years ago

Well, this is certainly cooler than anything I work on, nuclear destruction or not.

JoeAltmaier• 15 years ago

"Tested and Guaranteed"

Really? I would like to have seen that.

nobody313• 15 years ago

Money back if not entirely satisfied!

jwallaceparker• 15 years ago

Wow. Great article. This is big.

bravesirrobin• 15 years ago

I just love this bullet point: * Maxwell Technologies Specified, Controlled, Tested and Guaranteed

So, I suppose if you experience a nuclear detonation and the chip doesn't go off, you get your money back?!

dimitar• 15 years ago

I think you can physically model the ionizing radiation of a nuclear event, without actually detonating a weapon, just condoms are tested for elasticity by filling them with pressured air and water.

The detector may have been tested before the discontinuation of underground testing in the US in '92

rphlx• 15 years ago

Hopefully the Built-In Test pin doesn't trigger a nuclear event.

The ¬NED pin goes low on detection of a nuclear detonation [pdf]

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