4 ms·

Wiki has more information (ok, more like speculation) on what a Fogbank is: http://en.wikipedia.org/wiki/FOGBANK http://en.wikipedia.org/wiki/FOGBANK "Many arm

by latch 16y ago

Wiki has more information (ok, more like speculation) on what a Fogbank is: http://en.wikipedia.org/wiki/FOGBANK http://en.wikipedia.org/wiki/FOGBANK "Many arms experts believe that FOGBANK is an aerogel material which acts as an interstage material in a nuclear warhead, i.e. a material designed to become a superheated plasma following the detonation of the weapon's fission stage, the plasma then triggering the fusion-stage detonation." Also, just because someone's retired doesn't mean you can't ask for help...

mpk 16y ago
The wikipedia article also mentions, [..] the NNSA eventually decided to invest $23 million to attempt to find an alternative to FOGBANK. and, In 2008, following the expenditure of a further $69 million, the NNSA finally managed to manufacture FOGBANK [..] So not counting the initial cost (which isn't mentioned), we're already up to 92 million USD.
- burgerbrain 16y ago
  All things considered (this being the military, government, and science all rolled into one), I sorry to say that I'm a little impressed by 92 million USD. I would have expected it to run a few orders of magnitude higher.
  - djcapelis 16y ago
    Yes. My guess is we had some information on them and the money was spent to fill in the gaps.
    - wlievens 16y ago
      Indeed. The blog post seems to assume no reverse-engineering occurred. That means they assume that reverse-engineering some highly complex thirty year old technology in a top-secret military context would somehow cost significantly less than that number.
- hartror 16y ago
  The US no longer tests Nukes right? So how do they know the new stuff works I wonder . . .
  - ceejayoz 16y ago
    My understanding is that they simulate them via supercomputing. I imagine this fact has caused a few Pentagon generals to go bald prematurely.
    - jfb 16y ago
      A friend of mine from college works at Livermore labs doing exactly this (simulating, not going bald.) He can't really talk about work, but it certainly seems like a pretty good gig for a physicist.
    - InclinedPlane 16y ago
      As far as I can tell the US hasn't had a nuclear test that went far different from expectations since the 60s. And modern nuclear warheads haven't used dramatically different designs for quite some time. Given that it's a pretty good bet that all US nuclear weapons in service are reliable.
  - GHFigs 16y ago
    4 of the top 20 super computers in the world, and another 2 in the top 100[1], are operated by the US National Nuclear Security Administration. What do they do? "One of the primary missions of NNSA is to maintain and enhance the safety, security and reliability of the U.S. nuclear weapons stockpile. NNSA, through its Office of Defense Programs, ensures that the U.S. nuclear arsenal meets the country’s national security requirements and continues to serve its essential deterrence role." [1]: http://www.top500.org/list/2010/11/100 http://www.top500.org/list/2010/11/100 [2]: http://nnsa.energy.gov/aboutus/ourprograms http://nnsa.energy.gov/aboutus/ourprograms
  - gamble 16y ago
    Inspections, subcritical testing, and computer simulation. The Russian solution is much simpler: when their bombs reach their shelf life, they're recycled into new weapons. Like the Soyuz versus the Space Shuttle, it's a lot easier to just rebuild a complex system then to predict how it will age. Of course, it does have the tiny drawback of generating enormous amounts of highly toxic waste, but in Mother Russia you can simply dump the waste in a lake.
quanticle 16y ago
Also, just because someone's retired doesn't mean you can't ask for help... That's the case for most problems, but it might not have been possible when dealing with top-secret classified materials like "FOGBANK". The people who retired may have given up their security clearances, which means that you have to go through the whole process from scratch to get them re-cleared.
- ceejayoz 16y ago
  Versus redeveloping it for $80-100 million, that still sounds fairly cost-effective.
- kylecordes 16y ago
  (Caveat: I've never worked on anything that required a clearance, so I know nothing at all about how they work. This might be a stupid question.) It seems to me that asking such a person what they remember about some work years ago, would require only that the person hearing the information have the right clearance. As long as no information was provided to the person telling the story, why would that require that retiree to get a new clearance?
  - lallysingh 16y ago
    Probably a blanket clause that says that you can't disclose classified information at all after you've lost clearance. It's pretty plausible that in an attempt to keep security tight, they're not allowed to discuss it at all to anyone --- situations like FOGBANK are probably the exception.
  - tedunangst 16y ago
    This is a substance that apparently costs millions of dollars to make. It's probably complicated enough that someone is unlikely to remember every detail about it without some hints and prompting. I can tell you all about code fixes I made years ago if you describe the code and problem, but asking me "what code did you write 3 years ago?" gets less certain results.
  - krschultz 16y ago
templaedhel 16y ago
That explanation would also seem to match the name, if only slightly, aerogel and fog share some resemblances.
vilhelm_s 16y ago
The Wikipedia page links to this issue of Los Alamos Nuclear Weapons Journal, which has some interesting additional reporting (page 20): http://www.lanl.gov/orgs/padwp/pdfs/nwj2_09.pdf http://www.lanl.gov/orgs/padwp/pdfs/nwj2_09.pdf Apparently they did have documentation for how to manufacture FOGBANK, but when they rebuilt the manufacturing pipeline the end product didn't pass the tests. After some debugging they realized that back in the 70s, one of the raw materials had been purified to a lower standard than today, and one of the contaminants actually turned out to be crucial to the process. Once they knew that, they could start intentionally adding that contaminant and track the concentration of it.
- aquark 16y ago
  At least they had unit tests for the material. Imagine if they only way to test was to run a whole system test.
InclinedPlane 16y ago
Some background: in a thermonuclear weapon a fission warhead "primary" explodes inside a radiation channel which also contains the fusion/fission "secondary". The explosion of the primary provides the energy for imploding the secondary. Quite a lot of unclassified publications describe the mechanism for this implosion as plasma pressure from the vaporized foam that had filled the radiation channel. In truth the overwhelming force causing the implosion is ablation of the secondary's container via absorption of x-rays. I'm not sure why this error continues to be so widely disseminated, I'd half suspect some government plot to spread misinformation.

by latch 16y ago

mpk 16y ago

The wikipedia article also mentions, [..] the NNSA eventually decided to invest $23 million to attempt to find an alternative to FOGBANK. and, In 2008, following the expenditure of a further $69 million, the NNSA finally managed to manufacture FOGBANK [..] So not counting the initial cost (which isn't mentioned), we're already up to 92 million USD.

burgerbrain 16y ago
All things considered (this being the military, government, and science all rolled into one), I sorry to say that I'm a little impressed by 92 million USD. I would have expected it to run a few orders of magnitude higher.
- djcapelis 16y ago
  Yes. My guess is we had some information on them and the money was spent to fill in the gaps.
  - wlievens 16y ago
    Indeed. The blog post seems to assume no reverse-engineering occurred. That means they assume that reverse-engineering some highly complex thirty year old technology in a top-secret military context would somehow cost significantly less than that number.
hartror 16y ago
The US no longer tests Nukes right? So how do they know the new stuff works I wonder . . .
- ceejayoz 16y ago
  My understanding is that they simulate them via supercomputing. I imagine this fact has caused a few Pentagon generals to go bald prematurely.
  - jfb 16y ago
    A friend of mine from college works at Livermore labs doing exactly this (simulating, not going bald.) He can't really talk about work, but it certainly seems like a pretty good gig for a physicist.
  - InclinedPlane 16y ago
    As far as I can tell the US hasn't had a nuclear test that went far different from expectations since the 60s. And modern nuclear warheads haven't used dramatically different designs for quite some time. Given that it's a pretty good bet that all US nuclear weapons in service are reliable.
- GHFigs 16y ago
  4 of the top 20 super computers in the world, and another 2 in the top 100[1], are operated by the US National Nuclear Security Administration. What do they do? "One of the primary missions of NNSA is to maintain and enhance the safety, security and reliability of the U.S. nuclear weapons stockpile. NNSA, through its Office of Defense Programs, ensures that the U.S. nuclear arsenal meets the country’s national security requirements and continues to serve its essential deterrence role." [1]: http://www.top500.org/list/2010/11/100 http://www.top500.org/list/2010/11/100 [2]: http://nnsa.energy.gov/aboutus/ourprograms http://nnsa.energy.gov/aboutus/ourprograms
- gamble 16y ago
  Inspections, subcritical testing, and computer simulation. The Russian solution is much simpler: when their bombs reach their shelf life, they're recycled into new weapons. Like the Soyuz versus the Space Shuttle, it's a lot easier to just rebuild a complex system then to predict how it will age. Of course, it does have the tiny drawback of generating enormous amounts of highly toxic waste, but in Mother Russia you can simply dump the waste in a lake.

quanticle 16y ago

Also, just because someone's retired doesn't mean you can't ask for help... That's the case for most problems, but it might not have been possible when dealing with top-secret classified materials like "FOGBANK". The people who retired may have given up their security clearances, which means that you have to go through the whole process from scratch to get them re-cleared.

ceejayoz 16y ago
Versus redeveloping it for $80-100 million, that still sounds fairly cost-effective.
kylecordes 16y ago
(Caveat: I've never worked on anything that required a clearance, so I know nothing at all about how they work. This might be a stupid question.) It seems to me that asking such a person what they remember about some work years ago, would require only that the person hearing the information have the right clearance. As long as no information was provided to the person telling the story, why would that require that retiree to get a new clearance?
- lallysingh 16y ago
  Probably a blanket clause that says that you can't disclose classified information at all after you've lost clearance. It's pretty plausible that in an attempt to keep security tight, they're not allowed to discuss it at all to anyone --- situations like FOGBANK are probably the exception.
- tedunangst 16y ago
  This is a substance that apparently costs millions of dollars to make. It's probably complicated enough that someone is unlikely to remember every detail about it without some hints and prompting. I can tell you all about code fixes I made years ago if you describe the code and problem, but asking me "what code did you write 3 years ago?" gets less certain results.
- krschultz 16y ago

templaedhel 16y ago

That explanation would also seem to match the name, if only slightly, aerogel and fog share some resemblances.

vilhelm_s 16y ago

The Wikipedia page links to this issue of Los Alamos Nuclear Weapons Journal, which has some interesting additional reporting (page 20): http://www.lanl.gov/orgs/padwp/pdfs/nwj2_09.pdf http://www.lanl.gov/orgs/padwp/pdfs/nwj2_09.pdf Apparently they did have documentation for how to manufacture FOGBANK, but when they rebuilt the manufacturing pipeline the end product didn't pass the tests. After some debugging they realized that back in the 70s, one of the raw materials had been purified to a lower standard than today, and one of the contaminants actually turned out to be crucial to the process. Once they knew that, they could start intentionally adding that contaminant and track the concentration of it.

aquark 16y ago
At least they had unit tests for the material. Imagine if they only way to test was to run a whole system test.

InclinedPlane 16y ago

Some background: in a thermonuclear weapon a fission warhead "primary" explodes inside a radiation channel which also contains the fusion/fission "secondary". The explosion of the primary provides the energy for imploding the secondary. Quite a lot of unclassified publications describe the mechanism for this implosion as plasma pressure from the vaporized foam that had filled the radiation channel. In truth the overwhelming force causing the implosion is ablation of the secondary's container via absorption of x-rays. I'm not sure why this error continues to be so widely disseminated, I'd half suspect some government plot to spread misinformation.