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mist_consecutive

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DRDO flags off first Varunastra, a heavy weight torpedo

Does this mean Varunastra is certified for active-service use, or just development is completed?
 

mist_consecutive

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It's only meant for ship submarine launched variant is under development.
Oh, is it? This article from Jan says it is also for Kilo-class submarines

It will be carried by Kolkata class, Rajput class and Delhi class destroyers. It will also be fitted on to Kamorta class corvettes and Talwar class frigates. Indian Navy's biggest fleet of Sindhughosh Class submarines will also carry Varunastra. The fleet currently has 9 operating vessels.

Didn't knew Varunastra is operational with Navy since Jan btw :)
 

mist_consecutive

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Varunastra is a ship launched torpedo. Can you put the same one on a sub?
I am not aware, what I can see is, the diameter of the torpedo & submarine torpedo tube are same.
What differs is the launch mechanism, and theoretically ship-launch torpedoes have to face a larger amount of stress while being launched (they are literally dropped from fast moving ship into water from height).

Any naval expert who can explain difference in ship-launch & submarine launch torpedos ?
 

Gautam Sarkar

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Any naval expert who can explain difference in ship-launch & submarine launch torpedos ?
I am no expert but allow me. Torpedo launch from subs have 2 common modes : Push-out & swim-out.

In Push-out mode the torpedo is pushed out using gas pressure and in swim-out mode the torpedo tube is flooded & then the torpedo swims out of the tube using it own power. Both modes have their own advantages & dis-advantages.

These is a sub version of the Varunastra under development named "Takshak".
 

mist_consecutive

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I am no expert but allow me. Torpedo launch from subs have 2 common modes : Push-out & swim-out.

In Push-out mode the torpedo is pushed out using gas pressure and in swim-out mode the torpedo tube is flooded & then the torpedo swims out of the tube using it own power. Both modes have their own advantages & dis-advantages.

These is a sub version of the Varunastra under development named "Takshak".
But why ship-launched Varunastra cannot be launched from Submarine?

Push-out mode using high-pressure water - same thing (but much safer) as using compressed air / explosive to push out torpedo from ship's launch tubes.

Swim-out mode - Even safer, as torpedo just moves on its own propulsion.
 

Gautam Sarkar

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But why ship-launched Varunastra cannot be launched from Submarine?
The ship launch of torpedoes require the torpedo to withstand a violent crash on to water. Then the torpedo swims out. To withstand that the torpedo's front end has to be reinforced which will add weight. Then you have to balance the weight to ensure the torpedo doesn't go nose down when in water.

No such problems exists for sub launched torpedoes. A ship launch Varunastra can be used form a sub in theory. But it will be inefficient. Space & weight is a premium on subs. Don't carry more than needed.

The sub version is likely going to be faster & longer ranged. It will have a 300KW battery instead of Varunastra's 250KW. It will have better RLGs too. The battery is a weight worth carrying & it is placed at the mid section so minimum problems with balancing.
 

Arihant Roy

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I am unable to fully comprehend some parts of the part three of the series by Tarmak . Although as usual its a great piece and emphasises on the right areas.

https://www.onmanorama.com/news/nat...fly-part-3.amp.html?__twitter_impression=true

The engineers are working on a new booster motor which will reduce aerodynamic forces and stresses induced on the HSTDV vehicle. This will allow the vehicle to be launched without any fairings. And the scientists are hoping to test this out in the very next launch.

As far I know, the stresses induced and aerodynamic forces are proportional to the booster speeds and the AoA of the cruise vehicle. Lower speeds means lower dynamic stresses and also lower skin drag . Lower kinetic heating .

So are you we to assume that the current booster takes hSTDV to a much higher Mach no during the later stages of flight regime. More than M6.5 . Which necessitates the use of the fairings . With a newer booster the peak velocity would be within the speed limits of the HSTDV. So a launch without any fairings can be attempted .


PS- This means our oballisticmissile tech from the late 90s and early 2000s and solid propellants science of that era is almost at par with other countries . We are so sophisticated that we need a new booster to be able to launch HSTDV without fairings . This is just awesome.


APJ KALAM is a legend of a legend. An ultra legend. If I bring a Dragon ball analogy here , HE is super saiyan four level.

He dreamt big on Hypersonics . He got his inspiration from Lord Krishna's lord 🙏 sudarshan chakra. He envisaged a hypersonic mother missile/drone which would carry smaller guided missiles warheads , take them to the general area, launch them and return back to base. Reusable .He was ahead of his time by 20-30 years . Even Uncle Sam with a defense budget that is almost two times of India's total budget doesn't have such a niche capability .
 

NAMICA

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I am unable to fully comprehend some parts of the part three of the series by Tarmak . Although as usual its a great piece and emphasises on the right areas.

https://www.onmanorama.com/news/nat...fly-part-3.amp.html?__twitter_impression=true

The engineers are working on a new booster motor which will reduce aerodynamic forces and stresses induced on the HSTDV vehicle. This will allow the vehicle to be launched without any fairings. And the scientists are hoping to test this out in the very next launch.

As far I know, the stresses induced and aerodynamic forces are proportional to the booster speeds and the AoA of the cruise vehicle. Lower speeds means lower dynamic stresses and also lower skin drag . Lower kinetic heating .

So are you we to assume that the current booster takes hSTDV to a much higher Mach no during the later stages of flight regime. More than M6.5 . Which necessitates the use of the fairings . With a newer booster the peak velocity would be within the speed limits of the HSTDV. So a launch without any fairings can be attempted .


PS- This means our oballisticmissile tech from the late 90s and early 2000s and solid propellants science of that era is almost at par with other countries . We are so sophisticated that we need a new booster to be able to launch HSTDV without fairings . This is just awesome.


APJ KALAM is a legend of a legend. An ultra legend. If I bring a Dragon ball analogy here , HE is super saiyan four level.

He dreamt big on Hypersonics . He got his inspiration from Lord Krishna's lord 🙏 sudarshan chakra. He envisaged a hypersonic mother missile/drone which would carry smaller guided missiles warheads , take them to the general area, launch them and return back to base. Reusable .He was ahead of his time by 20-30 years . Even Uncle Sam with a defense budget that is almost two times of India's total budget doesn't have such a niche capability .
Then HSTDV would require canister for storage if I am not wrong similar technology will be used in our hypersonic missile too as it will be also launched without fairings.

Regarding abdul kalam dream I think he was talking about avatar.
 

SavageKing456

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Then HSTDV would require canister for storage if I am not wrong similar technology will be used in our hypersonic missile too as it will be also launched without fairings.

Regarding abdul kalam dream I think he was talking about avatar.
What exactly is avatar?
Is it one of our reusable shuttle type vehicle?
 

Arihant Roy

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Then HSTDV would require canister for storage if I am not wrong similar technology will be used in our hypersonic missile too as it will be also launched without fairings.

Regarding abdul kalam dream I think he was talking about avatar.
There is no relation between canisters for storage and fairings used to encapsulate the vehcle from the outside pressures and stresses. Both mechanical and thermal.

You require a certain environment for storage of such articles. And missiles . And bombs.Temp, humidity needs to be maintained within a certain range .
 

Arihant Roy

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The Astra mk2 will use the dual pulse propulsion module of LRSAM . The motor will be modified to fit the Astra mk2 missile airframe . Remember that DRDO had developed the propulsion block including the TVC vanes of LRSAM.

The guidance , rf fuse and two way data linksseekers will be ported from Astra mk1. So, we will be seeing Astra mk1 enter service within a very short time span .

Also remember that the good ACM had spoken multiple times on how Astra was quickly operationalised the moment it completed its series of user trials at multiple forums and conferences . He explicitly said the same at the latest defense attache conclave organised by Nitin Gokhale and Bharat shakti .

Since the Astra missile initially used a newer upgrades variant of the 9B1348 seeker , integration with Su30MKI's Bars and the associate fire control system became easier. The DARE MC also helped to fasten up things . That's the advantage of having homegrown systems and subsystems . You can mix and match things in a much easier simple manner without having to run to the OEM and persuade them to provide you with the required codes and algos.

The similarity of Astra mk2 and LRSAM in the propulsion part will also help to bring down unit costs. Same applies to the seekers .
 
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