DRDO and PSU news and discussion

Okabe Rintarou

Regular Member
Joined
Apr 23, 2018
Messages
332
Likes
1,173
Country flag
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 .
Not the speed alone. I think this has more to do with the fact that during the ascent phase, in the troposphere, high air density causes higher pressure and temperature stresses on the HSTDV airframe. In order to circumvent this, the first test relied on enclosing the HSTDV in a payload fairing. In parallel, the structural dynamics of HSTDV flying naked atop a booster were continually studied. Now that study is complete and our boffins are ready to test HSTDV without a payload fairing, but the booster will now have to be custom designed (based on data from the structural dynamics study) so that the booster only picks up speed after reaching the stratosphere. Within the troposphere, it will have to fly at speed and AoA limits as dictated by the study. The design objective of this booster is different. The previous booster, which was a Agni 1 booster, was designed with the objective of minimizing the ascent time for the payload.

As for where we stood in terms of solid fuel tech in the 90s (or even today), its certainly not "at par" with the world. We don't have ultra-high burn rate propellants. The grain strength is a bottleneck. In fact, from what I know, the reason Shaurya missile was rejected initially and Pralay came about is that Army was not happy with the lower burn rate of Shaurya's propellant grains. World standard is much higher.
Look at the Russian A-235 Nudol missile.
Also look at THAAD.
We have a ways to go. But we are getting there. This is going to be indispensable for AD-1 and AD-2.

And for Dr. Kalam's dream of making reusable missiles, it might be his original thought, but its not as if he was the first one with that idea. Americans have been working on projects like Blackswift for a long time now.
 

NAMICA

Tihar Jail
Banned
Joined
Oct 29, 2020
Messages
1,279
Likes
6,631
Country flag
Not the speed alone. I think this has more to do with the fact that during the ascent phase, in the troposphere, high air density causes higher pressure and temperature stresses on the HSTDV airframe. In order to circumvent this, the first test relied on enclosing the HSTDV in a payload fairing. In parallel, the structural dynamics of HSTDV flying naked atop a booster were continually studied. Now that study is complete and our boffins are ready to test HSTDV without a payload fairing, but the booster will now have to be custom designed (based on data from the structural dynamics study) so that the booster only picks up speed after reaching the stratosphere. Within the troposphere, it will have to fly at speed and AoA limits as dictated by the study. The design objective of this booster is different. The previous booster, which was a Agni 1 booster, was designed with the objective of minimizing the ascent time for the payload.

As for where we stood in terms of solid fuel tech in the 90s (or even today), its certainly not "at par" with the world. We don't have ultra-high burn rate propellants. The grain strength is a bottleneck. In fact, from what I know, the reason Shaurya missile was rejected initially and Pralay came about is that Army was not happy with the lower burn rate of Shaurya's propellant grains. World standard is much higher.
Look at the Russian A-235 Nudol missile.
Also look at THAAD.
We have a ways to go. But we are getting there. This is going to be indispensable for AD-1 and AD-2.

And for Dr. Kalam's dream of making reusable missiles, it might be his original thought, but its not as if he was the first one with that idea. Americans have been working on projects like Blackswift for a long time now.
.
Agni series missiles are old now .we have catched up lot in terms of complex propellants, burn rate ,composite and casting.
 

Chinmoy

Senior Member
Joined
Aug 12, 2015
Messages
5,571
Likes
9,378
Country flag
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 .
20201123_160623.jpg
 

Arihant Roy

Senior Member
Joined
Jan 25, 2018
Messages
1,012
Likes
6,289
Country flag
Not the speed alone. I think this has more to do with the fact that during the ascent phase, in the troposphere, high air density causes higher pressure and temperature stresses on the HSTDV airframe. In order to circumvent this, the first test relied on enclosing the HSTDV in a payload fairing. In parallel, the structural dynamics of HSTDV flying naked atop a booster were continually studied. Now that study is complete and our boffins are ready to test HSTDV without a payload fairing, but the booster will now have to be custom designed (based on data from the structural dynamics study) so that the booster only picks up speed after reaching the stratosphere. Within the troposphere, it will have to fly at speed and AoA limits as dictated by the study. The design objective of this booster is different. The previous booster, which was a Agni 1 booster, was designed with the objective of minimizing the ascent time for the payload.

As for where we stood in terms of solid fuel tech in the 90s (or even today), its certainly not "at par" with the world. We don't have ultra-high burn rate propellants. The grain strength is a bottleneck. In fact, from what I know, the reason Shaurya missile was rejected initially and Pralay came about is that Army was not happy with the lower burn rate of Shaurya's propellant grains. World standard is much higher.
Look at the Russian A-235 Nudol missile.
Also look at THAAD.
We have a ways to go. But we are getting there. This is going to be indispensable for AD-1 and AD-2.

And for Dr. Kalam's dream of making reusable missiles, it might be his original thought, but its not as if he was the first one with that idea. Americans have been working on projects like Blackswift for a long time now.
You said the same thing in a roundabout manner with greater depth and details.

Like in order to alleviate the problem of heating at low altitudes , the speeds should be or rather the top speed reached should be less than Mach 6.8.
If you want to have lower heating at higher denisty air of troposphere, you need to keep your speeds low OR use fairings . Skin drag / aerodynamic heating is proportional to speeds and aoa . So the new booster will have a lesser top speed or peak velocity than Agni 1 booster .

In stratosphere you also have that heating problem but the magnitude is less due to lower density . I reckon the Agni 1 booster takes the RV to a much higher Mach no. Agni 1 RV has a reentry velocity of around 3 to 3.5 m/sec. The Agni 1 booster has to take the RV to a much higher velocity than what is required for the HSTDV . Because we wanted to save time, we cut some corners and used the Agni booster so as to validate the basic flight dynamics and scramjet operation of the HSTDV . The second flight was more of a proof of concept .

Now that we have successfully demonstrated them, we will proceed with a dedicated booster .

The A-235 is a dedicated Asat system. It will complement 53T6 Gazelle of A-135 in the eco atmospheric interceptor role.

Also check out the Gorgon nuke tipped interceptor . It is much faster than our Agni 1 or for that matter any Agni missile in its raw accel eration after launch . It's in the Thaad class in speeds and acceleration . Agni doesn't come close. Also for the Gazelle , do check out the exhaust colour. It's reddish. Unlike our creamish white . Gazelle and Gordon uses higher ISP,high burn rates for higher acceleration and top speeds.

We were not at par but we were close. Yes our burn rates weren't good but they were comparable to the ones used in Western ICBM. Western and Eastern interceptors used high burn rates propellants though.
 
Last edited:

Arihant Roy

Senior Member
Joined
Jan 25, 2018
Messages
1,012
Likes
6,289
Country flag
Hearing about Blackswift for the first time . Thanks for bringing it up. Happy to be able to learn new things from others .

Familiar with its cousin HTV-2 Falcon . DARPA.

Scientists and engineers on both sides have thought about similar vehicles before Kalam. But there isn't any program of record on hypersonic reusable drone in US. A black project may exist though.

' Those who know don't speak. And those who speak don't know. '
 

Arihant Roy

Senior Member
Joined
Jan 25, 2018
Messages
1,012
Likes
6,289
Country flag
Yes ,Indian Army has test fired the 450 km range variant of Brahmos missile from Trak island .


The missile was test fired at 10 am and hit its target with pin point accuracy in another island in the Andaman archipelago . This test marks the operationalisation of the 400+ km range variant by the Army.
 

Arihant Roy

Senior Member
Joined
Jan 25, 2018
Messages
1,012
Likes
6,289
Country flag
Multiple Brahmos tests to take place this week.

The first test is scheduled for today

https://m.timesofindia.com/india/in...issile-this-week/amp_articleshow/79380572.cms
Some important points to note here.

1. Work is going on a fast pace to induct and operationally deploy the 450 km range Brahmos missile. I reckon this successful test will pave the way for this.missile induction .

2. India and Russia is jointly working on a 800 km range super Brahmos which will have its first test next year .

3. Three Brahmos regiments are operational with the Indian Army with another two on the way. I knew the fourth Brahmos regiment with Brahmos block 3 steep dive capability and the ability to hit targets on the reverse slope is already operational . Ten ships of the Indian Navy are already having the Brahmos as their prime strike weapon. Two ships are now being fitted out with Brahmos uvls and missiles. I reckon these are the Visakhapatnam and INS Delhi which is undergoing a MLU . All principal warships aree now getting Brahmos.

4. Orders amounting to a massive Rs 36000 crore has already been placed wrt Brahmos . Further orders are on the way.
 

Arihant Roy

Senior Member
Joined
Jan 25, 2018
Messages
1,012
Likes
6,289
Country flag
Four regiments of Brahmos are currently operational with Indian army .

1 861st regiment with 40th Artillery division .
2 881at regiment with 41st Artillery division.
3. 1889th regiment with 42 nd artillery division.
4. Fourth regiment is under Eastern command .

The artillery divisions are part of the strike corps. So Brahmos usage comes under the authority of strike Corps commanders .

The fifth regiment will go the 17 Mountain strike corps headquarted at Panagarh with 59 mountain division and 72nd Mountain division.
 

kurup

Regular Member
Joined
Sep 22, 2012
Messages
480
Likes
919
Country flag
Is it possible to convert the existing Bmos to ER version ?

With the implementation of waypoints , the only thing misding in Bmos is TERCOM , which may be impossible because of the high speed of the missile .
 

Global Defence

New threads

Articles

Top