Agni-V ICBM: New capabilities, technologies, strategies

[Karan M]

Thanks Ramana for the insights, plus useful template. I think pretty much all our successful programs match that template. I do think though our big problem is most reviews go noplace, it'll be interesting to see if the KRC reccos after Kargil were actually implemented. Similarly, is what happened in 1998 now documented and lessons learnt or is it again back to tribal knowledge ..!

[ramana]

KaranM, I have no insider insight except a mind that extrapolates form known dots.

One remaarkable thing in WOF is that VSA and AK go to Delhi for funding the IGMP in 1983. They propose among other things a REX or re-entry experiment and present all this to Raksha Mantri. He listens and calls them back. He requires them to revamp the REX with 1 tonne payload.
They re-vamp the program plan and get approval. Since then the Agni payload has never gone down from that figure. Look at the graphic in TSS article. So that means there is a mota lota of that weight in which they have confidence.
The only other data point we have is in the aftermath of POKII in a seminar at IPCS, they said the unit tested was ~500kg. No vehicle in the Agni class has such a low number.

Only Shourya has ~700kg. Some thing to think about.

[SaiK]

Any rough idea of how much weight reduction will happen if the s1 becomes composite? I am thinking at least 5 tonnes.

[Kanson]

I've never seen a comparable level of skepticism about the stated capabilities of any potential adversary. For example, the Chinese have an unquestionably credible blue-water SSBN deterrence platform despite one drydock queen, one at the bottom of the Bohai Sea, and a handful of new ones parked in Huludao and Sanya with their hatches open and zero deterrence patrols in 30 years.

Sir, I seriously don't know whether you are joking/playing around or being sarcastic.

Oh! with weight, diameter and a picture, you can crack up RV's stability parameters?

I will give an aircraft picture, dimensions and weight, can you tell me exactly where its CG and its stability margin?

As a counterquestion, without being associated with the A-V test in any manner, and absolutely no data whatsoever, you can question the fidelity of the test ? And it is upto others to prove that the test was indeed successful ? What's the piskological description of this line of questioning again ? 'You farted' ? Why don't you start by providing reasoning to back up the thesis you postulate ?

From where you find out I question the fidelity of the test? What thesis i'm postulating here? And who is here indulging in 'piskological' posturing? I don't even have a remote idea of what you are taking. If suppose if is this was raised by a friend of mine, I must have asked him, have you woke up from the bed with bad nightmare? But then I even don't know, whether you are making this observation as another discussing member or monitoring forum moderator. What stand I can take and what reply i can give?

[Kanson]

http://en.wikipedia.org/wiki/Automated_Transfer_Vehicle

ATV Jules Verne as it re-enters Earth's atmosphere in a controlled burn-up after undocking from ISS.

For RV, to those who is viewing from the position of point of impact it looks like a fireball trying to fall over them. AT ~3000 deg Celsius, it doesn't look anything other than fireball.

If this video is true, at 00:59 these RV's dont look anything like a fireball to the camera that seems rather close to the point of impact - more like a streak to me, saar.


I mean, a person who got knifed wont say "A point came towards my belly".

But my "comprehension compass" might be off today, (see? a twin MIRV warheads in one mijjile right there )

Thank you hnair for the youtube clip. Without going into the merit of your digression...

from 00:45 to 00:52, You can see for yourself how it looks. Anyway beauty is in the eye of the beholder, isn't it?

[Suraj]

Sir, I seriously don't know whether you are joking/playing around or being sarcastic.

Of course it is sarcasm. Since you seem uncertain, it merely reflects the fact that no one bothers scrutinizing others claims of potency much, while relentlessly questioning ours.

From where you find out I question the fidelity of the test? What thesis i'm postulating here? And who is here indulging in 'piskological' posturing?

To requote your original post:

How we know that fireball looking RV is still intact and holding its internal package from such scorching heat. How we know RV doesn't tumbled, ie. nose up ? How to know, it is not a happenstance but RV followed exactly all the commands from guidance package executing all its mission in glitch free fashion. All these things you can't know by witnessing the splash down.

If it did all these then only you can say as grand success. And for that you have to believe whatever DRDO guys say just as we have to believe BARC/DAE guys.

You're claiming that despite statements by those who have the data to say so, the details of A-V's re-entry aren't certain. Why don't you start by demonstrating why your argument has any weight, before questioning whether or not those who worked on the A-V program can be believed ? They designed it, built it, fired it, tracked it and reported the whole thing in extraordinary detail, arguably beyond that of any P-5 member's initial efforts.

Why don't you give us reason to believe why your question is meaningful ? Independent tracking and monitoring data of any kind at all ? It is not like DRDO claimed the sky is green, for belief to be an article of faith here.

[Kanson]

You're claiming that despite statements by those who have the data to say so, the details of A-V's re-entry aren't certain. Why don't you start by demonstrating why your argument has any weight, before questioning whether or not those who worked on the A-V program can be believed ? They designed it, built it, fired it, tracked it and reported the whole thing in extraordinary detail, arguably beyond that of any P-5 member's initial efforts.

Why don't you give us reason to believe why your question is meaningful ? Independent tracking and monitoring data of any kind at all ? It is not like DRDO claimed the sky is green, for belief to be an article of faith here.

I'm treating your post as from anyother discussing member. If you feel otherwise you can say so.

First of all, pls cut your useless pontificating diatribes and read the original post. If you are not you are committing the same mistake as ramana and you are clutching at the straw, tilting at the windmill.

This is the original post, http://forums.bharat-rakshak.com/viewto ... 9#p1277419

My reply is to merlin. merlin mentioned, by observing the splash down anyone can call it as 'grand success'. I disagreed and mentioned there are other parameters DRDO must watch before declaring it as 'grand success'. I listed some of them what drdo might be looking for and added 'And for that you have to believe whatever DRDO guys say'. Is my reply looks like I'm question DRDO statement? Do you need anymore further explanation ?

Original merlin post to which i replied: http://forums.bharat-rakshak.com/viewto ... 4#p1277354

You're claiming that despite statements by those who have the data to say so

May I ask, How you know, even by chance, others who talk about, don't have access to data, hard data?

[Suraj]

Kanson, merlin is merely regurgitating what DRDO said and not saying anything original himself - that IN ships monitored the splashdown and that they had data exactly where the re-entry would be (or else they would not have had the ships close enough to see it). And DRDO itself called the mission a 'grand success' (or words to the effect). I see nothing in merlin's post that is an original claim or assertion, unless you want to debate the exact adjective preceding the word 'success' that they used. In effect you are responding to the DRDO's statements, not merlin's.

Now, what proof do you have that DRDO are not speaking on the basis of data ?

[Kanson]

Kanson, merlin is merely regurgitating what DRDO said and not saying anything original himself - that IN ships monitored the splashdown and that they had data exactly where the re-entry would be (or else they would not have had the ships close enough to see it). And DRDO itself called the mission a 'grand success' (or words to the effect). I see nothing in merlin's post that is an original claim or assertion, unless you want to debate the exact adjective preceding the word 'success' that they used. In effect you are responding to the DRDO's statements, not merlin's.

Correct point is *ONLY* DRDO can call that as 'grand success' not anyone else. Thats the point i trying to make to merlin or anyone.
IN or anyone observing the splashdown can't have the data to comment or call it as 'grand success'. Grand success is the term introduced by merlin in this discussion so if anyone wants to know the connotation of term 'grand success' in this context, the correct person to contact is merlin.

Now, what proof do you have that DRDO are not speaking on the basis of data ?

And You haven't shown any proof that i'm speaking against DRDO or their statement.

[Suraj]

Correct point is *ONLY* DRDO can call that as 'grand success' not anyone else.

They've already done that.

Avinash Chander, Chief Controller (Missiles and Strategic Systems), DRDO, and Programme Director, Agni-V, called it a “fantastic mission, which has achieved a range of more than 5,000 km.” The success gave India the confidence to go ahead with a larger number of missiles and longer ranges, he added.

V.G. Sekaran, Director, Advanced Systems Laboratory, Hyderabad, described the success as “overwhelming.”

I see your point here - they didn't say 'grand success', but we can use 'fantastic mission' or 'overwhelming' to describe it

[Kanson]

Suraj sir, Thanks for the understanding. Point of my discussion is NOT whether it is a grand success or fantastic mission, but WHO has the authority & data to call that as fantastic mission or grand success.

IN or ONGC or anyone who lends their vehicle for observation don't have the expertise or understanding of the mission, the missile that was tested or their characteristics to comment or pass any judgement on the success or failure of that test.

[Kanson]

And to return to the original post that started this discussion,

One Noob question. What we have all seen is A-5 takeoff only. No one saw the travel path or the splash down. But when Dr.Avinash Chandar says it is a grand success, we joyfully agree. Also in Pok-2 we all the the ground tremble only. No body saw anything else. But why question AK if he claims the POk-2 a grand success.

Err, maybe because even the IN is a witness to the splash down? And SFC folks and other folks witnesses the launch. So if the launch was successful and the splash down and explosion were witnessed it may just, just, qualify as a grand success.

OTOH, only AK and BARC claim that S-1 was a grand success. Does DRDO support that? And SFC concur?

Just as DRDO ONLY has the authority to comment on the success or failure of missiles, ONLY BARC has the authority and possess complete set of data, required expertise in working on that field and intimate knowledge of the device and the test as they are the one who planned the test, know the composition and as well as goal of those test, to call their test as success or failure.

Just as we have to believe DRDO on the success of these tests, we have to believe BARC on the success of POK 2 tests.

AK already mentioned at the end of the interview to Karan Thapar that the arsenal that was being questioned is already with the Command or words to that effect(interested ones can check the clip). That put to rest all noises like, are we going to field TN? are we going to mount TN in our missiles? is the warhead mounted is TN or just fission, etc

[SaiK]

Believes are not measured by definitions of success or failure. Believes are measured by facts and assertions. If the impact on the target video is what you are looking for, I am sure somebody will pop it in on the tube soon. Again, we the people should think that is what we need to believe.

Furthermore, even if a failure happens with delivery vehicle, there exists next chance to prove it right.. the same is not true when one declares nuclear moratorium on tests. When the authority in question declares it is not necessary, and that comes only after years of analysis and discussions.. whereas, when DRDO says success, it is all live and within seconds is reported., that is failure or success. There is nothing lost in declaring a failure for DRDO.. but the whole nation is lost on failure on nuke tests.

It may be the only test needed, but measures and metrics are the ones that enables us to define. Unfortunately, nuke tests are not difficult to detect, and the whole world would only measure what we do, and not what we say. It is easy to roll back , and succumb to np mullahs.. and not necessary to invest heavily on nuclear deterrent. Our environment is such, that we are poised to go nuclear, and there is no stepping back.

We have to answer for everyone, and not for few. The core of DRDO relies on the internal designs that carries the deterrence.. It is like the heart. We can't say, it missed the heart beat or I don't care if an attack comes. We have to ensure it is safe and beating correct.

[Austin]

Can you give me the quote for such assertion? As far as i could remember, he said, he thinks, it is based on 1st or 2nd Russian reactor technology. I don't remember he mentioning that as Soviet reactor.

Via Arun Prakash/Force link

It is, therefore, vital that even as the ATVP pursues its pre-ordained building programme for Arihant follow-ons, the government initiates a parallel indigenous nuclear submarine project in mission-mode. The first hurdle will be the design and manufacture of a pressurised water reactor (PWR), along with the low/medium enriched uranium rods required to fuel it. In 2005, the Bhaba Atomic Research Centre (BARC) had estimated that the ‘ab-initio’ development of a nuclear propulsion plant could take anything up to 12-15 years. The Arihant’s nuclear reactor, awaiting criticality, is of early Soviet era design, and delivers only 90 MW of power, which will limit the boat’s speed as well as endurance. The Chakra has a reactor of more advanced design which delivers 190 MW and invests the boat with higher performance. The indigenous BARC design should aim for around 200 MW output.

[D Roy]

Just for the record,

Admiral Arun Prakash is also the person who has written a few times that the efficacy of the Indian deterrent is beyond doubt and is essentially centred around FBFs in the 300 kt range.

[gakakkad]

one more thing , especially for the ones ,opposing the the kundakulam plant is that , some of the technologies from knpp will be an inspiration for lwrs of future generation of Indian n-subs...One of the reason why knpp had such intense orchestrated protest was because of this reason ..

[Aditya_V]

Austin-> in your link all Admiral Praksh is saying is that Arihant's reactor is a "Soviet Era design", i.e outdated design, not imported from SOviet Union as earlier contended.

[gakakkad]

Austin-> in your link all Admiral Praksh is saying is that Arihant's reactor is a "Soviet Era design", i.e outdated design, not imported from SOviet Union as earlier contended.

arihant reactor was not imported ..



but the design is of 1980s class...also note that arihant is not as massive as the ohio class...(6000 ton arihant v/s 16000 ton ohio)..

[Austin]

Austin-> in your link all Admiral Praksh is saying is that Arihant's reactor is a "Soviet Era design", i.e outdated design, not imported from SOviet Union as earlier contended.

Well they either bought out the design of the reactor or they imported few and both the design , BK in his book mentions of buying 2 reactor.

The point i was trying to make is BARC can be selective with truth and can just show what it wants to ...... the story of reactor design being Russian origin is quite a known one in strategic circle , Admiral Prakash openly confirming the same just gives credibility. Of course you will hear BARC saying all the time its indiginous design.

[gakakkad]

So now bharat karnad has more credibility than BARC/dae..

how does bk know anything about the reactor ? he was not in the team , was he ?

you have a scientist at kalpakkam , saying that the reactor was designed in India and contributions from various parts of India came in ..and that genetleman is being selectiv with the truth , while this 2 bit strategic guru who had even been dismissive of A-5 initially , says the reactor was imported and everyone agrees with him..

[ramana]

I think the thread is going far away from the title.
Please stick to A5 only.

[amit]

Austin-> in your link all Admiral Praksh is saying is that Arihant's reactor is a "Soviet Era design", i.e outdated design, not imported from SOviet Union as earlier contended.

Well they either bought out the design of the reactor or they imported few and both the design , BK in his book mentions of buying 2 reactor.

The point i was trying to make is BARC can be selective with truth and can just show what it wants to ...... the story of reactor design being Russian origin is quite a known one in strategic circle , Admiral Prakash openly confirming the same just gives credibility. Of course you will hear BARC saying all the time its indiginous design.

Sorry Austin that doesn't cut it at all. "Soviet-era" design does not mean the reactor is of Russian origin. Even BK saying India imported two reactors (incidentally I take this factoid with a 1 Kg of salt) does not mean that the reactor on Arihant is of Russian origin. For all you know, the Russian may have helped out with design consultation and design validation and those two reactors that BK claims were imported could have been to help Indian scientists to study their internals. You have presented no proof that BARC lied and that the Arihant reactor is Russian, your original point.

The fact remains that BARC and DRDO are both government organisation. You can't say BARC "can be selective with truth" and then turn around and say DRDO is always pristine in what they say and do. If you question one, then you should also question the other as well.

JMT

[amit]

Oops sorry didn't see Ramana's message. OK will stick to topic.

[Austin]

you have a scientist at kalpakkam , saying that the reactor was designed in India and contributions from various parts of India came in .

My last word on it since this is not the thread to discuss , you dont have to believe BK , you can trust ex Admiral Arun Prakash on it and he is ex CNS and knows his stuff. BK by the way was on NSAB and he was in the know at that time.

On A-5 any reason why they opted for a pure Ballistic Trajectory , is that a limitation of current RV design on A-3/A5 ? Seems to me the RV carries Avionics/Guidance and Warhead but no fuel/propulsion system. One of the gent on the program mentioned that future development will be on MaRV and MIRV.

[Austin]

BTW why do they mention rentry speed of 6 km/sec and Mach 24 , at 6 km/sec it translates to Mach 18 and Mach 24 translated to more than 8 km/sec

[vina]

BTW why do they mention rentry speed of 6 km/sec and Mach 24 , at 6 km/sec it translates to Mach 18 and Mach 24 translated to more than 8 km/sec

Mach number varies with temperature and pressure and hence altitude and different layers of atmosphere and hence not a constant except in specific layers such as tropopause. You need to consider all those factors.

I plugged it into this Mach No calculator from NASA and at 6.5km/s and the max altitude upto which mach no is defined (just put some high no like 150km, the atmosphere is defined only upto 76km or so) , the Mach no for that speed is Mach 24. So yeah, the Mach 24 seems fine.

[merlin]

I did not understand a bit of Kanson's logic so I'm not going to respond to the posts until he/she/it is more clear.

The point I'm making is simple - there is independent verification of DRDO's claims about the success of the A5 - IN ships have recorded the splashdown and in time by analysing the video they will be able to prove that the warhead did explode demonstrating that the RV heat shield did protect the warhead. And repeated tests, if successful, will buttress the DRDO claims.

My opinion is that BARC does not have any independent verification of their claims with respect to Pok-2.

[merlin]

Just for the record,

Admiral Arun Prakash is also the person who has written a few times that the efficacy of the Indian deterrent is beyond doubt and is essentially centred around FBFs in the 300 kt range.

And when I read about that statement I inferred that the SFC does not accept that the thermonuclear warhead created out of the S-1 design is a credible part of the Indian deterrent.

[Austin]

^^ Merlin I think no credible military power worth its salt would accept a complex weapon design as TN no matter how good it may be if its proof tested just ones and when there is a sizzle or fizzle dilemma to it the doubts just add up , considering the armed forces are so isolated in India from actual weapons design , development and inputs ... that they would have to keep faith in AK words and as he says about TN weapons "make that plural" like the holy book says A Little Faith.

Vina Thanks for that clarification.

[Amber G.]

Kanson,

Excellent post(s). It vividly shows the the bankruptcy of narrative often posted by some. Thanks.

And to return to the original post that started this discussion,

quote="marimuthu" >>One Noob question. What we have all seen is A-5 takeoff only. No one saw the travel path or the splash down. But when Dr.Avinash Chandar says it is a grand success, we joyfully agree. Also in Pok-2 we all the the ground tremble only. No body saw anything else. But why question AK if he claims the POk-2 a grand success.<<

Err, maybe because even the IN is a witness to the splash down? And SFC folks and other folks witnesses the launch. So if the launch was successful and the splash down and explosion were witnessed it may just, just, qualify as a grand success.

OTOH, only AK and BARC claim that S-1 was a grand success. Does DRDO support that? And SFC concur?

Just as DRDO ONLY has the authority to comment on the success or failure of missiles, ONLY BARC has the authority and possess complete set of data, required expertise in working on that field and intimate knowledge of the device and the test as they are the one who planned the test, know the composition and as well as goal of those test, to call their test as success or failure.

Just as we have to believe DRDO on the success of these tests, we have to believe BARC on the success of POK 2 tests.

AK already mentioned at the end of the interview to Karan Thapar that the arsenal that was being questioned is already with the Command or words to that effect(interested ones can check the clip). That put to rest all noises like, are we going to field TN? are we going to mount TN in our missiles? is the warhead mounted is TN or just fission, etc

[SaiK]

It does not matter to double and triple emphasize on posts. The opinions and reflections don't change unless it is vivid by data... and I don't think we would get there. So, it is a mute point discussing on the yields. It would be better to look at future designs, and work on them. If we say, a 200kt is ready and rearing to get mated with MIRVs (btw, 2 years for this discussions to end), we shall be left with that uncertain minds.

[abhijitm]

One request. Please can we rename dhaga as A5 Tessy ICBM: New Capabilities, technologies, strategies?

Thanks.

[chackojoseph]

Merlin,

To put you at ease. There is no 3rd party verification and the tests were designed to do not allow other estimate it.

The thermo nuclear bomb has following stages 1) fission blast to generate the temperature. 2) then the nucleas joins to create thermo blast. We proved it.

Just that the full potential was not reached. Hence at higher KT we are supposed to be blind.

There are 2 schools of thought.

a) thinks that they can calibrate it with simulation
b) needs actual test needed for calibration.

[Suraj]

Just as DRDO ONLY has the authority to comment on the success or failure of missiles, ONLY BARC has the authority and possess complete set of data, required expertise in working on that field and intimate knowledge of the device and the test as they are the one who planned the test, know the composition and as well as goal of those test, to call their test as success or failure.

Just as we have to believe DRDO on the success of these tests, we have to believe BARC on the success of POK 2 tests.

The point is that they have more credibility and data when they claim success than you do when you claim it isn't. Unlike at POK 2, when those within the establishment and outside raised questions, there has been none with the Agni V test. Could there be in future ? Sure.

Further, I fail to see why an episode involving one set of entities (DAE/BARC) serves as a reason to assert a similar skepticism about a different organization (DRDO) and a different set of people who have nothing to do with POK 2. That would be like judging one poster by the actions of another - "oh look, he's a troll, so you must be too". What BARC/DAE did or didn't do 14 years ago has zero relevance to the Agni-V test of two weeks ago.

Further, unlike any of the nuclear tests and in particular the claimed 2-stage thermonuclear fizzle, the Agni V isn't even close to being the first missile they've tested. Not only that, even technologies within the A-V were previously flight tested in the A-III or A-IV .

There's nothing wrong with asking questions when doubt is reasonable. I'm asking what your basis for reasonable doubt is. You've provided none whatsoever, beyond 'we can't trust the DRDO' followed by much handwaving. If your line of thinking is just that DRDO, DAE, BARC and any other govt org are incompetent and cannot be trusted under any circumstances, that's fine, but remember that merely amounts to your personal opinion.

[Anujan]

The civvie higher ups know what happened. Pok 2 was monitored by civilian intel agencies too. Will be interesting to track our missile developments to see the line of thinking vis-a-vis the bum.

[chackojoseph]

Suraj,

Kason is technically right. They are designated govt agencies to manage their affairs. So, if they say, they are right.

[Prem Kumar]

My 2 naya-paisa & apologies for the OT: I get the impression that Kanson's point is this "Since we are ready to believe A-5 test is a success based on DRDO's words, we should similarly believe Pok-2 TN was a sizzle & we have proven TNs, based on BARC's words".

Kanson: correct me if I am wrong because I dont want to burn a strawman.

Kanson is right in terms of "who" can ultimately make the assertion (though there are some nuances in the Pok-2 case). But here is where the above analogy falls apart - even if we assume that the TN was a sizzle:

a) DRDO is not saying that A-V is ready to be deployed. Its going to take 2 more tests before deployment, as per the recommendations of some gentleman's committee (I forget his name). Post Pok-2, if we claim we have deployed TNs, there is skepticism about the reliability of the device because 1 test is too little

b) DRDO is not claiming that A-V is a 10000 KM ICBM. If they did that, there will be skepticism because they havent tested A-V to that range. But after Pok-2, if AK or anyone else claims that the deployed TN bums have a yield of 250KT, there is once again justifiable skepticism

Neither of the above are an indictment of AK's integrity or a question of trust. These are just established scientific principles on repeatability of experiments & extrapolation of results.

Also, everyone is aware that the decision to test only 40KT and 3 bums at the same time was made by the scientists because they were under extreme pressure to collect as much data within as few tests as possible. Hats off to them for what they accomplished under the circumstances. However, here is where our political leadership failed us spectacularly. Their only job was to absorb the international pressure, show some balls and tell the world that we will conduct a series of open ended tests till we are satisfied. That's what leaders are supposed to do - provide air-cover. Instead they demonstrated that they have "half a ball". And they thought they could finesse their way out of the sanctions regime - instead of just saying "up yours". Result - we have a miserable deterrence and endless questions.

[SaiK]

well technically they are wrong to prove it without validation process.
and politically they are right to say what ever they want to say.

now, politically they can be correct to say - we shall not share information.

[Suraj]

Kason is technically right. They are designated govt agencies to manage their affairs. So, if they say, they are right.

Err, that's what I said too. Sounds like we're all just talking past each other here

[member_20317]

Merlin,

To put you at ease. There is no 3rd party verification and the tests were designed to do not allow other estimate it.

The thermo nuclear bomb has following stages 1) fission blast to generate the temperature. 2) then the nucleas joins to create thermo blast. We proved it.
Just that the full potential was not reached. Hence at higher KT we are supposed to be blind.

Chako bhai you may be wrong here just as people on the other end of the spectrum.

1) The first stage has hard x rays which are accompained by high temperatures. Temperature may actually be a problem.

2) The kind of x-rays to which the carbon foam would react by becoming a plasma, which would perhaps feed the walls with further x-rays and which in turn would feed the foam. The words adabatic process gets mentioned very often in these processes. The following has a nice interactive graphic on the same.
http://buphy.bu.edu/~duffy/semester1/c2 ... c_sim.html
An adiabatic process is a process in which no heat is transferred. This can happen if the process happens so quickly that there is no time to transfer heat, or if the system is very well insulated from its surroundings.

This stage (if it can be called that) is where I think Arun_S et al were pointing out at the fag end of his BR career. Because this stage is where moving fluids cause some kind of instabilites to develop which hinder the smoothness of the process.

3) at some point this would lead the secondary to ablate material creating enough pressure to implode the secondary which has its own physics at temperatures and pressures and neutron populations, which could be different from the chemical explosive driven physics of the primary.

Even in places where ‘non-linear ___’ was not pointed out there are instabilities that may themselves behave very differently from the lesser pressures of the chemical explosive driven implosions.
So basically more then enough places to go wrong.
Chako ji I personally believe even Bakistan can make a thermonuke which should work in the first attempt. Whether its going to be deliverable or even predictable is something I don’t have a view on.

There are 2 schools of thought.

a) thinks that they can calibrate it with simulation
b) needs actual test needed for calibration.

Well a business should at least be made to run on an excel sheet if at all some money is to be thrown at it. But has the spreadsheet wala done any business or will be successful if he gets the money is a question that stays even if only in the realm of speculation.