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The combination of - a missile test - involving “isotope power sources in a liquid propulsion system” sounds seriously bad. Am I reading too much between th

The combination of - a missile test - involving “isotope power sources in a liquid propulsion system” sounds seriously bad. Am I reading too much between the lines or is this related to the crazy nuclear propulsion ICBM idea they threw out a while ago?

madaxe_again 7y ago
Not ICBM, cruise missile, and it ain’t crazy (well, from a technical standpoint - as a weapon, it’s totally crazy Dead Hand stuff) - see Project Pluto. What’s being reported, given the context of their proclamation about nuclear powered missiles a while back, I think it’s a reasonable supposition in the absence of further information that they had something go very wrong with a static fire of a nuclear ramjet - probably not a nuclear detonation, but I wouldn’t be surprised if they a) had a supercritical moment and b) sprayed the reactor guts over a substantial area. https://en.m.wikipedia.org/wiki/Project_Pluto https://en.m.wikipedia.org/wiki/Project_Pluto
- eitland 7y ago
  > Project Pluto. Sorry, should have mentioned that the Americans came up with this ugly idea. Edit: And in defense of the Americans they canned it: "Despite these and other successful tests, the Pentagon, sponsor of the "Pluto project", had second thoughts. The weapon was considered "too provocative",[2] and it was believed that it would compel the Soviets to construct a similar device, against which there was no known defense."
  - remarkEon 7y ago
    >The nuclear engine could, in principle, operate for months, so a Pluto cruise missile could be left airborne for a prolonged time before being directed to carry out its attack. This is truly nightmare inducing stuff.
  - yborg 7y ago
    This was originally developed in the 1950's, and the successful development of SLBMs rendered it irrelevant, since as a cruise missile it would have been much easier to intercept than a ballistic warhead, as well as much slower to reach a target, and submarine launch also provided first strike immunity. And this is what happens when your nuclear thermal propulsion system goes prompt critical on the ground. https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/File:Destruction_of_KIWI_Nuclear_Reactor_-_GPN-2002-000145.jpg https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/... This was a nominal 1100MW design, the Pluto reactor was about half this output. It's insane that the Russians are testing this thing over their own territory.
    - HillaryBriss 7y ago
      > It's insane that the Russians are testing this thing over their own territory. It would also be insane if the Russians were testing this thing over someone else's territory. It's just insane.
- elliekelly 7y ago
  > I think it’s a reasonable supposition in the absence of further information that they had something go very wrong with a static fire of a nuclear ramjet - probably not a nuclear detonation Can you explain this a bit more for those of us who know almost nothing about missiles/nuclear weapons. If I'm understanding the Project Pluto wikipedia correctly a ramjet isn't able to fire from a standstill and a nuclear ramjet would require both initial forward motion and then a nuclear detonation (not sure if that's the right word, perhaps just "reaction"). So I guess my question is, how would they safely static fire these types of missiles for testing purposes? Assuming Russia's project uses a similar setup to Project Pluto and has conventional rocket boosters to get the missile to ramjet speed is that what they'd be static firing - the boosters? And if they're testing the boosters attached to the nuclear ramjet without allowing the ramjet's reactor to go critical what would have to go wrong with the static fire that would result in radiation?
  - trevyn 7y ago
    Just force air in with a big fan or jet engine to simulate forward motion?
    - madaxe_again 7y ago
      Jet engine with a huge bypass factor for the compression stage, when testing on a static rig, yes.
  - LorenPechtel 7y ago
    If the ramjet didn't go critical it wouldn't be of much use. The key number when you are talking about an operating reactor is called the multiplication factor--when an atom fissions on average how many other atoms will be split by the neutrons released from that fission. When this number is less than one things just peacefully sit there. If an atom fissions the chain soon dies out. If this number is more than one things get hotter and hotter until it comes apart. If this were the whole story there would be no nuclear power, but there's one very useful detail--a small number of those neutrons are not emitted at once. This gives you a margin to control things. When the immediate neutrons are enough to cause more than one fission you have the state known as prompt critical, you have lost control, the reactor will run wild and destroy itself. (An atom bomb is the same idea, except rather than just edging past 1 a bombmaker pushes the ratio as high as possible so it takes a city with it in destroying itself.) I am aware of two cases where reactors had issues with control rods and crossed the prompt critical line, both were immediately destroyed. SL-1 and Chernobyl. The zone between critical and prompt critical gives you a way to control things. You have time to turn the heat up or down as needed. A nuclear ramjet is going to be designed to operate at a very high power density, it's going to be a lot closer to the line than a reactor is normally run. Stick one toe over the line and you get what SpaceX calls a RUD. Alternately, it might have run too hot, something softened or melted and the core shape changed to cross the prompt critical line, same outcome.
chr1 7y ago
That seems to be the consensus on russian twitter. Would be strange if after stealing everything that was possible Putin and his party of crooks and thieves would manage to create actual nuclear propulsion rocket, instead of animated cartoon and failed experiments.
- CydeWeys 7y ago
  A nuclear propulsion rocket isn't actually a very useful thing, as it spews out way too much radiation to be acceptably used in peacetime. And for war, well, several countries already have enough nuclear-tipped warheads spread around the world to end it, so additional delivery mechanisms aren't really needed.
  - gambiting 7y ago
    Wasn't the argument that a rocket with nuclear propulsion can keep accelerating all the way to the target, so by the time it gets there it travels at speeds that make it completely unstoppable? That would make it marginally more useful than ICMBs during war.
    - garmaine 7y ago
      No, aerodynamics prevent that from being possible. But maybe you’re conflating with hypersonic cruise missiles, which are also being worked on but somewhat orthogonal? In any case, the point of the nuclear cruise missile is that it can be essentially a drone stealth nuclear-armed bomber flying just outside of the other country’s airspace 24/7/365. Or a fleet of such drone missiles.
  - chr1 7y ago
    That's the whole point, narcissist with botox cheeks gets a scary cartoon, generals and bureaucrats get mansions and hotels in europe, ordinary people get high dose of radiation. And no one cares how the cartoon relates to common sense and reality.
    - 7y ago
deleted 7y ago
[deleted]
nkoren 7y ago
Sounds more like this Charlie Stross story: https://www.tor.com/2012/07/20/a-tall-tail/ https://www.tor.com/2012/07/20/a-tall-tail/
gambiting 7y ago
Could it just be an RTG to power the rocket's systems in flight, instead of an actual nuclear propulsion system?
- garmaine 7y ago
  RTGs have way too low power to mass ratios to be used in aviation.
- LorenPechtel 7y ago
  No reason for iodine tablets if a RTG got splattered across the landscape. If iodine tablets do any good there was fission involved. The threatening isotope is Iodine-131, half life of 8 days. It's only found associated with fission or with atom smashers. It poses basically no direct harm, the threat is your body taking it up and putting it in the thyroid where it decays and irradiates the thyroid. Hence when it's a threat you take potassium iodide tablets--basically flooding your body with as much iodine as is safe. The fallout iodine gets diluted by all the iodine in the tablets, you absorb a much lower amount of the dangerous stuff.
theptip 7y ago
Wonder if this could be about nuclear powered torpedos, rather than airborne missiles. Not sure how certain they are on the latter part. We know that there are hypersonic torpedos under development, and an intercontinental nuclear powered drone torpedo seems like it could be an effective weapon.
- theptip 7y ago
  Sounds like it's not this actually, and it is a rocket engine; the Guardian has some other quotes on this: https://www.theguardian.com/world/2019/aug/10/russian-nuclear-agency-confirms-role-in-rocket-test-explosion https://www.theguardian.com/world/2019/aug/10/russian-nuclea...
- LorenPechtel 7y ago
  You're thinking of their Status 6 torpedoes. 100kt, intercontinental range.

madaxe_again 7y ago

Not ICBM, cruise missile, and it ain’t crazy (well, from a technical standpoint - as a weapon, it’s totally crazy Dead Hand stuff) - see Project Pluto. What’s being reported, given the context of their proclamation about nuclear powered missiles a while back, I think it’s a reasonable supposition in the absence of further information that they had something go very wrong with a static fire of a nuclear ramjet - probably not a nuclear detonation, but I wouldn’t be surprised if they a) had a supercritical moment and b) sprayed the reactor guts over a substantial area. https://en.m.wikipedia.org/wiki/Project_Pluto https://en.m.wikipedia.org/wiki/Project_Pluto

eitland 7y ago
> Project Pluto. Sorry, should have mentioned that the Americans came up with this ugly idea. Edit: And in defense of the Americans they canned it: "Despite these and other successful tests, the Pentagon, sponsor of the "Pluto project", had second thoughts. The weapon was considered "too provocative",[2] and it was believed that it would compel the Soviets to construct a similar device, against which there was no known defense."
- remarkEon 7y ago
  >The nuclear engine could, in principle, operate for months, so a Pluto cruise missile could be left airborne for a prolonged time before being directed to carry out its attack. This is truly nightmare inducing stuff.
- yborg 7y ago
  This was originally developed in the 1950's, and the successful development of SLBMs rendered it irrelevant, since as a cruise missile it would have been much easier to intercept than a ballistic warhead, as well as much slower to reach a target, and submarine launch also provided first strike immunity. And this is what happens when your nuclear thermal propulsion system goes prompt critical on the ground. https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/File:Destruction_of_KIWI_Nuclear_Reactor_-_GPN-2002-000145.jpg https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/... This was a nominal 1100MW design, the Pluto reactor was about half this output. It's insane that the Russians are testing this thing over their own territory.
  - HillaryBriss 7y ago
    > It's insane that the Russians are testing this thing over their own territory. It would also be insane if the Russians were testing this thing over someone else's territory. It's just insane.
elliekelly 7y ago
> I think it’s a reasonable supposition in the absence of further information that they had something go very wrong with a static fire of a nuclear ramjet - probably not a nuclear detonation Can you explain this a bit more for those of us who know almost nothing about missiles/nuclear weapons. If I'm understanding the Project Pluto wikipedia correctly a ramjet isn't able to fire from a standstill and a nuclear ramjet would require both initial forward motion and then a nuclear detonation (not sure if that's the right word, perhaps just "reaction"). So I guess my question is, how would they safely static fire these types of missiles for testing purposes? Assuming Russia's project uses a similar setup to Project Pluto and has conventional rocket boosters to get the missile to ramjet speed is that what they'd be static firing - the boosters? And if they're testing the boosters attached to the nuclear ramjet without allowing the ramjet's reactor to go critical what would have to go wrong with the static fire that would result in radiation?
- trevyn 7y ago
  Just force air in with a big fan or jet engine to simulate forward motion?
  - madaxe_again 7y ago
    Jet engine with a huge bypass factor for the compression stage, when testing on a static rig, yes.
- LorenPechtel 7y ago
  If the ramjet didn't go critical it wouldn't be of much use. The key number when you are talking about an operating reactor is called the multiplication factor--when an atom fissions on average how many other atoms will be split by the neutrons released from that fission. When this number is less than one things just peacefully sit there. If an atom fissions the chain soon dies out. If this number is more than one things get hotter and hotter until it comes apart. If this were the whole story there would be no nuclear power, but there's one very useful detail--a small number of those neutrons are not emitted at once. This gives you a margin to control things. When the immediate neutrons are enough to cause more than one fission you have the state known as prompt critical, you have lost control, the reactor will run wild and destroy itself. (An atom bomb is the same idea, except rather than just edging past 1 a bombmaker pushes the ratio as high as possible so it takes a city with it in destroying itself.) I am aware of two cases where reactors had issues with control rods and crossed the prompt critical line, both were immediately destroyed. SL-1 and Chernobyl. The zone between critical and prompt critical gives you a way to control things. You have time to turn the heat up or down as needed. A nuclear ramjet is going to be designed to operate at a very high power density, it's going to be a lot closer to the line than a reactor is normally run. Stick one toe over the line and you get what SpaceX calls a RUD. Alternately, it might have run too hot, something softened or melted and the core shape changed to cross the prompt critical line, same outcome.

chr1 7y ago

That seems to be the consensus on russian twitter. Would be strange if after stealing everything that was possible Putin and his party of crooks and thieves would manage to create actual nuclear propulsion rocket, instead of animated cartoon and failed experiments.

CydeWeys 7y ago
A nuclear propulsion rocket isn't actually a very useful thing, as it spews out way too much radiation to be acceptably used in peacetime. And for war, well, several countries already have enough nuclear-tipped warheads spread around the world to end it, so additional delivery mechanisms aren't really needed.
- gambiting 7y ago
  Wasn't the argument that a rocket with nuclear propulsion can keep accelerating all the way to the target, so by the time it gets there it travels at speeds that make it completely unstoppable? That would make it marginally more useful than ICMBs during war.
  - garmaine 7y ago
    No, aerodynamics prevent that from being possible. But maybe you’re conflating with hypersonic cruise missiles, which are also being worked on but somewhat orthogonal? In any case, the point of the nuclear cruise missile is that it can be essentially a drone stealth nuclear-armed bomber flying just outside of the other country’s airspace 24/7/365. Or a fleet of such drone missiles.
- chr1 7y ago
  That's the whole point, narcissist with botox cheeks gets a scary cartoon, generals and bureaucrats get mansions and hotels in europe, ordinary people get high dose of radiation. And no one cares how the cartoon relates to common sense and reality.
  - 7y ago

deleted 7y ago

[deleted]

nkoren 7y ago

Sounds more like this Charlie Stross story: https://www.tor.com/2012/07/20/a-tall-tail/ https://www.tor.com/2012/07/20/a-tall-tail/

gambiting 7y ago

Could it just be an RTG to power the rocket's systems in flight, instead of an actual nuclear propulsion system?

garmaine 7y ago
RTGs have way too low power to mass ratios to be used in aviation.
LorenPechtel 7y ago
No reason for iodine tablets if a RTG got splattered across the landscape. If iodine tablets do any good there was fission involved. The threatening isotope is Iodine-131, half life of 8 days. It's only found associated with fission or with atom smashers. It poses basically no direct harm, the threat is your body taking it up and putting it in the thyroid where it decays and irradiates the thyroid. Hence when it's a threat you take potassium iodide tablets--basically flooding your body with as much iodine as is safe. The fallout iodine gets diluted by all the iodine in the tablets, you absorb a much lower amount of the dangerous stuff.

theptip 7y ago

Wonder if this could be about nuclear powered torpedos, rather than airborne missiles. Not sure how certain they are on the latter part. We know that there are hypersonic torpedos under development, and an intercontinental nuclear powered drone torpedo seems like it could be an effective weapon.

theptip 7y ago
Sounds like it's not this actually, and it is a rocket engine; the Guardian has some other quotes on this: https://www.theguardian.com/world/2019/aug/10/russian-nuclear-agency-confirms-role-in-rocket-test-explosion https://www.theguardian.com/world/2019/aug/10/russian-nuclea...
LorenPechtel 7y ago
You're thinking of their Status 6 torpedoes. 100kt, intercontinental range.