Recent Interview with Pakistani Nuclear scientist Dr.Samar Mubarakmand

[Zahoor Raja-Jani]

The entire RV is not made of carbon fiber, the small black color tip on the nose of the missile, thats made of 3D carbon-carbon. Its purpose is to withstand re-entry heat, rather than give stealthy features.
As I said before, counter-measures will arrive, all in good time.

Yes i want to confirm this from you for my friends who are talking about stealthy RV, since re entry heats up RV so much that any type of material can't help to hide I.R signatures.

 

[The Deterrent]

Yes i want to confirm this from you for my friends who are talking about stealthy RV, since re entry heats up RV so much that any type of material can't help to hide I.R signatures.

Exactly, its almost impossible to make a conventionally-shaped RV low observable, the re-entry heat signature simply cannot be reduced.

 

[Mrc]

Now that is something innovative (of sorts). What the Iranians have done here is figure out a way to not only stabilize the RV by using fins, but also maneuver it using the same fins, inside the atmosphere. We don't have anything like that, capable of maneuvering inside the amosphere. We either use fins (Ghaznavi/Shaheen-I) or spinning (Shaheen-IA/II/III, Ghauri) for stabilization, not maneuvering.

Only reason why iranians did it and we did not uptill now would be that there was no need for us to do this while iranians had reasons....

Otherwise i dont see a huge technological gap here that similar things xannot be adopted (if not already) by pakistan

Exactly, its almost impossible to make a conventionally-shaped RV low observable, the re-entry heat signature simply cannot be reduced.

Yes i want to confirm this from you for my friends who are talking about stealthy RV, since re entry heats up RV so much that any type of material can't help to hide I.R signatures.

To kill a nuclear rv u need a direct hit....
The radar need to track it accurately to get an interceptor close enough ...radar cannot track IR signature... u may know its there but u wont be able to hit it unless u can see it on radar....

Also chaff dispensers will work brillianltly against terminal intercept...from what i read....

 

[amardeep mishra]

Thats not entirely accurate. RVs decelerate to less than Mach 4 during re-entry, so assuming that it will be travelling at Mach 15 till it detonates is flawed assumption.


Prithvi-II simulated target takes a very lofted trajectory, re entering at a much steeper angle, so the interception is more of a head-on one. What remains to be proven via a Agni-I/II test, is the interception of a smaller target (RV) at a much more lateral angle of re-entry.


There ins't anything like a stealth RV, as the missile can be detected easily in boost phase and tracking it from thereon is not difficult. Moreover, the RV shape cannot be optimized for RCS reduction, as it is constrained by the relevant aerodynamics.

Hi dear @The Deterrent Deterrent
I wrote an entire python code to answer a lot of questions that usually crop up in reference to ICBM trajectory and I wish to summarize my findings.

I first wrote a python function couple of months back to simulate the re-entry of various RVs.But it had certain limitations as i couldnt model the atmosphere accurately.Today morning however i modified my old code to accommodate density changes in atmosphere all the way upto 80kms!I have considered both isothermal regions of the atmosphere and temperature gradient layers as well.And here is the result.
I wish to make it clear at the very outset that i have assumed a ballistic coefficient for Shaheen missile to be 800lbf/ft^2 or ~3900kg/m^2. I assumed a re-entry flight path angle to be 12 degrees-because thats the angle most of the missile RVs usually splash down into atmosphere at roughly 80kms.I have also assumed an initial velocity of close to 12machs for Shaheen.My analysis starts at 76kms.
Couple of things one can infer from this analysis-
1)The velocity with which Shaheen will hit earth(or lets say reach 500m above earth-because thats where detonation takes place) is roughly ~(1200m/s) or 3.5Machs(the actual velocity will be pretty close to that).This results is a heavy function of the beta(ballistic coefficient) of the RV.I ran my code with 3 different values of ballistic coefficient- 3900,14628 and 24380.2kg/m^2 to find different answers! In the first case i.e beta~3900,the terminal velocity was close to 3.5M,whereas in the case of modern ICBMs with beta values close to 24000-25000kg/m^2,the terminal velocity or the velocity with which it will hit earth came out to be close to 12M!
2)Secondly and perhaps equally important conclusions that can be drawn from this analysis is the time taken by the RV to hit earth from the point of entering atmosphere.Again for a shaheen type RV,this figure came out to be slightly above 90s.
3)Thirdly the downrange covered by the RV from the point of entering atmosphere was close to 350kms!

Kindly note that this analysis depends on the fact that Ballisitic coefficient of shaheen is 3900kg/m^2,a higher value of beta would yield a higher impact velocity

The indian bmd has never been tested against an rv descending from 600 kms...

They use non separating prithvi missile with 250 km range and 30 km maximum height ....

Hi dear @Mrc
It is correct that indian BMD hasnt been tested against an IRBM/ICBM descending from above 600kms.The earlier PDV used prithvi as the interceptor.However newly modified PDV is a different vehicle with complete structural changes.The mid-sections wings have been shifted way behind CG and so has tail changed as well.The seeker was also changed from active RF to IIR. In my view though,the most important change that was introduced in newly modified PDV was- replacement of liquid engine with solid one.The modified PDV is an EXO-ATMOSPHERIC interceptor that can reach an altitude of 150kms- or at least thats what the DRDO research papers claim.It has already been tested upto an altitude of 120kms!

 

[Zahoor Raja-Jani]

Only reason why iranians did it and we did not uptill now would be that there was no need for us to do this while iranians had reasons....

Otherwise i dont see a huge technological gap here that similar things xannot be adopted (if not already) by pakistan




To kill a nuclear rv u need a direct hit....
The radar need to track it accurately to get an interceptor close enough ...radar cannot track IR signature... u may know its there but u wont be able to hit it unless u can see it on radar....

Also chaff dispensers will work brillianltly against terminal intercept...from what i read....

Sir i am not expert in this field hence have very basic knowledge but i can say that you can track and hit R.V (not MaRV) with I.R lock down. Further i would like @The Deterrent to shed light on this.

 

[JamD]

Sir i am not expert in this field hence have very basic knowledge but i can say that you can track and hit R.V (not MaRV) with I.R lock down. Further i would like @The Deterrent to shed light on this.

What @Mrc is referring to I think is this:

 

[amardeep mishra]

The entire RV is not made of carbon fiber, the small black color tip on the nose of the missile, thats made of 3D carbon-carbon. Its purpose is to withstand re-entry heat, rather than give stealthy features.
As I said before, counter-measures will arrive, all in good time.

Hi dear @The Deterrent
I am afraid you're mistaken here,all indian strategic missiles-particularly the AGNI have complete RV made up of heat resistant carbon fibres and not just the the tip.That is the trend everywhere,isnt it?

What @Mrc is referring to I think is this:
View attachment 306106

Hi dear @JamD
Well,as you'd know from a purely control engineering perspective,a proportional guidance scheme is mathematically expressed as-
al=-k*v*lambda'
where al=lateral acceleration(acceleration perpendicular to the velocity vector of the vehicle)
k=gain
v=relative velocity between missile and the target
labda'=rate of change of line of sight angle.
What we basically aim to do in PG schematic is- we drive the line of sight angle to a constant value by manipulating lateral accleration. Simple geometry would prove that a constant line of sight angle would result in a collision.Now in the case of IIR seeker,the relative velocity information is implicitly or indirectly estimated from the rate of growth of pixels.Centroid tracking along with image correlation are almost always used simultaneously.

 

[JamD]

Hi dear @JamD
Well,as you'd know from a purely control engineering perspective,a proportional guidance scheme is mathematically expressed as-
al=-k*v*lambda'
where al=lateral acceleration(acceleration perpendicular to the velocity vector of the vehicle)
k=gain
v=relative velocity between missile and the target
labda'=rate of change of line of sight angle.
What we basically aim to do in PG schematic is- we drive the line of sight angle to a constant value by manipulating lateral accleration. Simple geometry would prove that a constant line of sight angle would result in a collision.Now in the case of IIR seeker,the relative velocity information is implicitly or indirectly estimated from the rate of growth of pixels.Centroid tracking along with image correlation are almost always used simultaneously.

Yes, of course. We have met before @amardeep mishra, I think you forgot :p Fellow controls engineer here haha. I was trying to answer the nontechnical member's query without going into proportional guidance and each seeker's subtleties too much.

 

[amardeep mishra]

We don't have anything like that, capable of maneuvering inside the amosphere. We either use fins (Ghaznavi/Shaheen-I) or spinning (Shaheen-IA/II/III, Ghauri) for stabilization, not maneuvering.

Hi,
I thought the pitch correction maneuvers in pakistani strategic missiles inside the atmosphere are provided by jet vanes.The tail fins are indeed for stabilization.
As for iranian strategic missiles,i fail to see how they are impressive when they still use external surfaces for both stabilization and maneuvering. Modern trend is to use flex nozzles that are either gimbaled or have servo-mechanism.

Yes, of course. We have met before @amardeep mishra, I think you forgot :p Fellow controls engineer here haha. I was trying to answer the nontechnical member's query without going into proportional guidance and each seeker's subtleties too much.

yes yes! i remember you! so how was your guidance paper man?here i am writing a python code for my raspberry pi to control servo motor based on a IMU 6050 feedback

 

[LeGenD]

Pakistani missiles having "guided" warheads that can change directions as they reenter the atmosphere at super high speeds. And his absolute confidence that these missiles will beat "any" ABM system (even if he meant only indian ABMs..I kinda found all that a bit new)

I don't think that any Pakistani scientist is in the position to make such a claim. Nor should one.

 

[JamD]

yes yes! i remember you! so how was your guidance paper man?here i am writing a python code for my raspberry pi to control servo motor based on a IMU 6050 feedback

Phew! lol It went pretty well actually, thanks for asking Oh cool, I haven't been in touch with hardware level stuff in a while. I am planning to though again (I feel empty inside). Let's not derail this thread too. Tata!

 

[Zahoor Raja-Jani]

I don't think that any Pakistani scientist is in the position to make such a claim. Nor should one.

If you check first post a video Mr. Samar Mumbarak claims the same that our missiles are terminally guided and can change direction in mid course any time.

 

[Djinn]

Pakistani missiles having "guided" warheads that can change directions as they reenter the atmosphere at super high speeds. And his absolute confidence that these missiles will beat "any" ABM system (even if he meant only indian ABMs..I kinda found all that a bit new)

I didn't watch the interview, but from your post i think he was referring to the MARV tech (Maneuverable reentry vehicle). Has been around for decades not surprised that Pakistan has incorporated it into it's ballistic missiles.

 

[Mrc]

This re-entry vehicle is unlike that of the Shaheen I in that it has four moving delta control fins at the rear and small solid/liquid-propellant side thrust motors, which are used to orient the re-entry vehicle after the booster stage is depleted or before re-entry to improve accuracy by providing stabilization during the terminal phase. This can also be used to fly evasive manoeuvres, making it problematic for existing anti-ballistic missile (ABM)systems to successfully intercept the missile. The Shaheen II warhead may change its trajectory several times during re-entry and during the terminal phase, effectively preventing ABM radar systems from pre-calculating intercept points. The re-entry vehicle is also stated to utilise a GPS satellite guidance system to provide updates on its position, further improving its accuracy and reducing the CEP.[5][6]


This is copied and pasted from wikipedia..seems to be exactly what dr mand is saying in the video.

And also shaheen series has much lower cep than iranian emaad (actually 10 times less)..

 

[LeGenD]

If you check first post a video Mr. Samar Mumbarak claims the same that our missiles are terminally guided and can change direction in mid course any time.

Terminal guidance comes into play during the Terminal phase of the flight to guide the warhead towards its destination with good accuracy.

Modern American ABM systems have the capability to intercept a Ballistic Missile during both Midcourse and Terminal phases of its flight and are equipped with Terminal guidance systems of their own. Moreover, the interceptor missiles do not just depend upon their on-board guidance systems to hone-in towards the target, they take cues from the entire surveillance setup (ranging from radar systems on the ground to satellites in space) to track the movement of the target in real-time.

So even if a Ballistic Missile is changing its direction mid-flight, it cannot escape or evade a modern interceptor unless it is relatively much faster.

In the end, it comes down to what kind of foe we are dealing with. India doesn't have the capability to intercept Shaheen series ballistic missiles at the moment but US is a much more capable foe.