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And that's why we didn't test one ourselves back in the 60s. You need a special kind of attitude to be willing to fly one of these things over your own country.

Or perhaps just ready access to barely-populated Arctic regions where nobody's watching you drop nuclear reactors around.

These things are the most over-the-top method of beating missile defenses. A normal response would be to just deploy more missiles, which are cheaper and faster to build than defense, so it's easy to keep up. But no, apparently they went in this direction.

Putin has a certain reputation to maintain?

The simulation with warheads dropping on Florida reminded me of the old idea of dropping Tungsten rods from orbit onto your enemies, I'm surprised they didn't propose that one too.

>These things are the most over-the-top method of beating missile defenses. A normal response would be to just deploy more missiles

Deploying more missiles would be visible and would clearly demonstrate aggressive intentions.

In a way that saying you are developing nuclear-powered ones does not?
I think if you count public opinion then it may be more acceptable to have small number of advanced cruise missiles than to have more missiles.

For example what sounds more aggressive, 10 cruise missiles or 1000 missiles?

More aggressive than a radiation-belching nuclear ramjet?
We don’t know the design used here. There are nuclear thermal designs that do not enit contaminated exhaust.
Not according to TFA. Do you have a source for your counterassertion? I doubt Tyler Rogoway would get such a point of fact incorrect - even when I've disagreed with his analysis I've never found him to be dishonest.
I have prior training as both aero and nuclear engineer and there are obvious design space solutions? NERVA was an open cycle reactor meaning the propulsive intake air made direct contact with the core, and ablation is what caused radioactive exhaust. Closed cycle designs are more typical in production systems in which a high temperature conventional radiator would transfer heat from the core to the jet reaction chamber. The article is flat out wrong/misinformed.
They've signed agreements limiting the amount of nuclear weapons. This is an intent to improve capabilities while staying in the framework of the treaty.
You need a special kind of attitude to be willing to fly one of these things over your own country

America tested nuclear weapons in its own country https://en.wikipedia.org/wiki/Trinity_%28nuclear_test%29

The primary nuclear powers stopped doing nuclear tests decades ago for very good reasons. We're coming up on 30 years since the US or Russia has detonated a nuclear weapon.

At the time of Trinity, there was a very poor understanding of the consequences.

No; there wasn’t. We clearly didn’t know the exact numbers to expect from the detonations, but we could clearly predict that exploding bomb A is going to cause a fallout of scale 5 to 10. In the case of war you’d want to know if you’re about to kill 500k vs 1m people, but ethically speaking this number is already vastly over something to be considered OK.
https://en.m.wikipedia.org/wiki/Castle_Bravo

Castle Bravo's yield was 15 megatons of TNT, 2.5 times the predicted 6.0 megatons, due to unforeseen additional reactions involving 7Li,[3] which led to the unexpected radioactive contamination of areas to the east of Bikini Atoll.

> You need a special kind of attitude to be willing to fly one of these things over your own country.

Sadly, Russian leaders seem to have that attitude. About 30% of the adult male population was killed in World War II.

> At the most basic conceptual level, the weapon could conceivably reach supersonic speeds, fly at very low altitudes, and have effectively unlimited range thanks to its nuclear powerplant

If the Ruskies have developed a reactionless rocket engine capable of crashing further down range than experimental error, I would keep silent as well /s

Reactionless? Presumably the reaction mass would be... air.
Oh my.. Never thought of that. Surely it does not use the atmosphere as the primary circuit coolant?
That's one of the ways these could run, yes. But hopefully not the way this one is -- there are direct exchange and indirect heating methods that have been researched.

Check out Project Pluto on Wikipedia [1], and the Direct Air Cycle part of the Aircraft Nuclear Propulsion page [2]. From the Pluto page,

"The principle behind the nuclear ramjet was relatively simple: motion of the vehicle pushed air in through the front of the vehicle (ram effect), a nuclear reactor heated the air, and then the hot air expanded at high speed out through a nozzle at the back, providing thrust."

1 - https://en.m.wikipedia.org/wiki/Project_Pluto

2 - https://en.m.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion#...

while we're at it, have a fun tangential short story by Charlie Stross about rockets, missiles, volatile oxidizers, and more, with only a touch of plausible-sounding scifi nonsense:

https://www.tor.com/2012/07/20/a-tall-tail/

The "unlimited" range comes because the thing is powered by a nuclear reactor, which would run out of fuel eventually but not before reaching any point you want on Earth first. So it doesn't have a limited range in the normal sense of "how far away can I hit something?"- the answer is, as far away as you like.
Does anyone else get a sense of de ja vu from the news this week?

- Nuclear weapons development, specifically targeted at the US

- Trade Tariffs

- Improper security classification in the whitehouse

- Israel, Iran threatening war

- China becomes a dictatorship

Feels like we're going backward in time for some reason.

It's the inflection switch from globalism, back to nationalism. A substantial increase in military conflict is guaranteed to come from it. We'll also see a massive leap forward in new, particularly stunning technologies again as nations begin to aggressively compete through technology to ensure survival. Nothing drives a leap forward quite like that.
How long till we reach the point where the only viable strategy against the enemy bot ai is to give full control to our bot ai? Even smallest delay would matter so too dangerous to have human in the loop.
Never, since you have asked this question.
Never because when you surrender your freedom the cure will be worse than the disease, always.
Not sure why you were downvoted. I think that's a terrifying statement but I don't see any strong evidence that you're wrong.
I'm being downvoted because it's simultaneously terrifying to most people and an unpopular opinion. It's pretty blatant that's what is going on however. China for one is leaps and bounds ahead of the US in progressing down that path (they hardly ever deviated from the extreme nationalism path, for a mere decade roughly). Xi will push it a lot further now.

I don't see a good argument that globalism (as we knew it) was going to continue perpetually, that there would be no inflection occurance. It makes perfect sense that a trend like that would have an inflection and go the other direction eventually.

There are chances that after the next substantially increased military conflict, you and I are dead. And so is practically everybody else. I fail to see the "stunning technologies" we could get from that.
I disagree. The major nuclear powers won't instigate nuclear war of that sort unless their territorial integrity is threatened. That will remain the pull-back point no matter the conflict.

The technological leap that I'd expect, will begin to accelerate as the tension between large nations builds over the next decade. It's clear there will be a big competition between the powers in the form of an AI race for example (already underway), and it won't stop there. There's a very large gap between Cold War style conflicts coming back into commonality, or even moving a bit beyond that, and everybody deciding to commit nuclear suicide and kill each other.

>We'll also see a massive leap forward in new, particularly stunning technologies again as nations begin to aggressively compete through technology to ensure survival. Nothing drives a leap forward quite like that.

This attitude assumes the linear progression of conventional warfare that existed among humans until the 20th century. A large scale nuclear exchange will be the end of us all.

I wasn't assuming global nuclear war in that scenario. You can see a large increase in armed conflict around the globe due to nationalism sparking conflicts, without the US and Russia nuking each other, or the US and China nuking each other.

Russia goes into Belarus or Ukraine, maybe Kazakhstan. If you're a dictator like Putin and you can't expand your economy organically, you eventually try to do it through invasion.

China will go after Taiwan sooner than later. In another ten years they'll be close enough to parity with the US to likely do it and have the odds strongly in their favor of safely getting away with it.

The mess in the middle east will continue. There's still a high risk the US ends up at war with Iran, whether drawn in by Israel or otherwise. Saudi Arabia wants to become a nuclear nation. Both Saudi and Iran are practically guaranteed to reach for nuclear weapons in the coming decade or two. Saudi will want to get themselves positioned technologically in case Iran goes for that.

Japan will probably begin/continue gradually re-arming.

The major nuclear powers will go on a nuclear weapon upgrade spree, in competition with each other. That has already begun. China's moves there will be very interesting, given their (supposedly) relatively small arsenal.

We'll very likely see the US, China and Russia deploy weapons to space. That'll add to the tensions.

> the linear progression of conventional warfare that existed among humans until the 20th century

In fact, one major reason for the post-WWII institutions such as the UN, EU (then called something else), and others was to prevent another war. One major reason for preventing war (there are lots of good ones!) cited by leaders was that the technology of destruction had improved to such a point that another war could devastate civilization - that was over 70 years ago.

The joke's on Russia. American anti-missile defences couldn't stop their old missiles anyway!
It's baffling why either Russia or China would be concerned about US efforts around missile defense. There's no scenario in the next 20 years where any nation can stop 50 or 100 incoming nukes. I've always assumed it's mostly a propaganda battle, as Russia can't be that stupid. They can't afford to spend what the US can to develop missile defenses over the coming decades, so they want to reassure their people that it's not a problem regardless.
Have you really thought this through?

Did you realize that China is still in a state of civil war with Taiwan?

The two had a civil war after WW2. The Taiwan side lost the mainland, and fled to Taiwan.

Normally, when you lose a civil war, you don't create a new government. Otherwise, when the United States had their own civil war, then the southern states would have created the Confederate States of America, and slavery would still be alive and legal today.

Do you agree with this premise?

Taiwan is very strategically important to China. But, the United States is now using Taiwan to contain China. And they are using all the excuses like democracy and all that, but it's easy to see through the propaganda. Otherwise, why isn't Saudi Arabia a democracy by now?

If you think through all the angles, then you might actually realize the insane rationality behind China's motives.

That said, the United States is not China's enemy. But with the way geopolitics plays out, the United States is now firmly committed to securing Taiwan. Thus, both nations are now going to head into conflict.

The thing is, any military conflict between the United States and China, will turn nuclear. Once those missiles start flying, then sell your stocks, because the world is going to burn down. This is a pretty grim analysis, so I hope it never happens.

Well it is not just Taiwan, China also has a beef with Japan, which the US is committed to defending too.
The one china policy is retarded. One would hope that the US government would stand with a long-time ally above passing pressure from an authoritarian dictatorship.
If you are going to strike first, you really care about taking out as much counter strike possibilities. If 10% of your target's arsenal get's to retaliate because of missile defense systems, that is terrible for the first-striker.

Even if you don't want to strike first, there is still a great advantage to being able to do it better. Especially if your adversary knows about your capabilities but not your intentions. See for example north-Korea wanting nuclear weapons. Something similar might have played a role for Pakistan. Being a nuclear power gets you seats at certain tables. Being a more dangerous nuclear power gets you a better seat.

This strategy has the weak point of enticing preventative measures, but it is a strategy at least.

US may have nearly 50 ground based interceptors now. How well they work against chinese ICBMs is anyone's guess. But if you have a design and manufacturing process taht works, it wouldn't take long to churn out 500.

Even 50 is a serious threat to China. If the US and China suddenly spiral into major direct war, China is vulnerable to a US first strike. A first strike against their ICBMs (but not cities) that is 50% successful would leave China with a fairly small second strike capability. Leaving China with the choice of trying to nuke the biggest 30 cities in America, knowing the US might shoot down half, or holding them in reserve. And if the try to nuke US cities the US would probably retaliate with 2,000 weapons.

This is wildly unrealistic speculation. If any country nuclearly bombed any other country, it better be prepared to face the rest of the world for it.
I have just such a scenario for you. Laser weapons deployed on a SpaceX BFR. The anti-missile Boeing-747 based laser weapon was cancelled by Robert Gates in 2012 [1] because it had limited range (about 60 miles). Put the same weapon in vacuum though, and the range extends potentially to thousands of miles. A single laser like that could potentially zap dozens of incoming ICBMs. Make these nukes fly in the lower part of the atmosphere though, and the laser won't be able to reach them.

[1] https://en.wikipedia.org/wiki/Boeing_YAL-1

They contend the interceptor missiles can be quickly re-purposed to deliver nuclear warheads.

EDIT: or the missile installations, I don't remember exactly.

I don't have a link for you, but I remember Putin saying this in the Stone interviews.

Correct and level-headed response.
Maybe but either way the era of USA unilaterally pushing wars just ended. Russia with their hypersonic nukes and proxy wars wins have just made western imperialism via war and culture have very high costs.
I don't see how this in any way changes the stalemate of mutual assured annihilated.
MAD under ICBMs allowed us to get our weapons off before we were hit. This tech would allow for very little warning and could potentially take out enemy missile sites before launch.
Nothing has changed at all in fact. For better or worse.

Russia just rattled their sabre because they're desperate. They've recognized an inability to keep up economically with the US and China, and they will fall further and further behind because of that.

Russia's population hasn't expanded in nearly four decades. In that time the US has added 100 million people. China added 400 million people. That population expansion is an economic weapon.

Russia's economy hasn't expanded since 2006-2007. Putin entirely failed to transition the Russian economy off of dependency on energy prices. Without economic growth, they can't keep spending more on their military. Meanwhile the US and China perpetually expand their economies.

The gap between the US and Russia economically has gone from 11 to 1 in 1989, to 15 to 1. And it's worth noting that output gap in 1989 was already extreme, as Russia was effectively a bankrupt nation at that point. That the US has continued to put distance between it and Russia economically, is a massive failure by Putin. Or to put it in another perspective, Canada now has a larger economy than Russia.

And then the China story. Well, that's just a joke of a comparison. In 1989 China had an economy 1/3 smaller than Russia. Today it's 10 times larger. It leaves Russia wilting in contrast, they've become a second tier power.

While your logic makes sense, there is far more to war then economics, otherwise the middle east wouldnt be a mess, and then there is the vietnam war.

Something has changed greatly. It is the fall of globalism and the rise of nationalism. Putins reminder he has the will to use MAD is sign of the new times.

With the current anti-immigrant nature of the American right, the US will start to stagnate in population over the next decade if those people are not removed from power.
I agree with all your points and it makes the US obsession with Russian influence ridiculous IMO.
I'm guessing you're too young to remember the era of MAD, starting in the 1950's going thru 1990 and the fall of the Soviet Union. The emphasis is on "mutual" - both the US and the Soviets had arsenals which were ... excessive. The Chinese did not participate because A) they couldn't without substantial expense, and B) "Go ahead, you guys blow each other up while we watch."
The good news is, no one wants a nuclear war anymore... at least I hope.

I think what changed is largely trade. China, usually the USA's enemy, has benefited enormously by trading with the USA and providing a cheap labor pool for manufacturing after Unions made it too expensive to continue manual manufacturing in the United States.

So if my theory is true, it's probably worth allowing vestment in our fellow nuclear superpowers. Seems backwards, but most things in economics and game theory are.

Unions didn't make it too expensive to manufacture. China just made it way cheaper (slight difference there). A Union made product doesn't increase the cost of the product much, but employing people at wages that provide a moderate income level does reduce profitability.
The unfortunate thing is that Putin has signaled that he's willing to use tactical nukes in a regional conflict, and the U.S. is signaling back that they're willing to do the same. A tac nuke detonated anywhere would be a globally destabilizing event, and a regional nuclear war would be a catastrophe.
> I think what changed is largely trade.

Somewhat famously, this belief was widespread before WWI - who would want to fight a war when we're all profiting so much from trade. The two biggest wars in history were fought in the next 35 years. The current US government likes to disregard every rule of international relations (and fire or fire all the professional diplomats). Those rules exist because, while they are frustrating in the short term, they prevent wars and promote progress in the medium-to-long term. Politics and international relations are not under immediate control of political leaders - many didn't want war in Europe, but they had started the mechanism and couldn't stop it. The idea of those rules is to never get in that position again.

I'm glad that this story notes the elevated isotope detection levels last year and the possibility that the US detection plane sent up around that time may have been doing some classified investigation of evidence of an engine of this sort. The article sadly (I mean, of course, but still sadly) has nothing conclusive or very new to say on that topic, but it's still interesting to see others are also curious about whether there's a link.

Makes me wonder also, though probably a lot less likely of a link, about the other story run by thedrive recently of the released FAA and ATC conversation regarding the unknown, fast moving, large white airplane-like craft that wandered up the west coast late last year.

I'm not sure if an infinite range nuclear-reactor-containing "cruise missile"'s visible characteristics would necessarily be "missile-like", i.e. a cigar with small fins, or if it could reasonably at that point just be... an airplane. It would be ballsy as hell for a Russian experimental nuclear-missile-plane to fly deep deep into American airspace in a common corridor with civilian commercial airliners, like, that would seem to be way too far into an insane possibility that would demand a war-like response, and it's far likelier to have been a US craft from a base in the region, but... it would really be the ultimate test of the system's penetrative and evasive capabilities, if it were such a thing.

What do other folks think?

Running a live test of a nuclear powered aircraft/drone would certainly be an environmental incident (I'm avoiding the use of the word "disaster" until one crashes).

Running such a test in the airspace of a potential 1st tier opponent would be madness - it would absolutely be seen as a warlike act and repercussions would be immediate and widespread.

It's not like having a moving radiation source would be "stealthy" in any way - after 9/11 many US police departments bought portable Geiger counters so tracking one would just be a matter of correlating the readings.

Usually UFO sighting clusters are correlated with USAF testing.

The 80s for example were mostly cruise missile and stealth fighters. In my area of upstate NY, there were a lot of sightings of tomahawk missiles operating out of Plattsburgh and Rome AFB testing the tercom navigation system. In the 90s, there was some sort of hovering drone and hypersonic aircraft.

It’s a reasonable assumption that the military planted or ginned up the aliens narrative to bury the story in plain sight. My first assumption is that this is the same thing.

I'm curious if the orbital infrared detection satellites we have would see this object. Seems like the theory of operation means it has to be ridiculously hot to work.
Anyone knows of some reading material on how such an engine could technically work? I wonder how a nuclear reactor could create propulsion.
IIRC in Feynman' Surely You're Joking, Mr. Feynman, some government folks surveyed the people working on the Manhattan Project for prospective usages of nuclear power to patent and a nuclear powered airplane was one of his first ideas, using the heat from the nuclear plant to heat air for a jet turbine.
To a very simple approximation, heating air expands it. If you control the shape of the space around it, you can expand it more in one direction than the other. That generates thrust. This is the idea behind ramjets.

Meanwhile, nuclear reactors are hot, and this can be used to heat up air.

Usually when you are testing things, they will fail a lot. Like SpaceX, a lot of boosters crashed, that doesn't mean it is less awesome what they developed and it worked in the end once they got kinks out.

This is weird article.

Why would US bother? All the news about new Russian missiles were mostly for interior propaganda consumption anyway.