DRDO, PSU and Private Defence Sector News

[Tuco]

The missile is firing it's thrusters on the nose section while it has still not left the launcher so the above reasons are not valid

I had read about this many years ago, do not remember the reason. The very first test of this particular missile was a failure and to mitigate the problem the above contraption was introduced.

I got this from wiki "The first test for Agni III was conducted from Abdul Kalam Island (then known as Wheeler Island) off the Bhadrak coast on 9 July 2006.[6] The launch proved to be unsuccessful, with the missile falling into the sea off the coast of Odisha, short of reaching the target. According to DRDO, the failure was due to a first stage anomaly that was caused by recirculating hot gases entering the missile-base shroud and damaging the electronic components.[18] Indian Defence Minister Pranab Mukherjee reported it as "partial success" (a trade euphemism to indicate the test generated useful data for diagnosis and correction) as the missile was air-borne for only 5 minutes instead of the expected 15 minute"

 

[porky_kicker]

I had read about this many years ago, do not remember the reason. The very first test of this particular missile was a failure and to mitigate the problem the above contraption was introduced.

I got this from wiki "The first test for Agni III was conducted from Abdul Kalam Island (then known as Wheeler Island) off the Bhadrak coast on 9 July 2006.[6] The launch proved to be unsuccessful, with the missile falling into the sea off the coast of Odisha, short of reaching the target. According to DRDO, the failure was due to a first stage anomaly that was caused by recirculating hot gases entering the missile-base shroud and damaging the electronic components.[18] Indian Defence Minister Pranab Mukherjee reported it as "partial success" (a trade euphemism to indicate the test generated useful data for diagnosis and correction) as the missile was air-borne for only 5 minutes instead of the expected 15 minute"

No , not a valid reason because 1st stage is seperated from rest of missile by a vented interstage ( cage like structure )

What happens in 1st stage is restricted to 1st stage as can be noted in the post mortem , the gases in the 1st stage managed to penetrate the protective shroud in the 1st stage and damage the control systems there. Thereby 1st stage went kaboom . 2nd stage and PBV is not guilty .

And the gases are coming out of vents in the PBV ( nose section ) which is connected to 2nd stage. No direct connection to 1st stage

 

[porky_kicker]

I have a question

Say a missile (with 2 solid stages) is positioned in Hyderabad which say has the range to hit Beijing. It was initially feed with the coordinates to hit Beijing.

Later it was decided it was time to kill porkies . So coordinates of Lahore was feed.

And then fired

Lahore is less than half the distance to Beijing . And the missile has necessary fuel and therefore range to hit Beijing.

So the missile with 2 stage solid fuel which has just enough fuel to hit Beijing is now launched at Lahore.

Say 1st stage is used up to reach over Rajasthan , again say only 20% solid fuel of 2nd stage is used to reach over lahore.

What happens next ?

Remember once a solid fuel motor starts burning it doesn't stop untill it completely burns out .

And so won't the missile overshoot lahore since there is still 80% of solid fuel still left and thrust will continuously be produced till burnout ?

Again remember no separation of stages or payload is possible when the adjoining stage is producing thrust

How will this problem be overcomed in the missile ?

The answer to the above problem will probably be the answer to the below problem

 

[porky_kicker]

Now i will take a long break from dfi, had it coming lol

 

[fire starter]

I have a question

Say a missile (with 2 solid stages) is positioned in Hyderabad which say has the range to hit Beijing. It was initially feed with the coordinates to hit Beijing.

Later it was decided it was time to kill porkies . So coordinates of Lahore was feed.

And then fired

Lahore is less than half the distance to Beijing . And the missile has necessary fuel and therefore range to hit Beijing.

So the missile with 2 stage solid fuel which has just enough fuel to hit Beijing is now launched at Lahore.

Say 1st stage is used up to reach over Rajasthan , again say only 20% solid fuel of 2nd stage is used to reach over lahore.

What happens next ?

Remember once a solid fuel motor starts burning it doesn't stop untill it completely burns out .

And so won't the missile overshoot lahore since there is still 80% of solid fuel still left and thrust will continuously be produced till burnout ?

Again remember no separation of stages or payload is possible when the adjoining stage is producing thrust

How will this problem be overcomed in the missile ?

The answer to the above problem will probably be the answer to the below problem

View attachment 41928

why our missiles have zig zag rod separating the stage isn't it very old technique

 

[fire starter]

I have a question

Say a missile (with 2 solid stages) is positioned in Hyderabad which say has the range to hit Beijing. It was initially feed with the coordinates to hit Beijing.

Later it was decided it was time to kill porkies . So coordinates of Lahore was feed.

And then fired

Lahore is less than half the distance to Beijing . And the missile has necessary fuel and therefore range to hit Beijing.

So the missile with 2 stage solid fuel which has just enough fuel to hit Beijing is now launched at Lahore.

Say 1st stage is used up to reach over Rajasthan , again say only 20% solid fuel of 2nd stage is used to reach over lahore.

What happens next ?

Remember once a solid fuel motor starts burning it doesn't stop untill it completely burns out .

And so won't the missile overshoot lahore since there is still 80% of solid fuel still left and thrust will continuously be produced till burnout ?

Again remember no separation of stages or payload is possible when the adjoining stage is producing thrust

How will this problem be overcomed in the missile ?

The answer to the above problem will probably be the answer to the below problem

View attachment 41928

so last stage is separated even before starting stages completed their burning to avoid overshoot this is the answer.

 

[porky_kicker]

why our missiles have zig zag rod separating the stage isn't it very old technique

Sir i am on leave now , most probably permanent leave.

 

[porky_kicker]

so last stage is separated even before starting stages completed their burning to avoid overshoot this is the answer.

Is it possible ?
Note what i wrote previously

Again remember no separation of stages or payload is possible when the adjoining stage is producing thrust

Answer is simple yet requires knowledge of solid fuel rocket motors, especially on how to stop producing thrust ( shut down the motor )

I have now taken VRS......................

 

[Chinmoy]

View attachment 41921

Why ?........................................................

That's the very reason why I proposed my theory regarding the vents.

Such event is common when you feed fuel to rockets during launch.

 

[Chinmoy]

why our missiles have zig zag rod separating the stage isn't it very old technique

Yes it is. In A5 too we are using the same technique, but with a difference.

 

[fire starter]

Yes it is. In A5 too we are using the same technique, but with a difference.

but modern missiles don't use it only porki and our missiles use this why don't we upgrade it.

 

[Chinmoy]

but modern missiles don't use it only porki and our missiles use this why don't we upgrade it.

Every multistage rockets use this in their interstage. Even our PSLV and GSLV does use this.

This is cost effective and easy to deploy rather then other mechanism.

 

[fire starter]

Every multistage rockets use this in their interstage. Even our PSLV and GSLV does use this.

This is cost effective and easy to deploy rather then other mechanism.

no modern ballistic missile uses smaller ,efficient and more reliable soft stage separation mechanism where bottom stage is separated by tiny pyrobolts .

 

[fire starter]

Every multistage rockets use this in their interstage. Even our PSLV and GSLV does use this.

This is cost effective and easy to deploy rather then other mechanism.

our k series missiles uses advance mechanism that's why they are compact,stronger and can be fitted in a submarine.

 

[Chinmoy]

no modern ballistic missile uses smaller ,efficient and more reliable soft stage separation mechanism where bottom stage is separated by tiny pyrobolts .

Now A5 makes use of pyrobolts, but when A3 was produced, we were in need of a system which could be cost effectively deployed en mass. So the separation bars was the way forward.

 

[Chinmoy]

our k series missiles uses advance mechanism that's why they are compact,stronger and can be fitted in a submarine.

Needs are different for both the missiles. Can't compare them. Separation bars has nothing to do with being compact or strong.

 

[fire starter]

Needs are different for both the missiles. Can't compare them. Separation bars has nothing to do with being compact or strong.

major disadvantage of zig zag separation is that it increases the length of missile and prone to pre mature separation/breaking due to g force.

 

[Chinmoy]

major disadvantage of zig zag separation is that it increases the length of missile and prone to pre mature separation/breaking due to g force.

Length of missile looks compact only superficially, not in reality. And those separator bars are not flimsy to break under high G.

 

[IndianHawk]

I have a question

Say a missile (with 2 solid stages) is positioned in Hyderabad which say has the range to hit Beijing. It was initially feed with the coordinates to hit Beijing.

Later it was decided it was time to kill porkies . So coordinates of Lahore was feed.

And then fired

Lahore is less than half the distance to Beijing . And the missile has necessary fuel and therefore range to hit Beijing.

So the missile with 2 stage solid fuel which has just enough fuel to hit Beijing is now launched at Lahore.

Say 1st stage is used up to reach over Rajasthan , again say only 20% solid fuel of 2nd stage is used to reach over lahore.

What happens next ?

Remember once a solid fuel motor starts burning it doesn't stop untill it completely burns out .

And so won't the missile overshoot lahore since there is still 80% of solid fuel still left and thrust will continuously be produced till burnout ?

Again remember no separation of stages or payload is possible when the adjoining stage is producing thrust

How will this problem be overcomed in the missile ?

The answer to the above problem will probably be the answer to the below problem

View attachment 41928

Missile will use lofted trajectory. Will go much higher for Lahore than in case of Beijing.

Anyway Pak specific missile are separate we aren't going to waste A3-4-5 on porkies.

 

[porky_kicker]

Missile will use lofted trajectory. Will go much higher for Lahore than in case of Beijing.

Anyway Pak specific missile are separate we aren't going to waste A3-4-5 on porkies.

No

Common misconception

Time of arrival is of utmost importance in real life target engagement

Lofted trajectory alerts enemies , prone to detection and importantly classification as a nuclear strike

Lofted trajectory complicates MIRV dispersal.

Etc

A3 is for both .