BMD tested successfully

[Blue Marlin]

got a pic of the missile? is it the prahar based or the privth based?

 

[Safriz]

got a pic of the missile? is it the prahar based or the privth based?

Prithvi based.
I got the pic but won't post. Must be done by some Indian

But PDV covers most if not all of current Pakistan options (when PDV system is ramped up), given I believe Pakistan has no true MIRV (Ababeel argument does not change anything if one looks at the math), much less countermeasures for them.

Counterforce and BMD will be staggered and layered by India in the years to come.

What exactly is a "True MIRV"?

 

[Nilgiri]

What exactly is a "True MIRV"?

One that doesn't reduce the range of a parent 2700km range missile by just 500 km, implying payload increase by my estimates of around 20%.

 

[Safriz]

One that doesn't reduce the range of a parent 2700km range missile by just 500 km, implying payload increase by my estimates of around 20%.

May i point out that rules change in case of MIRV.
The stated range is the Missile's range not the RV range.
The RV range is always classified.

Although i didnt really understand what you are saying but i think you are implying that since Ababeel is based on Shaheen-3 of 2750 Km range and Ababeel declared range is 2200Km , there is a reduction of range?

But but the Payload increase is at least 3 times as Ababeel carries at least 3 Shaheen-3 sized warheads. Then the weight of Post boost vehicle which is quite large.
There is also a third stage which is brand new and presumably liquid fueld . Thats why i dont believe in the humbug of a three stage 20+ meter tall missile being of just 2200 Km range.
Although like i said in case of MIRV range is stated in a different way. The RVs can travel much farther depending on the release angle.

 

[Nilgiri]

The stated range is the Missile's range not the RV range.
The RV range is always classified.

The stated missile (system) range always governs the total system's overall kinetic profile given the energy is imparted during the launch phase and at no other point (thus creating a ballistic trajectory). Post apogee boosting is focused (when done) on trajectory orientation rather than total energy increase.

Re entry ballistics of RV's (and potential spread pattern) are thus still governed by this overall kinetic profile.

http://www.rand.org/content/dam/rand/pubs/research_memoranda/2008/RM3475.pdf

Besides such boost systems (to add the I to MRV) would add even more mass (and thus mass penalty on supposed countermeasures) and a sub-5000 km range missile would not have the throw-weight (without looking insanely awkward) for all of it.

There's a reason why US and USSR or any other major power didn't MIRV their non-ICBMs. There are severe penalties that actually degrade what the system(sub 5000km) is optimised for all together. It is simply much more efficient to churn out more cruise missiles to be honest. So something is definitely up with the ababeel claim....if the range was far lower than 2200 km, it would start to become believable in pure total energy standpoint.

 

[Blue Marlin]

Prithvi based.
I got the pic but won't post. Must be done by some Indian

dont be shy.

 

[Safriz]

The stated missile (system) range always governs the total system's overall kinetic profile given the energy is imparted during the launch phase and at no other point (thus creating a ballistic trajectory). Post apogee boosting is focused (when done) on trajectory orientation rather than total energy increase.

Re entry ballistics of RV's (and potential spread pattern) are thus still governed by this overall kinetic profile.

http://www.rand.org/content/dam/rand/pubs/research_memoranda/2008/RM3475.pdf

Besides such boost systems (to add the I to MRV) would add even more mass (and thus mass penalty on supposed countermeasures) and a sub-5000 km range missile would not have the throw-weight (without looking insanely awkward) for all of it.

There's a reason why US and USSR or any other major power didn't MIRV their non-ICBMs. There are severe penalties that actually degrade what the system(sub 5000km) is optimised for all together. It is simply much more efficient to churn out more cruise missiles to be honest. So something is definitely up with the ababeel claim....if the range was far lower than 2200 km, it would start to become believable in pure total energy standpoint.

The stated missile (system) range always governs the total system's overall kinetic profile given the energy is imparted during the launch phase and at no other point (thus creating a ballistic trajectory). Post apogee boosting is focused (when done) on trajectory orientation rather than total energy increase.

Re entry ballistics of RV's (and potential spread pattern) are thus still governed by this overall kinetic profile.

http://www.rand.org/content/dam/rand/pubs/research_memoranda/2008/RM3475.pdf

Besides such boost systems (to add the I to MRV) would add even more mass (and thus mass penalty on supposed countermeasures) and a sub-5000 km range missile would not have the throw-weight (without looking insanely awkward) for all of it.

There's a reason why US and USSR or any other major power didn't MIRV their non-ICBMs. There are severe penalties that actually degrade what the system(sub 5000km) is optimised for all together. It is simply much more efficient to churn out more cruise missiles to be honest. So something is definitely up with the ababeel claim....if the range was far lower than 2200 km, it would start to become believable in pure total energy standpoint.

This research paper is from 1963 and many things have changed since then.
Read my comment again AS I ADDED MORE.

dont be shy.

 

[Nilgiri]

Although i didnt really understand what you are saying but i think you are implying that since Ababeel is based on Shaheen-3 of 2750 Km range and Ababeel declared range is 2200Km , there is a reduction of range?

What im saying is the same* "juice" you impart to a higher mass system (keeping all else the same*) will reduce the range right?

So if you back track the calculation using ballistic equations, you can determine the mass ratio of the two systems.

When I did it for shaheen III (parent) and ababeel (child), I got the payload to come to about 80% for shaheen III compared to ababeel. It has to be at least 50% (i.e so it can be multiplied by 2 to get 100% - and a claim can be made for 2 warheads of same size or 3 warheads with miniaturisation factor of 0.66) for me to think seriously on it further.

*There is the argument that the 2nd stage has been lengthened a bit, but I don't see it being enough, though maybe you can tag me someone on your side that has done a length/fuel isp/added energy conversion. By optics, it doesn't look to be enough in my opinion.

But but the Payload increase is at least 3 times as Ababeel carries at least 3 Shaheen-3 sized warheads. Then the weight of Post boost vehicle which is quite large.

Yeah that physically does not make sense. 3 warheads of the same mass as the one in shaheen III would not reduce the range of the system by just 500 km. Payload fraction (m1/m2) would have to be 33%, that corresponds to:

m1/m2 = 0.33

(v2/v1)^2 = 0.33

Using v1 = 5.2 km/s for shaheen III (given max range of 2750 km)

V2 would be about 3 km/s.

That corresponds to a max range of about 900 km.

This among other reasons is why MIRVs simply are not done for sub-5000 km ranges, the mass/energy envelopes simply are not there.

There is also a third stage which is brand new and presumably liquid fueld . Thats why i dont believe in the humbug of a three stage 20+ meter tall missile being of just 2200 Km range.

If you are saying the performance of shaheen III parent is under-reported to start with, thats whole different argument that needs separate topic (and bring in fuel types and Isp calculation factors etc). I'm just going with what is released officially.

Although like i said in case of MIRV range is stated in a different way. The RVs can travel much farther depending on the release angle.

Thats not what I am disputing. I'm talking about the whole energy of the system being way off when compared to the numbers published about the corresponding ranges.

This research paper is from 1963 and many things have changed since then.
Read my comment again AS I ADDED MORE.

Thats not the point. Basic physics are the same no matter what time period we are talking about. We still use the ballistic equations derived by Newton for that very reason....and he dates from a time well before 1963

 

[Blue Marlin]

View attachment 376331

thanks
its based on the privth
paistan can do the same and base it of the abdali

 

[Safriz]

What im saying is the same* "juice" you impart to a higher mass system (keeping all else the same*) will reduce the range right?

So if you back track the calculation using ballistic equations, you can determine the mass ratio of the two systems.

When I did it for shaheen III (parent) and ababeel (child), I got the payload to come to about 80% for shaheen III compared to ababeel. It has to be at least 50% (i.e so it can be multiplied by 2 to get 100% - and a claim can be made for 2 warheads of same size or 3 warheads with miniaturisation factor of 0.66) for me to think seriously on it further.

*There is the argument that the 2nd stage has been lengthened a bit, but I don't see it being enough, though maybe you can tag me someone on your side that has done a length/fuel isp/added energy conversion. By optics, it doesn't look to be enough in my opinion.



Yeah that physically does not make sense. 3 warheads of the same mass as the one in shaheen III would not reduce the range of the system by just 500 km. Payload fraction (m1/m2) would have to be 33%, that corresponds to:

m1/m2 = 0.33

(v2/v1)^2 = 0.33

Using v1 = 5.2 km/s for shaheen III (given max range of 2750 km)

V2 would be about 3 km/s.

That corresponds to a max range of about 900 km.

This among other reasons is why MIRVs simply are not done for sub-5000 km ranges, the mass/energy envelopes simply are not there.



If you are saying the performance of shaheen III parent is under-reported to start with, thats whole different argument that needs separate topic (and bring in fuel types and Isp calculation factors etc). I'm just going with what is released officially.



Thats not what I am disputing. I'm talking about the whole energy of the system being way off when compared to the numbers published about the corresponding ranges.



Thats not the point. Basic physics are the same no matter what time period we are talking about. We still use the ballistic equations derived by Newton for that very reason....and he dates from a time well before 1963

Here is an accurate comparison of size between Shaheen-3 , Shaheen-1A and Ababeel. I did size comparison of these three missiles as all of them use the same warhead.
You can see that Shahee-3 and Ababeel use exactly the same first and second stages.
But Ababeel also has a third stage above the second stage?
This third stage has no cable runners so it is most probably liquid fueled which are very efficient in space and generate much larger acceleration due to being able to burn for longer, in space i mean.
The extra weight you mention of PBV and three warheads will be compensated by this third stage.
Hope this clears your confusion?

 

[Nilgiri]

This third stage has no cable runners so it is most probably liquid fueled which are very efficient in space and generate much larger acceleration due to being able to burn for longer, in space i mean.

And have there been any specs regarding this stage's dimensions (at least length) in any discussion? From that I can estimate the fuel contained within it (assuming best case scenario liquid isp), after accounting for engine length first.

This is what I meant earlier by optical visual. It doesn't look beefed up/long enough to me from calculations I have done on the matter when comparing rocket families...but point me to some numbers/calculations any of you have done (sorry I didn't participate in any of the ababeel threads)....or at least what the assumed dimension of this new stage is like (I don't have reference of what size this rocket is).

 

[Safriz]

thanks
its based on the privth
paistan can do the same and base it of the abdali

For us mounting a nuclear weapon on BMD will make more sense.

And have there been any specs regarding this stage's dimensions (at least length) in any discussion? From that I can estimate the fuel contained within it (assuming best case scenario liquid isp), after accounting for engine length first.

This is what I meant earlier by optical visual. It doesn't look beefed up/long enough to me from calculations I have done on the matter when comparing rocket families...but point me to some numbers/calculations any of you have done (sorry I didn't participate in any of the ababeel threads)....or at least what the assumed dimension of this new stage is like (I don't have reference of what size this rocket is).

Thats why i streessed on the word "Space" in my comment?
Once missile is out of Atmosphere and in space it doesn't need massive thrust to gain speed. A slow burning liquid fueld engine can gradually increase speed and hence range.
About Dimensions of this stage , no we didnt calculate but we did calculate the the length of PBV. Thats 5 meters from the end of third stage where the wide section begins to the top of the cone.
Also i have a hunch that the third stage doesn't separate from PBV and is a part of PBV.

 

[Nilgiri]

Thats why i streessed on the word "Space" in my comment?
Once missile is out of Atmosphere and in space it doesn't need massive thrust to gain speed. A slow burning liquid fueld engine can gradually increase speed and hence range.

Um the physics of energy addition doesnt suddenly change from earth to space, given I have put the envelope assumption (for best case scenario) as no air resistance anywhere (this actually would thus give higher altitude achieved etc), to simplify the assumptions and calculations already.

About Dimensions of this stage , no we didnt calculate but we did calculate the the length of PBV. Thats 5 meters from the end of third stage where the wide section begins to the top of the cone.

Like I said, we can tackle PBV after. PBV delta V, delta M additions are designed (by very concept of PBV) to be negligible....given they are done just after apogee. Whatever is contained below the warhead fairing and above the actual stages has many possibilities, not just PBV. We can run with a PBV conceptually (once basic total energy envelope is established), but thats not the angle I am going at here (yet).

Are there any pictures anywhere giving what you guys think is the PBV (and more importantly what represents 5 metres)? From that I can try guess the 3rd stage length....subtract an assumed engine length from it...and using Isp of best case liquid fuel, can tell you quite quickly whether the energy addition (under vacuum like I have always assumed) is enough for the claimed system parameters.

 

[Safriz]

Um the physics of energy addition doesnt suddenly change from earth to space, given I have put the envelope assumption (for best case scenario) as no air resistance anywhere (this actually would thus give higher altitude achieved etc), to simplify the assumptions and calculations already.



Like I said, we can tackle PBV after. PBV delta V, delta M additions are designed (by very concept of PBV) to be negligible....given they are done just after apogee. Whatever is contained below the warhead fairing and above the actual stages has many possibilities, not just PBV. We can run with a PBV conceptually (once basic total energy envelope is established), but thats not the angle I am going at here (yet).

Are there any pictures anywhere giving what you guys think is the PBV (and more importantly what represents 5 metres)? From that I can try guess the 3rd stage length....subtract an assumed engine length from it...and using Isp of best case liquid fuel, can tell you quite quickly whether the energy addition (under vacuum like I have always assumed) is enough for the claimed system parameters.

Here.
The bold numbers represent calculations if the Stage 1 and 2 are from shaheen-3 which i assume are.
The red canopy has been divided into two sections as thats biconical. The bottom cone is two meter tall as thats the length of Shaheen-3 warhead. The top cone is 1.4 meter tall. Total cone height is 3.4 meters (written in red blue font)
The wide white section below the cone was taken as the Post boost vehicle which is 1.74 meters long.
Total length of white part along with red canopy is
3.4 + 1.74 = 5.14 meters.
Width is 1.8 meters.

In case you are wondering whats the small red numbers. Thats the measurements we did while considering the first and second stages to be the 1.4 meter wide shaheen-2 stages which was not the right assumption.
Calculation was originally done by @JamD

 

[Nilgiri]

Here.
The bold numbers represent calculations if the Stage 1 and 2 are from shaheen-3 which i assume are.
The red canopy has been divided into two sections as thats biconical. The bottom cone is two meter tall as thats the length of Shaheen-3 warhead. The top cone is 1.4 meter tall. Total cone height is 3.4 meters (written in red blue font)
The wide white section below the cone was taken as the Post boost vehicle which is 1.74 meters long.
Total length of white part along with red canopy is
3.4 + 1.74 = 5.14 meters.
Width is 1.8 meters.

In case you are wondering whats the small red numbers. Thats the measurements we did while considering the first and second stages to be the 1.4 meter wide shaheen-2 stages which was not the right assumption.
Calculation was originally done by @JamD

Ok thanks. I have some other work to do now. I will post my envelope calculations later (incl) 3rd stage and we can discuss it later.