Long range Agni missile & test launch :Part-1

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bala
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Post by bala »

The NPA's are joined at the hip with GOTUS. They're shown separate only for plausible deniability. The same NPAs said/did nothing abt the cheen-pak nexus violating NPT and MTCR..
This reminds me of the movie Sting (Robert Redford and Paul Newman) and the con job of ticker by ticker play. The cheen-pak are the setup and the US plays India after the British looted India.
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Post by Arun_S »

Some other reports that I missed in last 4 weeks.
After

Agni, India plans 5,000-km missile
15 Apr 2007, 0023 hrs IST,Rajat Pandit,TNN

NEW DELHI: India is now on the "glide path" towards developing an intercontinental ballistic missile (ICBM), with a strike range in excess of 5,000 km, after the successful test of the 3,500-km Agni-III on Thursday.

If there is a political directive, the Defence Research and Development Organisation (DRDO), often criticised for time and cost overruns in its projects, now feels confident enough to assert it can come up with a three-stage solid-fuelled ICBM in the next two to three years.

DRDO is yet to reveal whether the proposed ICBM will be called Agni-IV or Surya-I. But yes, with "a canistered version" of Agni-III also on the cards, even a submarine-launched ballistic missile (SLBM), the most secure and effective system for a nuclear strike, is now well within the realm of possibility. DRDO chief M Natarajan on Friday said it may be "possible to squeeze in a third-stage" in a 16.7-metre tall missile like the Agni-III, by miniaturising some of its systems, to extend its range to 5,000 km with a 1.5-tonne payload.

"We will certainly work towards this goal. We can draw on the advantage of the new solid rocket motors designed for the two stages of Agni-III," he added. But the DRDO chief then added a caveat.

"It is our job to build technical capabilities. Where the warhead should go, to what range, is a political decision
or diktat," he said.

Agni-III mission director Avinash Chander added, "Agni-III, the first Indian missile to cross the equator, can be used as a stepping stone for building other systems like a canistered version or a missile with a much longer range."

ICBMs, which borrow heavily from space launch vehicles, have till now largely remained the preserve of the five permanent members of the UN Security Council, with US and Russia leading the pack since the 1960s.

Lately, China too has made huge strides in the ICBM arena, developing new-generation solid-fuelled road-mobile ICBMs like DF-31 (7,250-km-plus) and DF-31A (11,270-km).

On its part, the Agni-III intermediate range ballistic missile is a two-stage solid-fuelled system, with a 1.5-tonne payload, which includes the warhead, an inertial navigation system and an on-board computer to guide the missile. An entirely new system, it weighs a massive 48 tonnes, unlike the much lighter 700-km Agni-I (12-tonne) and 2000-km-plus Agni-II (17-tonne) now being inducted into the armed forces.

Confirming TOI's report on Thursday, Natarajan said, "We will carry out 2-3 more tests of Agni-III. It will take 2-3 years to declare it ready for production and handing over to armed forces."

Chander, in turn, said the production of Agni-III will not be a problem since most of the technologies for the missile were developed in-house, and the components were mainly produced by the private sector. "As many as 258 private industrial units and 20 labs have participated in this programme," he said.

rajat.pandit@timesgroup.com
And here in Dec-2007 Avinash Chandra is talking of requiring 3 more tests, but today GoI fearing Indian public outrage is duping and deluding itself by prematurely announcing development phase of Agni-3 complete (Remember GW Bushs' "Mission Accomplished" fiasco?) and ready for operational induction. It is thinking Indian population will soon forget about Chinese forward nuclear sub-deployment threat to Indian people.

India plans 6,000-km range Agni-IV missile
13 Dec 2007, 0143 hrs IST,TNN
NEW DELHI: In what could provide India greater strategic depth, the government on Wednesday announced its plan to develop 6,000-km range Agni-IV missile which will be capable of destroying targets deep in China.

The announcement is seen as a move to send out strong signals to countries in the neighbourhood. Any missile with a range of more than 5,000 km stationed in south or central India would be out of the range of most capable missiles in Pakistan's arsenal while it would be able to hit targets in eastern and northern China with cities like Beijing and Shanghai in its ambit.

The 3,500-km Agni-III, which was successfully test-fired in April, will not be able to reach cities like Beijing unless it is deployed in eastern states near the Chinese border.

Top scientist V K Saraswat of the Defence Research and Development Organisation (DRDO) said the Agni-IV project was in the design stage and its trials and development could take a few years.

Saraswat said the DRDO would carry out three more tests of Agni-III over the next year with the second trial of the missile slated by June. The 3,500-km range missile, which has the capacity to carry a nuclear payload of upto 1.5 tonnes, is likely to be inducted into the forces by 2009 after at least three successful tests.


The DRDO scientist said India would have a complete ballistic missile defence (BMD) system in three years — ready and deployed. The system will have interceptor missiles that can hit targets 50-km above the atmosphere and supersonic interceptors that can eliminate endo-atmospheric targets 15-km within the atmosphere.

Believed to be superior to America's Patriot, the BMD system has been in development for the last eight years. As part of the programme, the Prithvi air defence missile was tested in November 2006 while advanced air defence interceptor was tested this month.

The development of 6,000-km Agni-IV also indicates that the country has shelved plans to develop Inter-Continental Ballistic Missiles which would have hit far away targets.

There had been speculations of India developing an ICBM named Surya with a range of more than 10,000-km. However, in light of the ongoing negotiations on Indo-US nuclear deal, it is quite possible that India may not like to annoy US.
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Post by Raj Malhotra »

IIRC SS-20 of era 1975, weighed 37 tons with throw weight of 1.5 tons and range of around 5000km.

My guess with agni-3 weighing 50 tons is that it has throw weight of 3 tons and range of 5000km with "fractional payload" to meet all exigencies
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Post by SaiK »

A miniaturised submarine-launched version of the Agni-III called Agni-III SL is also being developed and could be test-fired shortly.

Unlike Agni-I and Agni-II, the Agni-III missile has been designed and optimised to carry lighter 200 KT thermo nuclear pay-load weapons.


The third stage booster being installed for the future Agni range of missiles will give them capability of hitting targets at longer distances fairly accurately.
For the first time, the missile scientists flight-tested high performance indigenous Ring Laser Gyro based navigation system in the Agni range of missiles. So far the DRDO has been using Strap-dowm Inertial Navigation Systems.

With the revival of the Indo-Russian GLONASS project, which will be in orbit by 2010, Indian missiles are expected to have more precision.


The missiles re-enters into the atmosphere with a very high velocity and experiences a de-celeration of more than 35 g and a temperature of more than 2500 degree Celsius, but the pay-load is protected by all carbon composite heat sheet.

The missile systems is equipped with sophisticated navigation, guidance and controlled systems along with advanced distributed architecture based on-board computer systems. The missile has an electronic system which are hardened for higher vibration, thermal and acoustic effects.


clik
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Post by Rahul Shukla »

Bakistan has just fired the Hatf IV (Ra'ad) cruise missile as expected. I am very sorry if all of you kafirs have nightmares tonight.
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Post by Shankar »

he SS-20 was an intermediate-range, road mobile, solid propellant ballistic missile. It was built as a replacement for the fixed surface-based SS-4 and SS-5 intermediate range systems. It is believed that the SS-20 was simply the first two stages of the three-stage road mobile SS-16 ICBM. The range was insufficient to directly threaten the US, but all strategic targets within Europe could be targeted.



The SS-20 was launched from a Transporter-Erector-Launcher (TEL) vehicle derived from previous TEL vehicles, ultimately tracing its descent to the ‘Scud B’ system. The missile was fired from a launch canister mounted on the six-axle wheeled truck. The TEL vehicles were typically based in concrete shelters with sliding roofs designed to allow for launch from inside the shelter, though the SS-20 could also be launched from a geodetically prepared field site. The mobility of the system significantly increased its survivability in the advent of a conventional or nuclear conflict. This allowed the Soviet Union to maintain deterrence against a pre-emptive strike while having the ability to engage European targets with the SS-20 and focus the ICBM force against the United States.



An early version of the SS-20 was equipped with a 50 kT warhead and reached a test launch range of over 7,400 km (4,598 miles), but this version did not enter service. An upgraded version entered service in 1982 with better range and accuracy, but this was probably not put into service.



The Mod 1 design of the SS-20 delivered a 1,740 kg payload of 3 150 kT yield MIRVs up to a maximum range of 4,700 km (2,920 miles). The Mod 2 was essentially identical except for an improved range to 5,000 km (3,107 miles). Both versions were constrained by a minimum range of 600 km (373 miles) and an accuracy of 550 m CEP. The total launch weight was 37,100 kg. The missile used a two-stage solid propellant engine and had a total length of 16.49 m with a width of 1.79 m.



The SS-20 entered the development stage in 1966, with flight tests beginning in 1974. It entered service in the Soviet Union in 1976. In 1987, 495 were deployed with another 245 non-deployed in 29 separate locations. The number was reduced to 405 by 1987 and by May 1991 all SS-20 missiles were destroyed in accordance with the Intermediate-Range Nuclear Forces (INF) Treaty. A number of SS-20 launch bases that were not dismantled were converted to accommodate the mobile version of the SS-25.(1)
assuming thr Russian general who was once in charge of some of soviet strategic missiles knows waht he is saying

Agni 3 has an undoctored normal range of 7500 kms
a payload of 1500 kgs
and capable of MIRV ed with 3x 150/200 kt thermo nuclear warheads

makes sense to me .He never said agni 3 is a copy -all he said is its possible true capability is similar to SS-20
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Post by Shankar »

W[quote]ith the successful test-fire, Agni-III is the missile with the longest reach in South Asia and more powerful than any missile in Pakistan's arsenal. However, China has missiles with a longer reach.

After three postponements, Agni III was first test fired on July 9, 2006, but the missile failed to meet its mission objectives due to cascaded failure of booster flex nozzle controller.

Initially, Indian scientists had planned only three tests, before its induction in 2008. However, DRDO sources said with the failure of maiden test flight, more tests would now be required to prove its robustness.

Though DRDO officials are tightlipped, well informed sources said that Agni III costs about 1/6th of similar missiles developed by western countries.

Amongst the range of Agni missiles, Agni III is the country's first solid fuel missile that is compact and small enough for easy mobility and can be easily packaged for deployment on variety of surface and sub-surface platforms.

The missile, DRDO scentists say will support a wide range of warhead configurations with total playload mass ranging from 600 kg to 1,800 kg.[/quote]
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Post by Arun_S »

Arun_S wrote:
lakshmic wrote: From the pictures, it seems to be 2 stage (onleee) with the payload adapter and no MIRV. The vented interstage is very much present. Looks identical to A-III (2). Unless there is some deep SDRE earth-e-shatter going on with the pictures.
Indeed what was launched was a 2 stage missile. Few observations:
  • 1.) For the first time they released pics that shows the fine structure in the nose cones (all the patch antenna etc) that I had carefully masked out in the A3-D1 high res pic. Of course one can also see patch antenna on other stages.

    2) The Chankian SRDE this time around left tell tale and (in fact made prominent) dashed lines on all the stages that mark the ends of solid fuel pressure vessel or mounting/separation point (for the SC explosive bolts). To give clear indication of how much garam masala did I fill in the volume. Once can then factor in length of the exhaust funnel and the available space left in the cylinder.

    3.) No pic released this time of the puffing upper stage at the moment of lift off (unlike pics released at the time of D2).

    4.) The TEL support point also gives fair bit of information. The support structure indicate the weight is born at the end of the stage (cantilever) and not at mid section of pressure vessel. Again reconfirms where the pressure vessel ends . (Of course the booster is supported differently due to other considerations)

    5.) If one sees more carefully you can see where the location of 3rd stage motor will be. 8)

    6.) I need to do more image analysis (in free time) but I see that the upper stage pressure vessel is a bit longer, compared to A3-D2.
Now some crystal gazing/analysis:
  • A.) They upper stage motor this time is composite case and not maraging steel used in A3-D2.

    B.) The 1.5tonne payload, 350Km apogee altitude, 800 sec flight time are incompatible for any reasonable missile confign estimate for a normal trajectory. If only the missile did a mid-flight course change will the 350Km altitude and 800 second time be possible. That is akin to test of new Russian missiles.

    C.) If one looks carefully at the black nose cone (zoom-in will help), one can see 4 parts (3 separation lines) with the outline of a small RV on the tip.
Upon closer inspection I found that the second stage exhaust nozzle extends all the way upto the interstage. Zoom in to high magnification clearly shows that.
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Post by sauravjha »

the Agni -3 TD is generations ahead. The SS-20 had progressively slimmer stages and even it's first stage wasn't 2.0 m in diameter. Not to mention avionics, payload adapter , composite stages, etc.

The russki general is probably on a nostalgia trip and used the SS-20 to only make a point about the range .
Of course, if NPA's seize upon this statement to denigrate Indian capabilities, who cares?
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Post by Singha »

could it be a deliberately flatter non ballistic trajectory to delay being
visible to enemy ABM radars ? at the cost of some range ofcourse.
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Post by ranganathan »

sauravjha wrote:the Agni -3 TD is generations ahead. The SS-20 had progressively slimmer stages and even it's first stage wasn't 2.0 m in diameter. Not to mention avionics, payload adapter , composite stages, etc.

The russki general is probably on a nostalgia trip and used the SS-20 to only make a point about the range .
Of course, if NPA's seize upon this statement to denigrate Indian capabilities, who cares?
Denigrate? Injuns themselves are only claiming 3000 km. The russian general is doing us a favor.
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Post by geeth »

>>>could it be a deliberately flatter non ballistic trajectory to delay being
visible to enemy ABM radars ? at the cost of some range ofcourse.

It may not be a flatter trajectory, if it had gone upto the quoted altitude of 350 KM. However, my feeling is that the range quoted is the MINIMUM range with the MAXIMUM payload. The MAXIMUM range with MINIMUM Payload could be more than 8000 KM
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Post by Arun_S »

lakshmic wrote:
Arun_S wrote:Also it need to be re-emphasized that the previous A3-D2 was 48 tonne liftoff mass, and now TS.Subramanium has confirmed the A3-D3 mass was 50 tonne. I have an inkling of what is going on. :wink:
No third stage, same fuel mass, if at all the casing should have lost weight if it is composite instead of maraging steel. Where did this additional 2t come from ? A steel model of 4 flower petals inside the cone to check out flight parameters ? or 1.4t fuel 2t weight HAM/PBV ?
All the above, recall that A3-D2 was also extra heavy at 48 tonne and it had mass that was unaccounted for just in the mass of the motors alone. That 2 additional tonne is from additional weight that was not put in in A3-D2 apart from the fact that this Second stage motor has bit more masala.

Avinaish Chandra's precise statement of 800 seconds flight time and 350 Km altitude is a clear message by to people in the trade who understand the subject matter that the missile did not fly a simple ballistic (depressed or elevated) trajectory, because that leads to no ballistic trajectory solution (physically impossible). It certainly did a fair bit of Shiv Tandav Nrytya celestially. And after all that Shiv Nrytya if the navigation system delivered <10% bulls eye centering, that is indeed a fearsom "Shiv Tandav" missile.

Comparison with recent Russian missile dance is not entirely unreasonable. :wink:

Jai Jai Natraj.
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Post by vivek_ahuja »

geeth wrote:It may not be a flatter trajectory, if it had gone upto the quoted altitude of 350 KM.
Actually, it is a very depressed trajectory. Missiles in the class of the A-III can rise to an apogee of beyond 1000Km when going for the MAX-RANGE condition. At the moment I am not even sure what the nature of the trajectory is! Arun Saar has suggested that there was some in flight course correction involved. Perhaps he can elaborate how that might have taken place...
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Post by SSridhar »

Agni-3 is not against anybody
India's long-range nuclear capable Agni-III missile, which was successfully tested on Wednesday, is not aimed at any particular country but can hit targets deep inside China or any West Asian country, according to Group Captain RK Das, spokesperson of the Indian Army's Eastern Command. :lol: {Excellent}

"The Agni-III is not country specific but was test-fired to strengthen our military power. With the successful launch of the missile, India has joined the league of global superpowers like China, France, Russia, US and UK who already have this type of weapons in their possession," Das said here Wednesday evening.

He said: "With this missile, India can even strike Shanghai. {But, most definitely, it is not against anybody} Agni-III was developed indigenously by scientists in India. The research and development activity of the missile had been on for the past eight years."

"We can't let ourselves be unprotected. We have built a capability to retaliate if we are threatened. This missile would help India form a credible defence from China. With this launch, China will think twice before attacking us," Das said.
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Post by Arun_S »

Singha wrote:could it be a deliberately flatter non ballistic trajectory to delay being
visible to enemy ABM radars ? at the cost of some range ofcourse.
Saar, I tries all that. All that flat or loft is impossible to generate 350Km and 800 second. Except when it does Natraj Nrytya.
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Post by sauravjha »

the re-entry velocity was 4km/sec which I think is up there with best.


the boost phase altitude of most ICBMs can be up to 400 km , so this isn't a particularly depressed trajectory launch.


if I am not mistaken , depressed trajectory launch may not only lead to IRBM ranges but IRBM re-entry velocity as well. So my take is, that the physics defying yindoo ICBM continues to be enigmatic.
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Post by vivek_ahuja »

Arun_S wrote:All the above, recall that A3-D2 was also extra heavy at 48 tonne and it had mass that was unaccounted for just in the mass of the motors alone. That 2 additional tonne is from additional weight that was not put in in A3-D2 apart from the fact that this Second stage motor has bit more masala.
Whoa! Arun Saar, can you elaborate what that was about?
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Post by rakall »

Arun_S wrote:
Singha wrote:could it be a deliberately flatter non ballistic trajectory to delay being
visible to enemy ABM radars ? at the cost of some range ofcourse.
Saar, I tries all that. All that flat or loft is impossible to generate 350Km and 800 second. Except when it does Natraj Nrytya.
Arun -- I tried with a 36deg angle and got values closer to 350km & 800second. Got 380km, 870sec and 300km.. A little bit flatter might match with 350km & 800sec.

But if there was some eggstra manuevring at 350km-- always better.
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Post by vivek_ahuja »

Rakall,

I have been trying to do what you have posted here and before (albeit not on Rocksim but still...) and at the risk of sounding stupid, I am guessing that when you say you have launched a missile at 36 degrees, you mean the injection point at second stage burnout, right?

The thing is, I have been trying that all day and there is no way of getting less than 12 to 13 minutes flight time even at the lowest of injection angles.

In fact, the second stage burout for the A-III itself is at 348 Km roughly per my calculations.

Unless you are launching the missile at 36 degrees at ground point or something... :shock:
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Post by Arun_S »

vivek_ahuja wrote:
geeth wrote:It may not be a flatter trajectory, if it had gone upto the quoted altitude of 350 KM.
Actually, it is a very depressed trajectory. Missiles in the class of the A-III can rise to an apogee of beyond 1000Km when going for the MAX-RANGE condition. At the moment I am not even sure what the nature of the trajectory is! Arun Saar has suggested that there was some in flight course correction involved. Perhaps he can elaborate how that might have taken place...
Many ways: One or more of the following:
1. Mid course dog-leg azimuth change (is an effective ABM maneuver to throw offtrack early warning sensor network)
2. Mid course elevation variance and recovery from elliptic path
3. Energy wasting spiral climb.

However bouncing / skipping atmosphere during re-entry is unlikely at such short 3000 km range.
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Post by vivek_ahuja »

Arun_S wrote:
vivek_ahuja wrote: Actually, it is a very depressed trajectory. Missiles in the class of the A-III can rise to an apogee of beyond 1000Km when going for the MAX-RANGE condition. At the moment I am not even sure what the nature of the trajectory is! Arun Saar has suggested that there was some in flight course correction involved. Perhaps he can elaborate how that might have taken place...
Many ways: One or more of the following:
1. Mid course dog-leg azimuth change (is an effective ABM maneuver to throw offtrack early warning sensor network)
2. Mid course elevation variance and recovery from elliptic path
3. Energy wasting spiral climb.

However bouncing / skipping atmosphere during re-entry is unlikely at such short 3000 km range.
Nice. And this pretty well breaks up the projectile phase of the flight so that all those calculations are expectedly rendered useless.

So this means that the flight was far more complex than what would be believed at first glance. That's nice too.
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Post by rakall »

vivek_ahuja wrote:Rakall,

I have been trying to do what you have posted here and before (albeit not on Rocksim but still...) and at the risk of sounding stupid, I am guessing that when you say you have launched a missile at 36 degrees, you mean the injection point at second stage burnout, right?

The thing is, I have been trying that all day and there is no way of getting less than 12 to 13 minutes flight time even at the lowest of injection angles.

In fact, the second stage burout for the A-III itself is at 348 Km roughly per my calculations.

Unless you are launching the missile at 36 degrees at ground point or something... :shock:

Have you tried with a Stage1 thrust angle of 36deg? That is what I did..

obviously at the ground level it lifts-off vertically, but just a few km above the ground it should start to tilt in the general direction of the target.. but, i guess, you can input the thrust angle at stage 1 itself
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Post by Arun_S »

rakall wrote:
Arun_S wrote:Saar, I tries all that. All that flat or loft is impossible to generate 350Km and 800 second. Except when it does Natraj Nrytya.
Arun -- I tried with a 36deg angle and got values closer to 350km & 800second. Got 380km, 870sec and 300km.. A little bit flatter might match with 350km & 800sec.

But if there was some eggstra manuevring at 350km-- always better.
What is the stage configuration you used?
I use a variation of

Code: Select all

Launch Direction = 150 degrees-North,  Launch Latitude = 22.00 degrees

Segment-Name ISP(Vac) ISP(SL) Stage-Mass  Fuel-Fract  Burn-Time Thrust-Direction  Diameter   
Stage1           269.0   237.0,   34,000.0     0.920     090.0 Sec   50.0 Degree  2.00 Meter 
Stage2           294.0   190.0,   12,000.0     0.900     110.0 Sec   36.0 Degree  2.00 Meter  
PayloadAdaptor   000.0   000.0,   00,150.0     0.700     001.0 Sec   00.0 Degree  1.00 Meter 
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Post by rakall »

Arun_S wrote:What is the stage configuration you used?
I use a variation of

Code: Select all

Launch Direction = 150 degrees-North,  Launch Latitude = 22.00 degrees

Segment-Name ISP(Vac) ISP(SL) Stage-Mass  Fuel-Fract  Burn-Time Thrust-Direction  Diameter   
Stage1           269.0   237.0,   34,000.0     0.920     090.0 Sec   50.0 Degree  2.00 Meter 
Stage2           294.0   190.0,   12,000.0     0.900     110.0 Sec   36.0 Degree  2.00 Meter  
PayloadAdaptor   000.0   000.0,   00,150.0     0.700     001.0 Sec   00.0 Degree  1.00 Meter 

I went very conservative..

I used the Isp values for A2-std 259/232 & 276/220 for the two stages respectively...
34000, 11000 for stage weights.. mass fraction 0.875 for both stages.. Burntime 75 & 100 as per your inputs on BR-Missiles page for A3-TD config
I allowed the payload to be 3000kg = 1500kg for payload + 1500 deadweight to account for PBV (future)

1st stage thrust angle 36deg, 2nd stage thrust angle 31deg for depressed trajectory gave me 380km, 3300km, 870sec.

the same for 51deg, 41deg angles gave me 1000km, 5000km, 1455sec..

I will try to repeat the same and report again.. let me check anyway..
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Post by Arun_S »

rakall : I can't get below 900 second even if I tyy to put a heavy payload and hit 350 km apogee. That 100 second is a big thing, particularly if it is achieved by saddling 3500kg payload.
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Post by Shankar »

since we are discussing range -trajectory flight time of an ICBM potential of agni 3 -found some interesting comments on the net after a recent Topol M 27 missile launch specifically on an a abm avoidance flight path like Arun's Shiv Tandava
Comments

Reports on this test by the major media (Xinhua, Interfax, AP) have been quite contradictory, both in terms of the missile tested (Topol SS25 vs Topol M SS27), and the place where the missile was launched from (variously, Plestsk or Kapustan Yar). Can you please confirm details?
[DB] [November 2, 2005] [#]

Yes, the reports are quite contradictory. There seems to be some confusion about which of the Topols was tested. I relied on a report by Ivan Safronov in Kommersant - he is usually a very reliable source.
[Pavel Podvig] [November 2, 2005] [#]

I'm a bit surprised that an ICBM can fly as short a flight as that, especially if it was launched from Kapustin Yar. But I suppose if you want the option of nuking China as well as the US you need a fair degree of flexibility in missile range characteristics. (Is this all explained in the book?)

Also, assuming the trajectory was neither lofted nor depressed, does this mean the booster was shut down significantly early and the missile flew an IRBM-like trajectory at an IRBM-like speed? Depending on the missile defence penetration technique used, I would think that might make a significant difference in the system's performance.
[Bill Robinson] [November 2, 2005] [#]

I don't think it's that unusual to launch a missile on a lofted or depressed trajectory. The Soviet Union used Sary-Shagan to test its missile defenses. I would guess it had experience with launching all kind of missile on all kinds of trajectories.
[Pavel Podvig] [November 2, 2005] [#]

Hmm. OK, thanks.

I suppose a lofted trajectory, in particular, wouldn't present any real problems. Slight lofting may be the most likely means of adjusting the missile's range to whatever it needs to be either for testing or actual use. Depressed trajectories might present more problems, due to higher aerodynamic loadings on the missile during boost and the longer and shallower re-entry. I read somewhere that Soviet SLBMs (at least) were never tested on a depressed trajectory. Maybe that was wrong or is now out of date, or can be simply explained by their shorter ranges being more compatible with the distance to the test areas.

Significant depressing or lofting, as we might expect for ICBMs on a short test flight, would make for much shallower or much steeper re-entries, respectively, that would, it seems to me, also change the performance of the re-entry vehicle and penetration aids during missile-defence tests.

Still, as you say, the Soviet Union chose to do its missile-defence testing at Sary-Shagan. They must have calculated that whatever the performance differences inherent in that location were, they were not large enough to prevent sufficiently realistic testing. (Or maybe, like the MDA, they were never all that concerned about realistic testing.)

Cheers.
[Bill Robinson] [November 3, 2005] [#]

The wording of the press release is similar to the language used to describe the gliding payload tested aboard the RS-18 in 2004. Is it possible they've retrofitted the vehicle for flight aboard a smaller ICBM, or designed a smaller version of the IGLA? If the payload was a glide vehicle (instead of a typical RV) then any range under the missile's normal range would be unsurprising -- a glide vehicle with sufficient heat shielding could perform a pitch-down maneuver at almost any point in its flight.
[Anonymous] [November 8, 2005] [#]

There has been so much confusion about that "glide vehicle" and about this test that I would not trust the reports that link them together. We'll just have to wait for more information. My guess is that it was a test of regular (or advanced) decoys and penetration aids.
[Pavel Podvig] [November 8, 2005] [#]

Bill Gertz weighs in:
http://www.washingtontimes.com/national ... -2217r.htm
[Bill Robinson] [November 22, 2005] [#]

Yes, but his evidence is quite thin. He basically recycles Russian press reports, which are not quite consistent to say the least.
[Pavel Podvig] [November 22, 2005] [#]

Something related to the maneuverable warhead known as Igla? There are some articles from N. Sokov talking about this warhead. It looks as a very impressive gadget to defeat NMD
[Rodolfo] [December 14, 2005] [#]

I would be very cautious about trusting reports about "Igla" or whatever "maneuverable warhead" is there. A lot of this talk is just speculation based on poor reporting.
[Pavel Podvig] [December 15, 2005] [#]
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Whatever it is -this test validated loads of data to be used later - agni is not a missile but a weapon system and avoiding interception is surely part of the system

the flight time and range just does not match at 15 minutes flight time range will have to be much much larger .How the DRDO managed to do it is million dollar question for the world and the trillion dollar question is -why they did it

Since the russian general opened up the discussion on true capability by comparing with ss-20 just was checking on Topol M test

-Shankarosky
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Post by vivek_ahuja »

rakall wrote:Have you tried with a Stage1 thrust angle of 36deg? That is what I did..

obviously at the ground level it lifts-off vertically, but just a few km above the ground it should start to tilt in the general direction of the target.. but, i guess, you can input the thrust angle at stage 1 itself
Um, the thing is you have to keep an eye out for the weight of the missile and its attitude at all those points else it is liable to tilt over in flight. This puts limits on the angles. I am not sure on how Rocksim calculates this, but my model had a tracker designed to check this factor against vehicle attitude. And sure enough, as I put 36 degrees for first stage angle at burnout, the rocket tilts over and is lost during the second stage flight.

Attempting this manuevere in the second stage might work, but after that the only way to bring the missile down in the stipulated time would involve the flight changes that Arun has already spoken about.
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Post by Arun_S »

My ROCKSIM developer gave the gayan on the matter. Fortunately for rocketry exploration ROCKSIM allows unconstrained Angle of Attack. So if one can build a propulsion and control system to realize a particular thust vector in low altitude, the simulation will be valid (except for a small drag coefficient error due to aerodynamic lifting body in this case.

Irrespetive of that detail ROCKSIM allows an aggressive flight modal for the master vehicle designers. So its simulation of shallow flight is valid.

For the perfectionist, one can simply model the booster into 2 virtual stages; the first stage with a near vertical inclination thus using gravity assisted attitude rotation (using 1.0 Mass Fraction for that part of the virtual motor partition) and the second virtual stage with a different inclination (but with the full stage dead weight).

Rakall: for a composite case Booster and second stage a Mass Fraction <9.0 is not real.
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Post by rakall »

Arun_S wrote:rakall : I can't get below 900 second even if I tyy to put a heavy payload and hit 350 km apogee. That 100 second is a big thing, particularly if it is achieved by saddling 3500kg payload.
Yes and very much.. Actually if you remember -- A3-D2 flight time was 15min (if the reporting was accurate).. However - yesterday suddenly the 350km max alt & 800sec flight time sounded too low for a 48T behemoth.. even if the kafir yindoos are very inefficient..

I did not save yesterday's config.. but tried to repeat it best.. I am just posting(below) screenshots of my repeat effort.. Note - at first I overlooked interstage.. so i allowed the second stage inert mass to fly with the payload.. so at burnout i am actually flying with 2900kg instead of payload weight of 1500kg.. In this repeat run i got 893secs.. but if the payload is increased to 1750 -- mass at burnout 3150, then i think i will get yesterday's value of 872secs..

Anyway the fact of the matter is -- even for 1500kg payload, even a 2stage Agni3 has a lot more legs/flight in it than the stated 3500km..
Once they make it 3stage for a 1000kg payload -- WOW range..


Image


On a side note: One should kick Vishal Thapar's arse mighty hard -- for his piece on CNN-IBN yesterday
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Post by rakall »

Arun_S wrote:
Rakall: for a composite case Booster and second stage a Mass Fraction <9.0 is not real

.
Yes Arun.. I have read your missile's page more than a dozen times and every single revision of it.. Followed every single detail from the "handing over of 1.2m dia MS steel casing" to "2m dia composite case".

But you know some very pessimistic yindoos consider their motherland's scientists to be very inefficient.. so keeping that in mind I did a "worst case" scenario simulation -- very very conservative.. (Cmon how can we achieve a massfraction of 0.9... after all this is India only).
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Post by vivek_ahuja »

Arun_S wrote:My ROCKSIM developer gave the gayan on the matter. Fortunately for rocketry exploration ROCKSIM allows unconstrained Angle of Attack. So if one can build a propulsion and control system to realize a particular thust vector in low altitude, the simulation will be valid (except for a small drag coefficient error due to aerodynamic lifting body in this case.

Irrespetive of that detail ROCKSIM allows an aggressive flight modal for the master vehicle designers. So its simulation of shallow flight is valid.

For the perfectionist, one can simply model the booster into 2 virtual stages; the first stage with a near vertical inclination thus using gravity assisted attitude rotation (using 1.0 Mass Fraction for that part of the virtual motor partition) and the second virtual stage with a different inclination (but with the full stage dead weight).
nice.

BTW, does that mean that ROCKSIM allows these kind of shallow flight simulations with the idea that if it were to be done in reality, this is what the flight would look like? In other words, does it allow you to simply switch the attitude tracker off and on during various design processes and see what the flight profile looks like?

I had to do that on my model. The only way I could see the flight profile was when I had disabled the attitude control. I was able to check what Rakall was saying. I am getting the apogee in the required range, and so the flight time, but not the range by a large margin.

I may be missing something, but AOA adjustment during lift-off still does not get the right numbers!

-Vivek
Last edited by vivek_ahuja on 08 May 2008 14:42, edited 1 time in total.
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Post by Aditya_V »

Army likely to induct Agni-III ballistic missile by next year
http://www.hindu.com/2008/05/08/stories ... 961200.htm
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Post by rakall »

vivek_ahuja wrote: nice.

BTW, does that mean that ROCKSIM allows these kind of shallow flight simulations with the idea that if it were to be done in reality, this is what the flight would look like? In other words, does it allow you to simply switch the attitude tracker off and on during various design processes and see what the flight profile looks like?

I had to do that on my model. The only way I could see the flight profile was when I had disabled the attitude control. Assuming that the missile is able to prevent itself from tilting over, I was able to check what Rakall was saying. I am getting the apogee in the required range, and so the flight time, but not the range by a large margin.

I may be missing something, but AOA adjustment during lift-off still does not get the right numbers!

-Vivek
yes.. Rocksim allows you to fire you Rockets at any desired angle.. that is a minor approximation.. If you see the A3 test fire video -- as it attains a 4-5km altitude the missile begins to tilt in the required direction.. if your missile goes a longway (say till first stage burnout) in a vertical direction, you wouldn't get much range - isnt it?

By firing the missle at 36deg angle in Rocksim -- I got a burnout altitude of 130km for a total burnout time of 175sec for both stages (75+100 respectively).. if the same missile i fire at 51deg (which is near optimum for max range) then i get a burnout altitude of 200km approx

Hope it helps
Last edited by rakall on 08 May 2008 14:32, edited 1 time in total.
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Post by rakall »

Arun,

I have done one more simulation -- same Isp & massfraction as before, but increased mass at burnout to 3167kg..

getting maxalt 830km, flight time 827secs, 2950km range..

Image
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Post by vivek_ahuja »

-self deleted-
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Post by rakall »

vivek_ahuja wrote: Agreed. However, what I am saying is that such a tilt that is required from near vertical to 36 degrees in the first stage is tilting and toppling the missile during the second phase burn. This kind of maneuvering is more realistically accomplished in the second stage burn when the masses are lower. That was why I was interested in the injection point angle, since aggressive AOA maneuvering is better done in that part of the boost phase.
I cannot think of why that should happen.. I think you should have enough momentum from the first stage boosting for it to just tilt/topple. Also the vertical component of acceleration from the second stage thrust should be enough to over come toppling caused by gravity..

Or am I thinking completely on different lines..

vivek_ahuja wrote:
As far the values go, after I had disabled attitude control and ignored the tilt over, I can see how you are getting your values.

But this meant that I had ignored what the inbuilt autopilot of sorts was saying. Can you perhaps see if rocksim can allow some kind of attitude control check since that way I can check if my model is flawed or not.

Thanks
The GUI of the Rocksim does not have any feature for attitude control check.. if there is any in the code -- then only Arun would be able to tell you..

good luck..
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Post by vivek_ahuja »

rakall wrote:I cannot think of why that should happen.. I think you should have enough momentum from the first stage boosting for it to just tilt/topple. Also the vertical component of acceleration from the second stage thrust should be enough to over come toppling caused by gravity..

Or am I thinking completely on different lines..
No, you are right. I had put in some values incorrectly. Just noticed that myself. The missile does not topple after that. The missile has a very peculiar flight profile, especially the velocity profile, but it will fly. That was why I deleted that previous post of mine.

Still, the numbers are close to what is needed but not that close. Need to work on it more, I guess...
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Post by Gerard »

Any speculation why the launch pics show no white puff ring around the nose?
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Post by geeth »

>>>Actually, it is a very depressed trajectory.

IIRC, in the previous launch, they had sent it up for about 100 KM before it splashed south of Andamans..my comment was in that context..Or I had mixed it with the Prithvi launch or something..not sure now.
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