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Bharat-Rakshak- Home PageAGNI - STRATEGIC BALLISTIC MISSILE

Agni-TD, Agni-I, Agni-II, Agni-IIAT, Agni-III, Agni-IV


© Arun Vishwakarma 


Agni is a Sanskrit/Hindi word meaning Fire, given that it is a strategic ballistic missile. The Agni missile family is envisaged to be the mainstay of the Indian missile-based strategic nuclear deterrence. The Agni family will continue to grow its stable, providing a breadth of payload and range capabilities. The Agni-I is a short range ballistic missile (SRBM) with a single stage engine. While the Agni-II is an intermediate range ballistic missile (IRBM) with two solid fuel stages and a Post Boost Vehicle (PBV) integrated into the missile's Re-entry Vehicle (RV). The Agni's manoeuvring RV is made of a carbon-carbon composite material that is light and able to sustain high thermal stresses of re-entry, in a variety of trajectories. The Agni-IIAT is a more advanced version of Agni-II, albeit with more sophisticated and lighter materials, yielding a better range and operating regime. Agni-III is a compact long range missile in development and test phase.

Variants

Chronologically Agni-TD was first developed to quickly prove critical technologies, followed by the Agni-II IRBM, and then a short range version missile called Agni-I. In defense literature/publications this numbering system jumble, leading to the Agni-I name, often confuses readers. Indian reports mention development of the Agni-III and Agni-IV missiles with greater range and payload capability, albeit with great obfuscation to actual configuration and specification. Recently video images of Agni-III were released by DRDO. Based on technical viability and data from news fragments, the Agni family of missiles can be referred to the following likely configurations with what is believed to be the saner nomenclature.

• Agni-TD: Two stage, solid booster and liquid fuelled second stage. IRBM Technology Demonstrator.

• Agni-I (A-1): Single stage, solid fuel, road and rail mobile, short-range ballistic missile (SRBM).

• Agni-II (A-2): Two stage, solid fuel, road and rail mobile, Intermediate Range Ballistic Missile (IRBM).

• Agni-IIAT (A-2AT): Improved A-2 variant using more advanced and lighter material. Two stage, solid fuel, road & rail mobile IRBM.

• Agni-III: Two stage, solid fuel, submarine, road and rail mobile, IRBM/ICBM.

• Agni-IV: Three stage, solid fuel, road and rail mobile, ICBM.

DRDO's  Prithvi-II, Agni-I, Agni-II, Agni-IIAT and Agni-III
[Image
© Arun Vishwakarma] 

  Agni-I Agni-II Agni-IIAT Agni-III Agni-III++
. .
Length (m)

15

20

20

14.5

13.5

..

.

Max Diameter (m)

1

1

1.2

1.8

1.8

.

.

Launch Weight - kg
(Including Payload)

12,000

16,000

27,000

44,000 to 48,000

50,000
(estimated)

.

.

Propellant

Solid
(HTPB/AP/AI)

Solid
(HTPB/AP/AI)

Solid
(HTPB/AP/AI)

Solid
(HTPB/AP/AI)

Solid
(HTPB/AP/AI)

.

.

Number of Stages

1

2.5

2.5

2

3

.

.

Payload - kg 

800 - 1,000

800 - 1,000

300 - 1,000

600 - 1,500[1]

 2,490 (conventional)

600 - 1,500 

2490 -3490 (conventional)

.

.

Warhead

Strategic nuclear (15 KT to 250 KT), conventional[2] HE-unitary, penetration, sub-munitions, incendiary or fuel air explosives.

.

.

Guidance

Strap Down - INS (Inertial Navigation System), optionally augmented by GPS terminal guidance with possible radar scene correlation.

INS (full Inertial platform)[3], optionally augmented by GPS/GLONASS/IRSS, possibly with radar scene correlation.
.

.

Range (Payload)

850 km (1,000 kg)

3,300 km (1,000 kg)

4,450 km (700 kg)

4,000 km (1,500 kg)

5,500 km (1,500 kg)[4]

>12,000 km[4.A]

.

.

CEP Accuracy

120 meters

40 meters

20 meters (estimated)

16 meters[4.B]

20 meter (estimated)

.

.

Launch Platform

8 x 8 Tatra TELAR (Transporter Erector Launcher)

Rail Mobile Launcher

8 x 8 Tatra TELAR

Rail Mobile Launcher

Submarine Launcher

Development

India launched the Integrated Guided Missile Development Program (IGMDP) in 1983 to concurrently develop and produce a wide range of missiles for surface-to-surface and surface-to-air roles. The IGMDP mandated development of the Agni, Prithvi, Trishul, Akash, Nag and Astra missile systems is managed by the DRDO. Bharat Dynamics Limited (BDL) manufactures Agni missiles and has the capacity to manufacture 18 missiles per year. A small number (less than five) of Agni-II missiles were believed to be operational in late 2000, and a production rate of 15 to 20 missiles per year has been suggested.

The Agni missile series consist of following missiles (in chronological order):

Agni variants under development (estimated performance):


INTRODUCTION: AGNI-TD/TTB

India's long-range missile program first started in around 1972 as Project Valiant, a three stage (liquid engine) ICBM missile. The project envisaged the use of three 30 tonne thrust liquid propulsion engines[5], developed in 1974, for the first stage booster and the second stage using one engine. The project was subsequently brought to a close and a more integrated missile development program was launched under the aegis of the IGDMP.

The Agni-TD/TTB (Technology Demonstrator / Technology Test Bed) project objectives were to test and validate:

  1. Re-entry test vehicle to evaluate structure, guidance and control during re-entry into earth's atmosphere at hypersonic velocity. The RV used multi-directionally reinforced carbon-fiber preform (MRCP) technology.

  2. Inertial Navigation System.

  3. Rocket Staging.

Compared to the Prithvi, the Agni is a much larger system with a range of 2,500 km and a payload of 1,000 kg[6].The original Agni-TD/TTB was an amalgam of the Prithvi and the SLV-3 booster. The Agni-TD/TTB was a cheap test vehicle to prove re-entry and guidance technology for use on a more advanced platform[7]. The missile used a solid booster that was improved but similar to S-1 stage. Instead of developing a new solid motor for the second stage, which would have involved significant delays, it used a shortened version of the liquid fuelled Prithvi motor.

 

Test flight of the Agni-TD/TTB

Test flight of the Agni-TD/TTB
[Image
© DRDO]

Old Agni-1 tech Test Bed on launch pad

Agni-TD/TTB on launch pad
[Image
© DRDO]

Agni-TD/TTB on launch pad

Agni-TD/TTB on launch pad
[Image
© DRDO]

The first Agni launch on 22 May 1989 used a shortened Prithvi stage as the second stage. The second Agni test used a second stage with more fuel and longer burn that was ignited before separation thus obviating the need of six-ullage motors used in the earlier launch[8]. The RV used multi-directionally reinforced carbon-fiber preform (MRCP) technology[9]. The last test of the basic 'Agni-TD/TTB' on 19 February 1994 was a major technical breakthrough for India. The system tested, included a manoeuvrable re-entry vehicle for increased accuracy with terminal guidance[10]. This terminal guidance system reportedly consists of a scanning correlation optical system based on a scanning focal plane homing head in the infrared and millimetre wavelengths of the electromagnetic spectrum[11]. Considerable un-informed comments exist regarding the fact that Agni was only tested to a range of 1,450 km. No missile actually needs to be tested to a full range. It is possible to lift or depress the trajectory of the missile to simulate a longer range.

Dr. APJ Abdul Kalam stated that the missile could be fully deployed within two years[12]. Dr. Kalam also asserted that the Agni was ready for serial production while some simultaneous development flights aimed at achieving a much greater performance are undertaken[13]. Dr. Kalam claimed that no further test flights are necessary for the basic Agni system and that it is ready for production. In April 1995, Prime Minister PV Narasimha Rao (correctly) denied allegation[14] that under US and G7 pressure, India temporarily paused the Agni program after completion of the TD phase and after three test flights. In fact during the time, Prime Minister Rao secretly sanctioned the development of an augmented version of the Agni[15]as well as speed up efforts to build more advanced nuclear weapons[16] and set up a nuclear command and control system for the safe custody, deployment, and employment of such weapons, distributed over the country to ensure survivability and safety but totally under civilian control[17]. The Agni-TD program ran its course with the development and proving of crucial technologies for full-fledged, multi-staged, long-range ballistic missiles, including re-entry and navigation avionics. This missile reached engineering status and it is believed that none were released to the military, although during the Kargil imbroglio few units were made ready as nuclear deterrence[18]. This model is not believed to exist anymore, having being superseded by the Agni-II that has been put on line production and operationalized[19].

Description

Generally liquid fuelled missiles are more accurate because the navigation & control system can precisely control the impulse from the engine by controlling or limiting its thrust. Solid fuelled rockets can't turn off thrust on demand and further due to subtle manufacturing variances and actual operating conditions the exact impulse from a solid motor isn't known beforehand. All this makes control & aiming more challenging and the missile accuracy suffers unless mitigated by other means. The solid fuelled Agni's trajectory has a shallow re-entry angle and manoeuvring RV (MRV) use body-lift aerodynamics to correct trajectory error, as well as reduce the thermal stress of re-entry. The Agni's RV has a velocity correction package to correct launch trajectory variances. Some Agni RV versions use a set of solid fuelled thruster cartridges[20] of predetermined impulse, allowing the onboard guidance controller to trim velocity, using discrete combination of impulse quantum along desired spatial orientation. 

Re-Entry Vehicle: Agni RV-Mk.1

The Agni's re-entry vehicle is designed to ensure that the temperature inside the vehicle does not exceed 60° Celsius, a condition necessary to protect the warhead and electronic systems placed inside. During tests, the re-entry vehicle technology was fully demonstrated when the nose-cone withstood temperatures of 3,000° Celsius while the inside temperature was only 30° Celsius. The Agni RV-MRV Mk.1 nose tip is made of a multi-directionally woven, reinforced carbon-carbon fiber composite material[21]. The 0.8 meter diameter and ~4 meter long, re-entry vehicle consists of five sections. Each of these sections is made up of a two-layer composite construction. The inner layer is made up of carbon/epoxy filament mould constructed on a CNC winding machine and is designed to bear structural loads. The outer layer is made up of carbon/phenolic filament wound construction and cured in an autoclave at 7 bar pressure[22]. The outer ablative layer ensures high thermal robustness for shock and temperature extremes.

The RV appears to house an integrated High Altitude Motor (HAM), instead of a separate Post Boost Vehicle and classic purely passive ballistic warhead seen in western missiles, that is liquid fuelled and is used to correct impulse variance of solid fuelled stages and subtle launch trajectory variance. The 1980-vintage RV was reportedly designed to be able to carry a BARC-developed, boosted nuclear weapon of 200 KT yield weighing 1000 kg, also of 1980 vintage design. After making room for new and lighter Indian thermonuclear weapon payload, of 1995 vintage design, the MRV has room for about 200 kg (estimated) liquid fuel in pressurized vessels. Although for velocity correction, approximately 50 to 80 kg is estimated to be sufficient. There are indications that the MRV is intended to enter a gliding trajectory[23] when it enters atmosphere at an altitude of 100 km[24]. This has following implications:

1. The missile's range is extended.
2. Less acute re-entry thermal stress.
3. The manoeuvring makes it difficult for ABM defenses to intercept the missile.

Interestingly in 1987 IGDMP/ASL first envisaged developing a re-entry vehicle "designed for 100-250 Kg payload at speed of 7-8 km/sec"[25], clearly corresponding to a just a light weight fission-weapon & ICBM range[26]. But strategic requirement clearly also required high yield weapons that imposes bigger space and weight envelop. After some serious thinking, reviews and debates, the RV was to be designed for bigger payloads to match BARC's high yield weapon. The RV envelop was driven by weapon size and weight parameters corresponding to 200 Kt yield. In the 1980's BARC came up with boosted fission weapon design for the purpose with 1000Kg mass resulting in the Agni RV-MK.1. As evident from Agni-III RV design this first RV-MK.1 design was designed for the ultimate long range. 

Typical flight profile of Ballistic missile and Reentry vehicle

[Image: © Arun Vishwakarma] 

Dynamic pressure on RV @ Mach-8
[Image
© NAL CFTFDD] 

Propulsion

First Stage: The booster motor is one meter in diameter and ten meters in length. It has approximately 9 tons solid propellant and a mass fraction of 0.865 (estimated). The stage features three segments of propellant grain, with an internal star configuration[27] for increased thrust during the initial boost phase. The motor case is made of a high-strength 15CDV6 steel and is fabricated by conventional rolling and welding techniques. The propellant used in Agni-TD consists of the AP-Al-PBAN composite propellant and later Agni variants use HTPB [hydroxyl-terminated polybutadiene]. The propellant is of star configuration[28] with a loading density of 78%. It is case bonded with a liner system between propellant and insulation. The motor's nozzle is built from 15CDV6 steel; a carbon-phenolic thermal protection system is used for the convergent throat, high-density graphite is used for the throat, and carbon and silica-phenolic lining is used in the fore end and aft end of the divergent[29].

Second Stage: Agni-TD used a reduced Prithvi stage as its second stage. The initial test flight used a shortened version of Prithvi with lesser fuel, later flights used full fuel configuration. The liquid fuelled second stage of Agni-TD required in addition, two types of 'Ullage and Retro Motors' to maintain positive G-forces during stage separation and liquid engine startup. Both the ullage and retro motors are made of HE-15 aluminium alloy and use a double-base propellant. The motors are lined inside with high silica glass-phenolic ablative liners. Defense Research & Development Laboratory (DRDL) has expertise in the design, production, inspection, qualification, static-testing, and flight-testing of propulsion systems[30].

Agni-TD/TTB Configuration

  Agni-TD Stage 1 Agni-TD Stage 2 Re-Entry Vehicle

Gross Mass

Fuel Mass

Empty Mass

Stage Fuel-Mass-Ratio[31]

10,800 kg

8,900 kg

? kg

0.865

7,000 kg

(Various) kg

(Various) kg

0.80

50 kg

.

.

Thrust @ Vacuum
Thrust @ Sea Level
(Burn Time)

51,251 Kgf

46,390 Kgf

(49 seconds)

27,227 Kgf

Not Applicable

(32 seconds)

Not Applicable

.

.

Specific-Impulse

ISP @ Vacuum

ISP @ Sea Level

 

259 seconds

232 seconds

 

Not Applicable

232 seconds

Not Applicable

.

.

Length

Diameter

10.3 meters

1.3 meters[32]

6 meters

0.8 meters

4 meters
0.8 meters

.

.

Chamber Pressure[33]

Expansion Ratio

44.1 bar

6.7:1

38.3 bar

14.2:1

Not Applicable

.

.

Propellant

Chemical

Case Material

Solid

HTBP

Steel

Liquid

IRFNA & Xylidiene + Triethylamine

Aluminium Alloy

-

-
Phenolic Glasses

.

.

Number of Engines

(Number of Segments)

1

(3)

1

(1)

Not Applicable

.

.

Control System

Secondary Injection Thrust Vector Control System (SITVCS) with aerodynamic control surfaces

Gimbaled engines

Aerodynamic control surfaces

.

INTRODUCTION: AGNI-II

Evolving Indian Security Environment

During the 1990s, India's security situation gradually worsened with security challenges from China, blatant Chinese nuclear and missiles proliferation to Pakistan, and mutual proliferation between Pakistan and North Korea. The strategic redline was crossed in 1998 when Pakistan tested the North-Korean supplied nuclear capable Ghauri (North Korean No-Dong) missile, that could threaten India's heartland with proliferated nuclear weapons. The international complicity in allowing nuclear proliferation by proxy into the hands of Pakistan and ability to deliver it over long ranges, obtained by trading in black-market North Korean No-Dong missiles, in return for Pakistani nuclear design and enrichment equipment by the Walmart of nuclear and missile black-market run by Pakistani scientist A.Q. Khan and the Pakistani Military. This and other international security developments forced India to go fully nuclear, resulting in the Pokhran-II (POK-II) nuclear test series and its weaponization by developing the Agni family of ballistic missiles that could deliver a variety of payloads over long ranges.

Quick deployment of the Agni-II was possible, by building on the earlier Agni-TD program that provided proven critical technologies and designs required for long range ballistic missiles. Thus when the decision was made to build the Agni weapon system, some quick optimization and ruggedization was done to the basic '1980 vintage' design, including a solid fuelled second stage. Further the solid fuel chemistry, RV and avionics were brought up to state-of-the-art levels. As the Pokhran-II (PoK-II) nuclear test proved a family of more powerful and lighter nuclear weapons, the 200 kt thermonuclear weapon is far lighter compared to 1000 kg earlier budgeted for the 200 kt boosted nuclear weapon. Thus a high yield weapon configuration now assumes a payload of 500 kg, including weapon and RV. However, in the interest of rapid development the basic design that was earlier developed continued to be used and keeping the future option open, for more optimized missile design and lighter payload. The Agni-II missile will be used by 555th Missile Group of the Indian Army.

Description

The Agni-II was first tested on 11 April 1999 at 9:47 a.m. IST (Indian Standard Time), from a converted rail carriage, with a carriage roof that slides open to allow the missile to be raised to the vertical for launch by two large hydraulic pistons. The launch process is controlled from a separate railcar. The missile was launched from the IC-4 pad at Wheeler Island, Balasore. Splash down was 2,000 - 2,100 km. down range in the Bay of Bengal, on a trajectory designed to simulate a range of 2,800 - 3,000 km. The Agni-II missile can also be launched from a road TEL vehicle, as demonstrated in the second test flight on 17 January 2001, at 10:01 a.m. IST (Indian Standard Time) to a range of 2,100 km. This missile has a theoretical maximum range of some 3,000 km with a 1000 kg payload (conventional or strategic).

Tested to range of over 2,000 km, the Agni-II has an all-solid propellant system - though a liquid fuelled configuration is also available and an improved guidance system using Global Positioning System (GPS) has been alleged[34]. After the January 17th test, the missile was cleared for production and it is possible that a production capacity (under-utilised at present) exists for 12 Agni-II missiles per year[35]. On the January 17th test, the missile was alleged to have covered a range of over 2100 km with a 700 kg warhead. As this test was described as being in operational configuration[36], it might be assumed that the Agni-II missile will be deployed with a 700 kg warhead. The range differential between the first (11 April 1999) and second (17 January 2001) tests can be explained by the use of a different trajectory and flight profile[37].

.

Agni-II's various flight stages  Image © India Today

Agni-II's flight stages
[Image
© India Today] 

Test flight of the Agni-II Image © DRDO

Test flight of the Agni-II
[Image: DRDO] 

Agni-II on the launch pad  Image © DRDO

Agni-II on the launch pad
[Image: DRDO] 

.

Agni-II being rolled out for the second test  Image © DRDO

Agni-II rolling out for the second test

[Image: DRDO] 

The rail-mobile Agni-II being wheeled out. Image © DRDO

Rail-mobile Agni-II wheeled out

[Image: DRDO]

he road-mobile Agni-II in front of India Gate, New Delhi. Image © DRDO

The road-mobile Agni-II in front of India Gate, New Delhi.

[Image: DRDO] 

.

The Agni-II missile, on a road-mobile launcher, at the 1999, 2000 and 2002 Republic Day Parades      

The Agni-II missile, on a road-mobile launcher, at the 1999, 2000 and 2002 Republic Day Parades Image © DRDO

The Agni-II missile, on a road-mobile launcher, at the 1999, 2000 and 2002 Republic Day Parades Image © DRDO

The Agni-II missile, on a road-mobile launcher, at the 1999, 2000 and 2002 Republic Day Parades.  

[Image: DRDO]

The Agni-II missile, on a road-mobile launcher, at the 1999, 2000 and 2002 Republic Day Parades Image © DRDO

Agni-II at Republic Day Parade

Agni-II at the 2004 & 06 Republic Day Parades 

[Photo: Antônio Milena (ABr)]

Agni-II at Republic Day Parade  

[Image: Source]

The Agni-II is designed to be launched from a rail-mobile launcher[38]; one that can move on a standard broad-gauge rail system. The technology test-beds, however, had been designed as a road-mobile system. There are pluses and minuses to this change. A rail- and/or road-based missile system reduces vulnerability and allows for greater operational flexibility, while critics feel that the cost of these mobile systems could be higher and that they greatly increase the time for moving from one place to another. Considering that except in some parts - for instance, India's north-eastern region - road infrastructure is available wherever rail tracks are available, the decision to become rail-mobile could mean, in strategic terms, that deployment in India's north-eastern region is to be considered a serious possibility. Since Agni-II is road and rail mobile, it lends flexibility and reduces vulnerability to strikes.

The Agni-II will reportedly always be in a ready-to-fire mode and can be launched within 15 minutes as compared to almost half a day of preparation for the Agni-TD. In May 2001, and again in July 2001, the then-incumbent Defence Minister Jaswant Singh informed the Cabinet Committee on Security (CCS) that the Agni-II missile is operational, limited production had begun and induction being planned during 2001-2002. On 14 March 2002, Defence Minister George Fernandes informed Indian Parliament that the Agni-II has entered the production phase and is under induction. Agni-II is made by BDL in Hyderabad, with a production capacity of 18 missiles/year and costs about Rs.35 crore[39] for each missile.

Propulsion

First Stage: The Agni-II's first stage is largely similar to that of Agni-TD's first stage. However the Agni-II booster is believed to employ more energetic fuel similar to that used on the PSLV's (Polar Satellite Launch Vehicle) booster stage - ISP of 269 (vacuum) and 237 (sea-level). It has a propellant mass of ~9 tons and a mass fraction of 0.865 (estimated).

Second Stage: The Agni-II's second stage weighs ~4200 kg and uses solid fuel propellant. Its case is presumably made of the same material, high-strength 15CDV6 steel, as the booster stage for ease of manufacturing. This solid propellant stage has flex nozzles for thrust vectoring, for precise trajectory control. Unlike the Agni-TD, the solid fuel second stage does not require retro motors for proper stage separation. Evidently it uses a vented inter-stage.

Manoeuvring Re-Entry Vehicle: Agni RV-Mk.2[40]

The 1980-vintage RV was reportedly designed to be able to carry a BARC-developed, boosted nuclear weapon of 200 KT yield weighing 1000 kg, also of 1980 vintage design.  After making room for new and lighter Indian thermonuclear weapon payload[41], of 1995 vintage design, the MRV has room for about 200 kg (estimated) liquid fuel in pressurized vessels. Although for velocity correction, approximately 50 to 80 kg is estimated to be sufficient. At least one variant type uses a set of solid fuelled cartridges for velocity trimming.

Dr. Kalam, said that the complete re-entry hypersonic flow was simulated in Computational Fluid Dynamics, on a super-computer. The RV is reported to have an attitude control system. Some versions have additional aerodynamic manoeuvring fins, presumably this is for use with lighter payload that makes the RV ballistic coefficient small, this prevents accuracy degradation, and be also used to make missile defense more difficult[42]. Unconfirmed reports suggest that an improved optical or radar terminal phase correlation system has been developed to provide accuracy of around 40 meters CEP, although later reports have suggested that the accuracy was around 100 to 200 meters CEP. The RV largely inherits the basic shape, design and technology of the earlier Mk.1 RV of the Agni-TD.

Image © DRDO

Light weight payload require different RV design

[© Arun Vishwakarma] 

Temperature profile on RV Mk-II @ Mach-8

[Image © NAL CFTFDD] 

Clear view of Agni-II re-entry vehicle 

 [Image © DRDO] 

Agni is unlike long-range missiles developed by western missiles where the RV is a passive ballistic load, whose accuracy depends on the launching vehicle's exact insertion into the sub-orbital trajectory. A large inaccuracy associated with the first generation RV, involved spinning the RV for greater stability during re-entry. Second generation western missiles were mostly MIRV (Multiple Independently targetable Re-entry Vehicle) and the accuracy was greatly improved by the payload bus with HAM velocity correction package for more accurate sub-orbit insertion. It also allowed individual MIRV payloads to impart different velocities, so that each can be independently targeted to a different target, albeit in nearby vicinity of each other. As before the RV continued to be passive and purely ballistic.

The Agni-RV Mk.2 is more advanced than the western RVs, because it embodies proposition, navigation and control all the way to the target. The RV re-enters at an altitude of 100 km, at a shallow angle, with a gliding trajectory[43].

Key Features of the Agni-RV Mk.2

Analysis © Arun Vishwakarma

Effect of payload and stage configuration on Agni-II range
[Analysis
© Arun Vishwakarma] 

Avionics, Navigation and Control[46]

The Agni family of missiles uses a strap-down INS system for flight control and navigation. Necessary inertial sensors were indigenously developed for the purpose, including laser rate gyros[47]. Agni's Project Director, Avinash Chander, said the effort to operationalise the missile system was complex, as it involved reducing the host of computer's processing information, both inside the missile and ground control systems, to a single control system. To ensure greater reliability of the missile, they reduced the mass of over 600 different sets of communications channels, involving 24 km of cabling, to just 10 pairs requiring one-eighth of the original wiring.

The Agni introduced a new concept by adopting MIL-STD-1553 databus for all on-board communication and control device interconnection --> mainly INS system, Flight Control Computer, actuators and sensors[48]. It is the standard that is adopted in new civilian & military aircraft (circuit routing and device mounting) and all the software in the Agni-II has been designed around this bus. DRDO sources claim that this reduces the number of connections and also makes the missile more rugged. However, some missile analysts feel that a standard databus may not be the best path to follow. It is said that a customized databus is better because in a standard databus, one tends to use off-the-shelf electronic devices whose performance may not be optimal. However most new missiles are moving towards digital buses using commercial off-the-shelf technology and which enables affordable sub-system replacement.

Accuracy[49]

The Agni-II's navigation and aiming uses an advanced ground based beacon system using a TDOA (Time Delay Of Arrival) technique, similar to a GPS system[50], that constantly provides missile flight position and velocity updates and has been proven in test flights[51]. The TDOA system reportedly improved the accuracy by three times[52,53]. India has demonstrated a measure of mastery in navigation sensors and flight control through its space program. The placement accuracy in GTO (involving powered flight of 1000 seconds much of it in sub-G or gravity free environment) is far more complicated and delicate[54] than that of the sub-orbital trajectory of an IRBM. Thus the GSLV-D2 and F01 GTO Apogee accuracy of 1965 PPM[55, 56] and 361 PPM[57,58] respectively compares with Agni-II's 40 meter CEP at IRBM ranges with 13 PPM accuracy.

It is worthwhile to note that INS error differs for a ballistic missile versus an aircraft. Ballistic missile accuracy is only dependent on the INS accuracy up to the point when rocket fuel is expended (100 seconds for Agni-II) and it exits the atmosphere (> 90 km altitude), after that the trajectory is purely ballistic that is predetermined and easily computed. INS in a combat aircraft requires continuous operation of IMU and navigation computer throughout the flight during which the error keeps building as IMU sensors drift. A ballistic missile that can update its position and velocity from auxiliary means, can completely eliminate the built up error from INS and continue flight at a precise predetermined path, if necessary correcting the launch error by using:

1. Small velocity correction thruster package and/or
2. Aerodynamic manoeuvring during re-entry (this requires active RV configuration with integrated INS and control system).

The Agni-II missile reportedly makes use of both the above techniques. The Agni-II exits atmosphere and expends the second stage at an altitude of 120 km and at a distance of about 150 km. This allows the ground based TDOA system to operate well within Indian Territory and at close range (i.e. robustness against Electronic Warfare interference). The missile maintains LOS (line of sight) well beyond apogee. The overall accuracy is the cumulated sum of:

1. Accuracy of determining geographic coordinate of target and launcher.
2. Accuracy of hitting the designated coordinates that is determined by missile's navigation and control system.

Launching the Agni from a surveyed site is one aspect of item 1 above. The sub-meter target coordinates, using national surveillance assets, (aerospace, sensors, etc) would largely address the accuracy of target coordinate designation. A long-range ballistic missile (passive RV) targeting error is typically spread in a highly elliptic pattern. The CEP is thus adversely biased by a wide error spread in a longitudinal axis (due to shallow incidence angle). The Agni's active manoeuvring RV with onboard IMU (INS) and control system can perform terminal manoeuvre to correct errors and make a more accurate top attack profile using greater incidence angle[59] significantly reducing the longitudinal spread and overall CEP.

Image © Arun Vishwakarma

[Image © Arun Vishwakarma]

Terminal Guidance[60]

With the confusion over the maximum range of Agni-II, comes further perplexity whether the missile is actually fitted with any form of terminal guidance system. This is not an easy question to dismiss with a glib negative answer. The RV of the missile is fitted with some rather prominent manoeuvring fins which permits the warhead to perform porpoising manoeuvres to evade and confuse enemy defenses, implying built-in navigation, IMU and control system. The Agni-II is fitted with a basic strap-down inertial navigation system, rather than with a more advanced (but expensive and less robust) gimballed or platform INS. This is by no means a mean feat, and does not itself mean that the missile has poor accuracy[61]. It would mean, however, that the need for some kind of terminal guidance system is necessary - especially true since DRDO claims that the CEP for Agni-II is three times lower than that of the earlier Agni variant with CEP figures as low as 40 metres being mentioned.

DRDO stated, especially after the first Agni-II test, that it had tested a terminal guidance system that dramatically enhanced accuracy. For adjustments to missile trajectory during flight, which allow for higher accuracy, the second stage booster has a flex nozzle that enables change in the thrust vector direction. The flex nozzle technology was validated in the third stage motor of India's Polar Satellite Launch Vehicle (PSLV). Furthermore, it was alleged that the re-entry vehicle employs a terminal guidance radar operating in the C- and S-bands. Finally, re-entry adjustments have been optimized through on board control software that allows re-entry velocity trimming.

There were also early reports that a terminal guidance system based on ISRO technology was to be employed. This terminal guidance system is reported to be comprised of a scanning correlation optical system based on a scanning focal plane homing head in the infrared and millimeter wavelengths of the electromagnetic spectrum. However, it is not known whether this advanced terminal guidance system has been fully developed. Allegations about the employment of GPS assisted terminal guidance were effectively denied by DRDO scientists, as the external control of the GPS network was thought to be a liability.

DRDO's terminal guidance claim is at times belittled by certain quarters - often anti-DRDO naysayers - who speak in terms of the superior Chinese and North Korean guidance systems and their use by Pakistan. Such comments, usually unsupported by any meaningful evidence cannot be given weight on merit, but it does put renewed emphasis on the need for DRDO to be more forthcoming about the guidance system of the Agni-II. DRDO has nothing to lose and everything to gain by explaining a bit more about the guidance technologies used for Agni-II. At stake is the credibility of the DRDO scientists who have made statements to this effect at earlier dates.

Range[62]

The first point of confusion regarding Agni-II, is what is the missile's maximum range? Below, analysis using public domain data and ballistic calculations, show that the range is greatly influenced by use or non-use of thrusters on the RV (required for velocity trimming) for propulsion as a HAM (High Altitude Motor). There seems to be room in the RV for about ~200 kg fuel (solid or liquid) after allowing for a long but lightweight TN weapon[63]. This RV integrated HAM is referred to as the half stage after the two solid fuelled stages. This stage provides a disproportional increase in range for a lighter RV payload. Thus development of lightweight nuclear weapons is paramount to the missile's range.

When the Agni-II was first launched, then Defence Minster George Fernandes indicated that the maximum range of the Agni-II was 3000 km. Since then, ranges from 2000 km to 2500 km have been bandied about while Dr. Kalam, at Aero India '98, stated that Agni-II had a maximum range of 3,700 km! The range of 2000 km can be excluded, as the system has been tested to greater range in both 1999 and 2001. Given the test to 2300 km in 1999 and 2100 km in 2001, with an apparently lighter payload, would indicate that a variation in trajectory was used and it may be possible to extrapolate some more accurate estimates of Agni-II's maximum range.

It would appear that Agni-II has a theoretical ability to hit a target 3000 km away with a 1000 kg overall payload – (a 250 kg RV's deadweight and a 750 kg warhead). It is suggested that a 200 kiloton 'boosted fission' warhead was earlier developed for the Agni system when it was on the drawing board in the late 80s, however after the Pokhran-II series of nuclear test in May 1998, the 200 KT boosted fission design has clearly given way to a 200 - 300 KT two stage thermonuclear design that is expected to be much lighter. From the tables below, one can see that a number of permutations and combinations are available to DRDO based on the existing Agni-II design and Indian propulsion technology. Range changes can be made by either varying the payload or by altering the engine configuration[64].

Image & Analysis © Arun Vishwakarma

Agni-I and II Range-Payload Configuration Analysis[65]
[Image & Analysis © Arun Vishwakarma] 

Given the available data, it is therefore clear that Agni-II has a maximum range of somewhere in excess of 3000 km, and possibly as high as 3500 km with a 1000 kg payload. Greater range with a lighter payload however requires the RV to be qualified for higher re-entry velocity and corresponding Max-Q for thermal stress[66]. As the backbone of the Indian land-based nuclear deterrent, the real significance of the Agni-II is the fact that it is both road and rail mobile. This is an indication of India's desire not to put its missiles into vulnerable silos. The mobility of the Agni-II, combined with the sheer physical size of India renders the mobile IRBM a very secure and survivable delivery system. Furthermore, Raj Chengappa asserts that one of Agni-II missiles was tested with a nuclear weapon assembly - minus the plutonium core - mounted in the warhead assembly area to ensure that all systems, including safety locks, would work[67].

Mobile Launcher

Agni-II is road mobile as well as rail mobile. The rail mobile system has an integrated launcher along with command and communication system. Rail mobile launcher platform is a 27m long special purpose wagon on broad gauge. It houses tilt beam, transportation support, mating, integration and erection support. It is capable of performing all the operations required at launch sites. A payload integration device has been provided to facilitate payload changing from conventional to nuclear and vice versa. 

The rail wagon/platform is leveled by five sets of hydraulic actuator/outrigger cylinders. Leveling is done remotely to an accuracy of ±0.1° and the mission-critical first-stage support arm assembly clears the path of missile within 200 ms[68].

Agni-II Configuration

  Agni-II Stage 1 Agni-II Stage 2 PBV/HAM RV

Gross Mass

Fuel Mass

Empty Mass

Fuel-Mass-Ratio[69]

10,800 kg

9342 kg

? kg

0.865

4200 kg

3570 kg

? kg

0.85

220 kg

40 - 180 kg

20 - 50 kg

0.82

50 kg

.

.

Thrust @ Vacuum
Thrust @ Sea Level
(Burn Time)

51,251 Kgf

46,390 Kgf

(49 seconds)

27,227 Kgf

-

(32 seconds)

50 Kgf

-

-

Not Applicable

.

.

Specific-Impulse

ISP @ Vacuum

ISP @ Sea Level

 

259 seconds[70]

232 seconds

 

276 seconds[71]

220 seconds

 

306 seconds[72]

-

Not Applicable

.

.

Length

Diameter

10.3 meters

1.0 meter

4.8 meters

1.0 meter

2.3 meters

0.8 meters

2.2 meters

0.8 meters

.

.

Chamber Pressure[73]

Expansion Ratio

44.1 bar

6.7:1

38.3 bar

14.2:1

? bar

?

Not Applicable

.

.

Propellant

Chemical

Case Material

Solid

HTPB/AP/Al

15CDV6 steel

Solid

HTPB/AP/Al

250 Maraging Steel OR filament wound composite 

Liquid

MMH/N2O4

Titanium pressure tank OR solid fuelled cartridge motor

Not Applicable

Not Applicable

All Carbon Composite

.

.

Number of Engines

(Number of Segments)

1

(3)

1

(1)

1

(-)

Not Applicable

.

INTRODUCTION: AGNI-I

The Agni-I is a single stage version of the Agni-II missile. It stands at 15 metres, weighs 12 tons and serves as a medium range ballistic missile. The missile was rapidly developed after Kargil War when the need for an intermediate range missile – addressing the range gap between the Agni-II and the Prithvi[74]. On the western front, the range of the Prithvi-I/II was found too short for strategic use and the Agni-II had too long a range, requiring prolonged flight over Indian territory, and requiring lofted or depressed launch angle beyond usual limits, thus degrading accuracy. The Agni-I is effectively the Agni-II minus it's second stage. However this configuration puts greater 'G force' stresses on the RV and avionics, when the stage completes (about 18G instead of Agni-II's maximum of ~9G) its journey. The missile has been extensively fight tested.

Indian Government reports state the range to be between 700 to 890 km[75] with a 1000 kg payload. With a special weapons load, Agni-I can reach 1200 km. The first test, from a road-mobile launcher, was conducted on 25 January 2002 to a range of 700 km and was termed an accurate and successful flight that met its mission objectives. A second test followed on 09 January 2003. The missile was then cleared for service in the Indian Army[76]. Agni-I can carry a one ton conventional or nuclear payload to most targets in Pakistan without having to be deployed at the borders. The core and triggers can be swiftly assembled by BARC (Bhaba Atomic Research Centre) and DRDO (Defense Research & Development Organisation) - within India's avowed no-first-use paradigm.

Agni-I is also designed to be launched from a rail-based mobile launcher; one that can move on a standard broad-gauge rail system and also from a road-mobile launcher system. DRDO's Ahmednagar-based VRDE (Vehicle Research & Development Establishment) and the Pune-based R&DE (Research & Development Engineers) played important roles in validating the tractor-cum-transporter-cum-launcher. A mobile missile system reduces vulnerability and allows for greater operational flexibility, while critics feel that the cost of these mobile systems could be higher and that they greatly increase the time for moving from one place to another.

The control over the 700-km-range Agni A-I missile is expected to pass on to the 334th and 444th missile groups of the Indian Army. These groups along with the 335th missile group is likely to be entrusted with various Agni variants. No official confirmation is available about these two missile groups. It is also unclear whether their control could pass on to the Strategic Force Command (SFC), recently created to handle the country's nuclear delivery assets[77].

.

Image © PVS Jagan Mohan

Agni-I mounted on a TEL
[Image
© PVS Jagan Mohan] 

Image © DRDO

Agni-I on launch pad (second test) on 09 January 2003.

[Image © DRDO] 

Image © DRDO

Agni-I second test rollout 

[Image © DRDO] 

.

Image © DRDO

Agni-I second test ignition on
09 January 2003.

[Image © DRDO] 

Image © DRDO

The rail-mobile Agni-I being
wheeled out.

[Image © DRDO] 

Image © DRDO

Agni-I on a road-based mobile, transporter cum erector cum launcher. 

[Image © DRDO] 

.

Image © Press Information Bureau

Agni-I at Republic Day Parade.

[Image © Press Information Bureau] 

Image © DRDO

Agni-I at Republic Day Parade,
26 January 2004.

[Image © DRDO] 

Image © DRDO

Agni-I at Republic Day Parade
Rehearsal - 2005.

[Image © DRDO] 

.

Image & Analysis © Arun Vishwakarma

Range of the Agni-I against Pakistan, at ranges of 700 km,
860 km and 1200 km
[Image & Analysis © Arun Vishwakarma] 

Description

Avionics: Similar to Agni-II. DRDO's Chief Controller of R&D (Missiles), Dr A S Pillai, stated that Agni-I incorporates new guidance & control systems and there was also significant improvements in its re-entry technology and manoeuvrability. With only one stage, the weight is less but the thrust is the same, giving the missile more acceleration.

Manoeuvring Re-Entry Vehicle: Agni RV-Mk.? Same as Agni-II. However some test launch photos show that some RV configurations without manoeuvring fins.

Propulsion: Single stage rocket configuration.

First Stage: Similar to Agni-II's first stage.

Agni-I Configuration

  Agni-I Stage 1 PBV/HAM RV

Gross Mass

Fuel Mass

Empty Mass

Stage Fuel-Mass-Ratio[78]

10,800 kg

9,342 kg

? kg

0.865

220 kg

40-180 kg

20-50 kg

0.82

50 kg

-

-

-

.

 

Thrust @ Vacuum
Thrust @ Sea Level
(Burn Time)

51,251 Kgf

46,390 Kgf

(49 seconds)

50 Kgf

-

-

Not Applicable

.

 

Specific-Impulse

ISP @ Vacuum

ISP @ Sea Level

259 seconds[79]

232 seconds

306 seconds[80]

-

Not Applicable

.

 

Length

Diameter

10.3 meters

1.0 meters

2.3 meters

0.81meters

2.2 meters

0.8 meters

.

 

Chamber Pressure[81]

Expansion Ratio

44.1 bar

6.7:1

? bar

-

Not Applicable

.

 

Propellant

Chemical

Case Material

Solid

HTPB/AP/Al

15CDV6 steel

Liquid

MMH/N2O4

Titanium pressure tank

Not Applicable

Not Applicable

All Carbon Composite

.

 

Number of Engines

(Number of Segments)

1

(3)

1

(-)

Not Applicable

.

INTRODUCTION: AGNI-IIAT

The Agni-II was a quick and proven design, albeit of 1980s vintage. The Agni-IIAT is the result of a CIP (Continuous Improvement Program) with Agni-II. Different reports indicate India developing a more advanced technology (AT) version of Agni-II[82] putting into use, state-of-the-art technologies to significantly improve the Agni-II performance[83] as well as to adapt it to the newer and lighter nuclear payload, that was proven by the Pokharan-II series of nuclear tests[84]. The new propulsion system could  greatly increase the missile's range to 4000 km (1500 kg payload) and potentially to ICBM range for lighter payload. 

The Agni-IIAT is likely to incorporate the following changes:

  1. A larger diameter booster stage made of stronger 250-Marging steel, improving fuel loading and fuel mass-fraction (~0.88).

  2. Lightweight carbon composite motor casing[85, 86] for the second stage, instead of steel casing, improving its mass-fraction (~0.92).

  3. Lighter, tougher and higher β (beta) RV, with all carbon composite re-entry heat-shield, multi directional carbon re-entry nose tip and control surfaces[87]. Very likely a unary version of the Agni-III's RV Mk-4.

We refer to this postulated configuration as Agni-IIAT that would be validated when it is tested sometime in the future[88]. However this paper gives an insight to potency of such technological improvement.

NEW IMPROVED COMPONENT: (From left): M. Natarajan, Scientific adviser to Defence Minister, Tessy Thomas, project director, Advanced System Laboratory (ASL) and Avinash Chander, Director, ASL, at the Ramakrishna Engineering Company in Chennai on Thursday. — Photo: the HINDU, 10-Nov-06.

Image © Advanced Systems Laboratory (ASL), Hyderabad

Comparative Line drawing of Agni-II and Agni-IIAT    

[Image © Arun Vishwakarma]  

New improved 1.2m diameter rocket case of maraging steel being handed over to M. Natarajan  

[Source: The HINDU, 10-Nov-06]

Composite casing of Agni-II's second stage

 [Image : Advanced Systems Laboratory, Hyderabad] 

Description

After Agni-II development DRDO has reported major success in developing superior sub-systems ranging  from  newer higher performance RV, lighter casing of second stage and booster case made of stronger Maraging steel. The new missile's form factor is almost same as the Agni-II, but qualitative improvements in propulsion and warhead significantly improves its range and effectiveness.

Accuracy of this longer range missile is augmented by space based precision navigation system. India and Russia are working together on the development and launch of a new generation of Global Navigation Satellite System (GLONESS) that will be operational by 2007[89]. India is also building its own IRNSS (Indian Regional Navigation Satellite System)[90] covering 35% of earth surface, centered around India for assured access to space based precision navigation.

Manoeuvring Re-Entry Vehicle: 

New lighter and tougher RV, with all carbon composite re-entry heat shield with multi directional carbon re-entry nose tip and control surfaces, the new lightweight composites can withstand temperatures of up to 6,000º centigrade, thus capable of greater re-entry velocity[91, 92]. The new RV smaller in diameter & length but higher β (beta) compared to the RV of Agni-I/II, similar to RV-MK4 of Agni-III & Agni-III++.

Propulsion

First Stage: A new 1.2 meter diameter[92.A] booster case made of 250-Maraging steel with improved chamber pressure and fuel mass-fraction (estimated 0.88). Approximately 12 meter long and 20 tonne mass

Second Stage: Lightweight filament wound carbon composite motor casing[93, 94] for Stage-II with improved fuel mass-fraction (estimated between 0.90 - 0.92[95]).

Agni-IIAT Configuration

  Agni-IIAT Stage 1 Agni-IIAT Stage 2 PBV/HAM RV

Gross Mass

Fuel Mass

Empty Mass

Fuel-Mass-Ratio[96]

20,000 kg

17,600 kg

2,400 kg

0.88

6,000 kg

5,400 kg

600 kg

0.90

220 kg

40 - 180 kg

20 - 50 kg

0.82

50 kg

.

.

Thrust @ Vacuum
Thrust @ Sea Level
(Burn Time)

78,600 Kgf

70,400 Kgf

(58 seconds)

42,580 Kgf

-

(35 seconds)

50 Kgf

-

-

Not Applicable

.

.

Specific-Impulse

ISP @ Vacuum

ISP @ Sea Level

 

259 seconds[97]

232 seconds

 

276 seconds[98]

220 seconds

 

306 seconds[99]

-

Not Applicable

.

.

Length

Diameter

12 meters

1.2 meter

4.8 meters

1.2 meter

-

-

2.6 meters

1.0 meters

.

.

Chamber Pressure[100]

Expansion Ratio

44.1 bar

6.7:1

38.3 bar

14.2:1

-

-

Not Applicable

.

.

Propellant

Chemical

Case Material

Solid

HTPB/AP/Al

250-Maraging Steel

Solid

HTPB/AP/Al

Filament wound
composite material

Liquid

MMH/N2O4

Titanium pressure tank
OR solid fuel composite case

Not Applicable

Not Applicable

All Carbon Composite

.

.

Number of Engines

(Number of Segments)

1

(3)

1

(1)

1

Not Applicable

-

Not Applicable

.

INTRODUCTION: AGNI-III 

Indian doctrine of Minimum Credible Nuclear Deterrence envisages "No First Use" (NFU) policy and a triad of nuclear counterstrike capability.  The Prithvi, Agni-1, Agni-II are land based missiles with range limited to about 3,500 Km. India requires few types of long range missiles to provide robust second strike capability. Missiles that can be dispersed far and wide in the Indian mainland, it's far flung islands or it's blue water naval assets dispersed across the world's oceans. The ability to reach all corners of a potential challenger, requires a missile range of between 5000 to 8000 km. 

India is developing a series of Agni missiles with larger motor diameter, capable of heavier payload and longer range. This development is also driven by need for a more assured retaliation that can defeat emerging ABM defenses and countermeasures. Such capability requires a heavy but compact missile that can carry ABM counter measure payloads along with weapons, in a configuration similar to MIRV.

The successor to the Agni-II and the ultimate development of the Agni family is the Agni-III. This missile also fulfills India's immediate deterrent requirements against the People's Republic of China (PRC). Some of the following is estimated based on available news reports and anticipated features based on India's security concerns and capability. On 17 May 2006 DRDO publicly announced the  existence of the missile and issued a short video clip. 

Agni-III test was postponed 3 times ostensibly to rectify some technical issues as well as geo-political constrains[101]The missile was first test fired on 9 July 2006, but the missile failed to fully meet mission objectives[102] ostensibly due to cascaded failure of booster flex nozzle controller and flight control system. The root cause can be fixed with relatively simple modifications and follow on test flights scheduled for first quarter of 2007. Initially just 3 missile tests were planned before entering service in 2008[103], but in light of maiden test flight failure more test flights will now be required to prove its robustness. The missile cost is about 1/6th of similar missile developed by western countries.

Description

In the Agni tribe, Agni-III is a family of large diameter, solid fuel missiles. They are compact and small enough for easy mobility and can be easily packaged for deployment on variety of surface/sub-surface platforms. The 44 tonnes (eventually up to 48 tonnes) Agni-III has solid fuelle stages with an overall diameter of between 1.8 - 2.0 meters[104]. The Agni-III is a 2 stage 14.5m long missile with a unary RV payload. The first stage is approximately 6.6 meters long and the second stage about  2.7 meters long with a 1 meter vented inter-stage.

The missile will support a wide range of warhead configurations, with total strategic payload mass ranging from 600 kg to 1,800 kg[105]. High missile accuracy permits effective use by using conventional warhead reportedly ranging between 2490 -3490 Kg. This makes it useable in smaller sub-nuclear conflicts, a trend now seen in American long range missiles.

Image © DRDO

Agni-III family size v.s. Agni-II & Project K-15 underwater launcher
[Line drawing
© Arun Vishwakarma] 

Agni-III on transfer crane[106]  

[Courtesy DRDO, Image Via: CNN-IBN]

Pontoon underwater launching platforms for Project K-15

  [Image © DRDO] 

Agni-III will likely serve as a base missile around which variant will be built. One can expect a underwater launched version Agni-3SL that is short enough (~12 meter) to be carried in future Indian submarines.  The MIRV payload compartment is certain to arise to make use of the colossal payload capability to provide a great flexibility to serve a range of military requirements. A version with an added3rd stage will greatly increase the range.  

Manoeuvring Re-Entry Vehicle: Agni RV-Mk.3

Agni-III RV supports a wide range of weapons, with total payload mass ranging from 600 kg to 3,490 kg including decoys and other ABM countermeasures. The missile range is a function of payload (see Range-Payload graph below).

RV configuration & packaging comparison 
[Line drawing
© Arun Vishwakarma] 

Unlike Agni-I & Agni-II RV that is sub-optimal & force-fitted solution[107] to carry the lighter Thermonuclear payload that were tested in 1998, the RV-Mk3 is the first RV that is designed & optimized for the new lighter 200Kt thermonuclear payload weapon and corresponding long range[108]. The 200Kt yield weapon reportedly weighs less than 450 Kg, however other sources indicate a mass of between 300 to 200 Kg[109].  

Agni-III with single new warhead requires a bigger RV body that can adapt with the large diameter motor. Compared to Agni-II this RV is shorter, more voluminous and 3.3 meter long. The large base diameter makes it unviable for high speed reentry, thus this could be a payload adapter section that jettisons the real RV located in the front part. The high ‘β’(Ballistic coefficient[110]) RV in combination with an all carbon composite body enables higher re-entry speed even with a light weight payload. The sharp high ‘β’  RV-Mk.3 design employs distinctly smaller 17 cm diameter blunt nose about 1.7 meter long and half angle of 10°. The high ‘β’ RV in combination with an all carbon composite body enables higher re-entry speed even with a light weight payload[111]. Like the RV Mk-2 it is also carries velocity correction package. It is perhas world’s first all composite RV and uses no metal backup[112]. The all carbon composite re-entry heat shields with multi-directional ablative carbon-carbon re-entry nose tip[113] make it very light and tough. The new lightweight composite case can withstand temperatures of up to 5,000º C[114]thus its conic half angle choice is more aggressive, yet capable of all possible re-entry velocities. This very light RV mass uniquely enables large increase in missile’s range. The new RV has been flight tested on another platform before its use on Agni-III[115]

DRDO is reportedly working on MIRV[115A] for other large diameter Agni variants. 

Propulsion

The Agni-III has two solid fuelled stages of 1.8 to 2.0 meters diameter. This diameter is compatible with a recently tested Indian sub-surface launch system, that has a 2.4 meter diameter launch tube[116]. Booster stage uses lightweight composite material case to achieve high fuel mass fraction that is necessary for a small but long range missile. the second stage case is made of maraging steel that will eventually use light weight composites. Thus  initial Agni-3 version would see payload capability degraded by about 450 Kg.

 

First Stage

The first stage is approximately 30 tonnes mass and length of 6.6 meters. This stage's specific impulse (ISP) of 237/269 is believed to be better than Agni-II booster and closer to large solid motor currently in use on Indian space launchers. The stage has 22 tonnes (approx) of high -energy solid fuel and 75 seconds burn time. Composite material case reduces the dead weight increasing its propulsion efficiency. It employs flex nozzle for yaw, pitch and roll thus dispenses with air fins, enabling container stowage & launch. This is the first Indian use of flex nozzle solid fuel stage for booster stage[117] allowing greater flight control during the ascent through dense atmosphere including the maximum-Q point approximately 30 seconds into the flight. 

Second Stage

The 1 meter long vented interstage is light-weight and ensures better vehicle control and reliable second stage separation. The second stage mass is about 12 tonnes and length of 4.2 meters (including 0.8 m payload adapter). The stage currently employs maraging steel case that will be later upgraded to composites to maximize fuel mass fraction that is critical to realize long range, especially with lighter payload. The second stage has flex nozzles to provide necessary in-flight trajectory control. The high energy solid fuel of the stage burns slowly for about 105 seconds using high expansion ratio nozzle making it a very efficient engine. The engine performance is similar to HPS3 used in Indian space launchers.

Agni-III Configuration: 

Few  parameters below are estimated based on available news reports, trade practice and known Indian capability

  Agni-III Stage 1 Agni-III Stage 2 RV

Gross Mass[118]

Fuel Mass

Empty Mass

Stage Fuel-Mass-Ratio[119]

30,500 kg

27,750 kg

2,750 kg

0.91

12,000 kg

10,440 kg

1,560 kg

0.87

50 kg

-

-

-

.

 

Thrust @ Vacuum[120]

Thrust @ Sea Level[121]

(Burn Time)[122]

97,500 Kgf

87,750 Kgf

(75 seconds)

27,900 Kgf

18,000 Kgf

(110 seconds)

Not Applicable

.

 

Specific-Impulse

ISP @ Vacuum

ISP @ Sea Level

269 seconds[123]

237 seconds

294 seconds[124]

190 seconds

Not Applicable

.

 

Length[125]

Diameter[126]

6.6 meters

1.8 meters[127]

2.7 meters

1.8 meters[128]

3.3 meters

1.8 meters

.

 

Chamber Pressure[129]

Expansion Ratio[130]

58 bar

8:1

60 bar

50:1

Not Applicable

.

 

Propellant

Chemical

Case Material

Solid

HTPB/AP/Al

Kevlar Epoxy Composites

Solid

HTPB/AP/Al

Maraging steel

Not Applicable

Not Applicable

All Carbon Composite

.

 

Number of Engines

(Number of Segments)

1

(2)

1

(1)

Not Applicable

 

Navigation & Accuracy

Agni-III largely carries the proven avionics set of Agni-II, however, in view of its longer range, it is augmented by a new true-inertial platform based Inertial Navigation System (Earlier IRBM's used Strap-down Inertial Measurement Unit). With joint Indo-Russian revival of GLONASS, India will have access to military grade precision[131] that will be very useful for all Indian missiles. Agni-III will also benefit form Indian Regional Navigation Satellite System (IRNSS)[132] when it is ready in 2012[133], to ensure guaranteed national access to precision navigation. These systems enable unprecedented accuracy to Agni missiles in a conventional role.

Agni-III Range vs Payload

Missile range & payload mass are inversely related. It is useful to contrast the variation between Agni-III and Agni-II. It is interesting to note that Agni-III with its larger mass fraction design has a greater capability and sensitivity for lighter payload, where as Agni-II is not very sensitive for lighter payload. Of course Agni-III is a heavier missile compared to Agni-II thus offers a broader payload range. Initial Agni-3 version uses second stage case made of maraging steel, incremental dead weight increase of ~450 Kg shall translate to effective mass of payload increase by same quantum. Further improvement in second stage fuel-mass fraction could improve the capability for lighter payload significantly.

Range versus Payload of Agni-III & Agni-II

[Analysis © Arun Vishwakarma]


INTRODUCTION: AGNI-IV

The two stage Agni-III would eventually evolve to a full range ICBM by addition of a third stage (approx 2,000kg mass). The 14 meter tall Agni-IV would weight about 50 tonnes. India may soon test[134] Agni-IV.  There is pressure of tenuous global geo-political situation with high risk of regional war for which Indian should be fully prepared.

Re-Entry Vehicle (MIRV)

Essentially same as the Agni-III SL and qualified for full range of re-entry speed and stress in MIRV[134A] configuration. The MIRV bay will be protected by a light payload faring that will be jettisoned at 90-100Km altitude. 

Propulsion

The Agni-IV will employ three solid fuel stages. 

First Stage: The first stage same or similar to that of Agni-III.

Second Stage: A composite fiber case construction that is otherwise similar to second stage of Agni-III.

Third Stage: A new stage of approximately 2.3 tonnes, length of 1 meters and flex nozzle for trajectory control. Composite case construction to get high Fuel Mass Ratio.

Agni-IV likely configuration.
[Image
© Arun Vishwakarma]

Shakti-1 Thermo-Nuclear weapon during 1998 Pokhran-II nuclear tests. [Image: Govt. of India]

Notional old and new Indian strategic weapon shape & size

[© Arun Vishwakarma] 

Warhead Options

India's nuclear warhead options are still relatively limited, though quite perfectly adequate. Since the first Peaceful Nuclear Explosion (PNE) in 1974 (PoK-I), India adopted the recessed deterrence posture initially consisting of fission weapons (~15 KT yield) followed by boosted fission weapons of 200 KT yield, suitable for the Agni-TD/TTB. The PoK-II 1998 'Shakti' series of nuclear tests in Pokhran were reportedly done to validate multiple weapon designs, of 1995 vintage. Interestingly the 200 KT boosted fission design of 1980 was not tested in PoK-II, ostensibly having long given way to a lighter and more efficient S1 design. It is interesting to note that India has access to large quantities[135] of Tritium - produced at an extremely low cost - which lends flexibility to Indian weapon design options, an option that is not available or viable to prior nuclear weapon states.

  Weapon Fission Fuel Yield (KT) Weight (kg) Note
1 High yield, thermonuclear (Plutonium [Pu], Deuterium & Tritium)[136] Pu (WpnGrd)[137] 200 - 300 < 500

• Shakti-I test at Pokharan-II (PoK-II)
• Boosted fission primary of ~20KT
• Approximately 300 kg mass
• Plutonium based boosted primary stage. Li-D secondary
• Unknown Fusion Spark Plug (Pu/U235)

. .
2 Medium yield, fusion boosted fission Pu (WpnGrd) 15 - 20 < 200

• Primary stage of Shakti-1 test at PoK-II
• Standard medium yield weapon

. .
3 Medium yield, pure fission Pu (WpnGrd) 15[138] 170 - 200

• Shakti-2 test at PoK-II
• This was tested from a weapon stockpile. Almost certainly superseded by a fusion boosted fission version, described above (item 2).

. .
4 Low yield, sub-KT Pu (WpnGrd) 0.1 to 1 < 200 (est.)

• Battlefield Weapon

. .
5 Low yield, sub-KT[139] Pu or U233
(RctrGrd)
[140]
0.3 to 1 < 200 (est.)

• Reactor Grade Pu or U233

The primary warhead for the Agni family would be a 200-300 Kt fusion weapon based on the Shakti-1 (Pokhran-II) test in 1998. The fusion weapon based on the S-1 design, would have a mass of some 500 kg, based on the 450 kg mass of the 45kT demonstration test, which used an inert mantle[141]. It has also emerged that by 1982, the BARC/DRDO team had produced a design for a (pure) fission device that weighed between 170 and 200 kg for a yield of 15 KT - a huge change from the 1000 kg monster tested in 1974[142]. This would mean that a missile warhead based on this 1982 vintage design would weigh some 250 - 350 kg. Therefore, when considering the range and payload parameters of the Agni and Prithvi missiles, these figures must be borne in mind.

Production and Deployment[143]

If the confusion regarding the range and guidance systems of the Agni-II, seem like excessive prying on the part of the overly-curious writers, the issues regarding the production of the Agni-II and its induction into the armed forces is not so easily dismissed. Prior to the first test of the Agni-II, press reports emerged of facilities being created to produce between 10 and 12 Agni-II missiles per year - a figure sometimes reported as between 12 and 18 missiles per year. However, it is entirely unclear as to whether any such production facilities have been created. Both Jaswant Singh and George Fernandes (during their tenures as Defense Minister) have claimed that the Agni-II is in production and is being inducted - apparently by the 335th Missile Group of the Regiment of Artillery. What is unclear is whether sufficient equipment and reloads exist to make 335 Missile Group operational. If production on the scale envisaged had commenced in 2001 - 2002, some 12+ launchers and 24+ missiles should exist.

However, there has been no indication either from DRDO or BDL as to whether any production on that scale is in progress. Rather surprisingly, India has not proceeded with the test of the Agni-III and has opted to commence production of the Agni-II IRBM - entering service with 335th Missile Group - and to prepare for production of the Agni-I which is to enter service with 334th Missile Group[144]. Each Agni missile group will have some 8 launchers and at least as many missiles. Delivery of the Agni-II commenced in 2001 - 2002 and the system should be fully operational with the Army by now. Even if production was ridiculously low, a figure of 18 to 24 Agni-II missiles should have been produced by now. However, the Agni-I entered service somewhat later and it would be surprising if more that 8 missiles were currently available for deployment.

Yet, one cannot help but notice a marked lack of vigour on the part of the Government on getting these groups operational and to testing the Agni-III - much less develop ICBMs. Dr. Aatre's comments on the pending Agni-III test make one wistful for the reality[145]. Indeed, as far as the incoming government is concerned, this should be the major strategic priority. At present, it can be assumed that India's land-based missile deterrent is based around:

Agni - Test Flight Chronology

  1. May 22, 1989: Agni-01.

  2. May 29, 1992: Agni-02 Failure[147] at ITR Chandipur.

  3. February 19, 1994: Agni-03[148].

  4. April 11, 1999: Agni-II-01 @ 09:47 a.m. IST at Launch Complex IV on Wheeler's Island. Rail-mobile platform[149].

  5. January 17, 2001: Agni-II–02 at ITR Chandipur.

  6. January 25, 2002: Agni-I (SRBM) at ITR Chandipur.

  7. January 9, 2003: Agni-I at Wheeler's Island.

  8. July 4, 2003: Agni-I at Wheeler's Island.

  9. August 29, 2004: Agni-II-03 @ 12:55 p.m. IST at Launch Complex IV on Wheeler Island. Mobile launcher platform. Target Range: 1200 km using a lofted approach[150].

  10. June 9, 2006: Agni-III @11:03 a.m IST at Wheeler's Island (Failure).

Related Articles

  1. Indian Long Range Strategic Missiles - Indian Defense Review Oct-Dec 2006 Vol 21(4), by Arun Vishwakarma.  ,

  2. Evaluating India's land-based Missile Deterrent - Security Research Review Vol-1(3) April 2005; Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

  3. Agni-III Long Range Missile - Indian Defense Review Apr-Jun 2006 Vol.21(2), ISSN 0970-2512 Arun Vishwakarma. Lancer Publishers & Distributors, New Delhi.


Note of Thanks:

The author thanks Dr Sanjay Badri Maharaj for his review and inputs.  

Sources 

  1. Evaluating India's land-based Missile Deterrent. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

  2. Raj Chengappa, Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India, 2000, ISBN 81-7223-332-0).

  3. India's Emerging Nuclear Posture, Ashley J.Tellis OXFORD University Press. ISBN 019565905-8

  4. Defence Research & Development Organization (http://www.drdo.com/)

  5. DRDO periodicals "Technology Focus" bi-weekly (www.drdo.com/pub/techfocus/welcome3.htm)

  6. Indian Defence Technology: Missile Systems (DRDO, Ministry of Defence, December 1998).

  7. Nuclear Threat Initiative (http://www.nti.org/)

  8. http://www.nbr.org/publications/analysis/pdf/vol13no3.pdf  VOLUME 13, NUMBER 3, JUNE 2002. “Ballistic Missiles and Missile Defense in Asia”

  9. Nuclear Weapon Archive, 'India's Nuclear Weapons Program: Present Capabilities'
    http://nuclearweaponarchive.org/India/IndiaArsenal.html

  10. Composites: Use in saucepan handles, artificial limbs and the AGNI CURRENT SCIENCE, VOL. 86, NO. 3, 10 FEBRUARY 2004 http://www.ias.ac.in/currsci/feb102004/372.pdf 

  11. A success story T.S. SUBRAMANIAN, Frontline Volume 22 - Issue 20, Sep. 24 - Oct. 07, 2005 http://www.hinduonnet.com/fline/fl2220/stories/20051007002009200.htm

  12. 'DRDO Missile Launching platform', DRDO Technology Focus Vol. 12 August 2004 No. 4 http://www.drdo.com/pub/techfocus/aug04/welcometfaug04.htm

  13. “A study of the motion and aerodynamic heating of ballistic missiles entering the earth’s atmosphere at high supersonic speeds”, Report 1381- National Advisory Committee For Aeronautics, NASA.

  14. Ballistic Missiles and Missile Defense in Asia ,  NBR Analysis, VOLUME 13, NUMBER 3, JUNE 2002. www.eurasia.nbr.org/publications/analysis/pdf/vol13no3.pdf  

  15. Agni-III Long Range Missile, Indian Defense Review Apr-Jun 2006 Vol.21(2), ISSN 0970-2512 Arun Vishwakarma. Lancer Publishers & Distributors, New Delhi .


References

[1'India has tech to go beyond Agni-III',  The Hindu Business Line Friday, May 20, 2005 

[2] "The then principal scientific advisor to the Indian government, Dr. Abdul Kalam, revealed that contrary to popular perceptions, the Agni project was never stopped; rather all governments supported it. He also states that the Agni's import content is less than 10% and India now has the indigenous capability to design, develop, and produce any type of missile. When asked if it was feasible to declare the Agni-II operational after a single test, he stated that India has data from three previous tests of the Agni-I and 16 flight-tests of the Prithvi. In addition, the simultaneous monitoring of over 600 test parameters and ground simulation technologies obviate the need for multiple flight-tests. He also states that the Agni was "never conceived only as a nuclear weapon system. What it did was to afford us [India] the option of developing the ability to delivery non-nuclear weapons with precision at long ranges. That it provided us with a viable non-nuclear option, was of the greatest relevance to contemporary strategic doctrines." — Interview: Dr. APJ Abdul Kalam, India Today (New Delhi), 26 April 1999, http://www.india-today.com/

Dr. Kalam with Arun Tiwari, in 'Wings of Fire: An Autobiography', (Hyderabad: Universities Press (India) Limited, 1999), p.153.

[3] 'Agni-III test likely by year-end' RAJAT PANDIT,  The Times of India TIMES NEWS NETWORK JANUARY 11, 2003. "The solid-fuelled 'Agni-III' will be both road and rail-mobile to confer operational flexibility in deployment. It will be an entirely new vehicle, along with a true inertial navigation system, to accord capabilities to deliver a one-tonne warhead beyond the range of combat aircraft."    

India to test-fire Agni-III soon - The Times of India RAJAT PANDIT, TIMES NEWS NETWORK JANUARY 01, 2004 "The solid-fuelled ‘Agni-III’, which will be both road and rail-mobile to confer operational flexibility in deployment, was initially to be tested towards end-2003 but it ran into technical problems. The snags in this two-stage missile, with a ‘‘true’’ inertial navigation system, have now been rectified"

[4] India To Test Launch Agni-3 Missile In Next Five Months, New Delhi, India (PTI) Jul 05, 2005 www.spacewar.com

India ready to fire long-range Agni-III missiles Press Trust of India HindustanTimes.com May 14, 2006 

[4.A]"India preparing to test 1st ICBM, New missiles will have eventual range of over 12,000 miles" Jon Dougherty, WorldNetDaily.com MAY 6, 2001. " India is preparing to test a new class of intercontinental ballistic missiles, beginning in January 2002, with one missile said to have a maximum range of over 12,000 miles. Indian media reports said the first ICBM, the Surya (Agni IV), with a range of 5,000 kilometers (3,100 miles) will begin flight testing in January, followed by a longer-range version, the Surya II, to begin testing in 2003.The Surya II, reports said, will have a range of 12,000 kilometers (7,500 miles), according to officials at India's Defense Research and Development Organization". http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=22706

[4.B] 'India ready to fire long-range Agni-III missile' Press Trust of India, HindustanTimes May 14, 2006 

[5] 'Development of Solid Propulsion Systems for Guided Missiles' in H.S. Mukunda and A.V. Krishnamurty, eds., Recent Advances in Aerospace Sciences and Engineering (Bangalore: Interline Publishing, 1992), p.182;  Raj Chengappa, "Not So Valiant". Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India, 2000), p.161.  

Raj Chengappa, "The Devil's Workshop," Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India, 2000), pp.169-171; "Category I-Item II: Complete Subsystems," Missile Technology Control Regime Annex Handbook, pp.2-11-2-12; Dr. N.C. Birla and B.S. Murthy, eds., "Inertial Guidance and Sensors," Indian Defence Technology: Missile Systems (DRDO, MoD, December 1998), pp.155-156.

[6] Gordon, India's Rise to Power, p.87

[7] Ibid p.88

[8] Raj Chengappa, "Caught in the Crosshairs," Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000), pp.371-372.

[9] "Missile Chronology 1986-1990", NTI (Nuclear Threat Initiative).

[10] Raj Chengappa, 'The Missile Man', p.40. While there were reports in 1993 that were highly sceptical of India's ability to test such a system, there have been none since the actual test.

[11] Sawhney, 'Standing Alone', p.28. This system would be difficult, though not impossible, to evaluate over water.

[12] Raj Chengappa, 'The Missile Man' p.42.

[13] 'Indigenous Missile Development Program to Continue', India Abroad: 30 August 1996, p.21.

[14] April 28, 1995: Prime Minister Narasimha Rao refutes allegations that India has capped its missile program under US pressure. Replying to a debate in parliament, Rao asserts that India will not buckle under anybody's pressure, as far as it's defense preparedness is concerned. — Pravin Sawhney, "Army Organizes First Prithvi Missile Unit," Asian Age (New Delhi), 29 April 1995, p.1, in FBIS Document FBIS-NES-95-083, 1 May 1995, pp.45-46.

[15]  "Annual Report," Ministry of Defence, Government of India, 1994-1995, p.39; Raj Chengappa, "Nuclear Policy: Making Compromises," India Today (New Delhi), 30 April 1995, p.36; Raj Chengappa, "Boom for Boom," India Today (New Delhi), 26 April 1999, http://www.india-today.com/.

[16] May 11, 1998: An Indian defense official reveals that contrary to popular perceptions that India had put its Integrated Guided Missile Development Program (IGMDP) on hold under US pressure, the projects were never capped completely. The official stated, "How can we stop working on it? We cannot take a risk of reaching in a stage of technology-gap ... capping the missile program at this stage means creating a considerable technological gap, and India cannot afford to do that keeping in mind India's war-history." DRDO sources suggest that Pakistan's Ghauri has given the country [India] a golden opportunity to legitimize R&D on the sophisticated missile projects. — "Agni project was never capped," The Hindu (Chennai), 11 May 1998, http://www.hinduonnet.com/.

[17] April 13, 1995: After a visit to the Defense Research & Development Laboratory (DRDL) in Hyderabad (Andhra Pradesh), Prime Minister Narasimha Rao sanctions approximately 6 billion rupees for the development of the Agni program. He also orders the DRDO to speed up efforts to build nuclear weapons and set up a nuclear command and control system for the safe custody, deployment and employment of such weapons. DRDO Chief, Dr Kalam sets up a special cell to ensure that nuclear cores at the Bhabha Atomic Research Center (BARC) in Trombay are scattered to several sites in the country to enhance their survivability; that the mechanism to ensure the mating of the core with the bomb assembly is achieved in the shortest time frame; that the command to trigger nuclear weapons remains under civilian control; and that it is a system that will win consent of at least three agencies to arm nuclear weapons. — Raj Chengappa, "Tell Your President, I Keep My Word," Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000), p.391.

[18]Indian scientists allegedly ready four Prithvi and at least one Agni missile for possible nuclear counter-strikes against Pakistan during the Kargil border conflict. The missiles are activated to a state known as Readiness State-3. In this stage, warheads are kept ready to be mated with missiles at short notice. Indian scientists arm one Agni missile with a nuclear warhead during the Kargil conflict with Pakistan. The missile is allegedly deployed somewhere in Western India. — Raj Chengappa, "The Earth Broke Under Our Feet," Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power, (New Delhi: Harper Collins Publishers, 2000), p.437.

[19] Agni Achieves Operational Status. Vivek Raghuvanshi, Defense News, 04 September 2000, p.32. http://www.nti.org/db/missile/2000/m0011151.htm

[20] Author's conversation with DRDO personnel at Aero-India 2005.

[21] According to a DRDO report on Indian defense technology, "multi-directionally reinforced carbon-fiber preform structures form the potential backbones for high-performance advanced composites in polymeric, ceramic, and metal matrices. The technology can be used to control the thermal, mechanical, and physical properties of the composites by appropriate design parameters such as fiber orientation, fiber volume fraction, and fiber spacing. Such [MRCP technology] in different shapes such as blocks, cylinders, cones, and other near-net shapes exhibit superior structural integrity and produce highly engineered structural composites. They also exhibit a high-degree of damage tolerance and improved inter-laminar shear strength...these composites can continue to carry load even after noticeable fractures...the [MRCP] technology...has been successfully applied to missile re-entry nose-tips and rocket nozzles....the laboratory [DRDL] has developed the [MRCP] technology and developed the 3D and 4D performs for re-entry applications. It has also acquired expertise in design of weave configurations, the design and development of tooling and actual weaving process inspection and processing of multi-directionally reinforced performs. Matrix densification technology has been developed using a high-pressure impregnation, carbonization and a high-temperature graphitization process. The multi-directional reinforced carbon fiber preforms have been successfully densified to withstand re-entry conditions." — New Technology for Medium-Range Missile Developed in India, Xinhua News Agency (Beijing), 23 December 1989, in Lexis-Nexis Academic Universe, 23 December 1989, http://www.lexisnexis.com/; Dr. N.C. Birla and B.S. Murthy, eds., "Airframe Structures & Composite Components," Indian Defence Technology: Missile Systems (DRDO, Ministry of Defence, December 1998), pp.63-64.

[22] Referring to India's 22 May 1989 Agni-I test, Kalam reveals that India's indigenously developed re-entry vehicle technology was fully demonstrated when the nose-cone withstood temperatures of 3,000° Celsius. The four-directional pre-form used in the nose cone of the Agni was made of carbon-carbon material. The temperature in the Agni payload was 30° Celsius. Kalam also states that the Prithvi will enter production in 1992. [Note: The Agni's re-entry vehicle is designed to ensure that the temperature inside the vehicle does not exceed 60° Celsius, a condition necessary to protect the warhead and electronic systems placed inside. The re-entry vehicle consists of five sections. Each of these sections is made up of a two-layer composite construction. The inner layer is made up of carbon/epoxy filament mould constructed on a CNC winding machine. The inner layer is designed to bear structural loads. The outer layer is made up of carbon/phenolic filament wound construction, and cured in an autoclave at 7 bar pressure. The outer layer is designed to bear thermal loads. — "Our missile technology is most modern: Kalam," The Hindu (Chennai), 2 March 1991, p. 16; Dr. N.C. Birla and B.S. Murthy, eds., "Airframe Structures & Composite Components," Indian Defence Technology: Missile Systems (DRDO, Ministry of Defence, December 1998), pp.64-65.

[23] Raj Chengappa, Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power. (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000).

[24] http://www.globalsecurity.org/wmd/intro/bm-basics.htm "The heat generated during re-entry is not only dependent on atmospheric density, but is also inversely proportional to the square root of the radius of the RV's nose cone and proportional to the cube of its velocity. Hence, blunt nose RVs are heated less than slender ones; and lifting RV designs, which use the glider principle, produce less heat than ballistic hyperbolic descent designs because their velocity is typically lower. Thus, a full evaluation of thermal impacts during re-entry is dependent on both vehicle- and mission-specific criteria."

[25] 'ASL: From long-range missiles to lightweight callipers' M. Somasekhar  Business Line, THE HINDU  Jul 25, 2005. http://www.thehindubusinessline.com/2005/07/25/stories/2005072501331400.htm   Quote: "Recounting the exciting story of Agni for Business Line, Mr Agarwal said it was in 1987, encouraged by Mr Kalam, that he made a technical proposal on re-entry technology, which was the precursor for the technology demonstrator project for Long Range Systems as part of the ongoing IGMDP. The initial design was for a payload of 100-250 kg, at speeds of 7-8 km/sec. After some serious thinking, reviews and debates, Mr Kalam (who was a pioneer for higher payloads) pushed up the capability for the technology demonstrator. The first successful test flight took place on May 22, 1989, when Rajiv Gandhi was the Prime Minister. "It was a textbook flight," Mr Agarwal said. However, Mr Agarwal recalls, the success was preceded by a nerve-racking 45-day period, during which on two occasions, the flight test had to be cancelled. On April 1, 1989, the first attempt was to be made. At the last minute a hole in the launch was detected and the team returned. On May 1 again another technical snag was found and the scientists turned back. The success proved two milestones — it established the country's capability in re-entry technology; secondly the carbon composites, which were developed for the re-entry shield, meant lower weight of the missile and the utility of the carbon composite material."

[26] ICBM reach very high final velocity ranging from 7-8Km/sec. At 8Km/sec final velocity the rocket is capable of placing the payload in low earth orbit thus capable of staying in orbit for many weeks before re-entering atmosphere.

[27] NTI-Missile Chronology 1992: "...the propellant is of star configuration with a loading density of 78%." http://www.nti.org/e_research/profiles/India/Missile/1931_2023.html

[28] NTI-Missile Chronology 1992: "...the propellant is of star configuration with a loading density of 78%." http://www.nti.org/e_research/profiles/India/Missile/1931_2023.html

[29] NTI-Missile Chronology 1992: http://www.nti.org/e_research/profiles/India/Missile/1931_2023.html

[30] A. Subhananda Rao, "Development of Solid Propulsion Systems for Guided Missiles," in H.S. Mukunda and A.V. Krishnamurty, eds., Recent Advances in Aerospace Sciences and Engineering (Bangalore: Interline Publishing, 1992), pp.184-186.

[31] Propulsion System Status and Development Pathways In the Indian Context. 6th International Symposium, Propulsion for Space Transportation of the XXIst Century, Versailles, May 14 - 17, 2002.

[32] Although the rocket stage diameter is 1.0 meter, the ullage & retro rocket for stage separation adds to the missile diameter and thus increases to 1.3 meters.

[33] School of Mechanical & Aerospace Engineering Seoul National University. http://rpl.snu.ac.kr/databank/india/india.html

[34 India takes Big Technological Leap with Agni-II test. Deccan Herald: 12 April 1999. The missile is fitted with fins on the re-entry vehicle to facilitate manoeuvres. See Also: M. Singh, "Agni-II adds firepower to nuclear deterrence," Indian Express: 12 April 1999. "The presence of GPS has been reported but is not confirmed."

[35] DRDO told to test upgraded Agni in August. Deccan Chronicle: 15 July 1998.

[36] Technical Tune to Agni Test before Talks. The Telegraph: 30 August 2004. "The sources said it was a contained test fire. This probably means that the Agni-II was not flown for the full range it was designed for and its trajectory was altered to simulate the distance. A series of telemetry stations on the ground and on a naval vessel at sea tracked its flight. Earlier tests were said to have checked the missile's re-entry control and guidance technology, the sources said. It takes the Agni about 12 minutes to travel its full range with a conventional payload." http://www.telegraphindia.com/1040830/asp/nation/story_3694401.asp

[37]Technical Tune to Agni Test before Talks. The Telegraph: 30 August 2004. "The range of the solid-propellant Agni-II intermediate range ballistic missile can be varied according to payload and trajectory. The objective of today's test would be to reduce the circular error of probability for the longer-range variant, meaning that the missile was probably carrying a reduced payload." http://www.telegraphindia.com/1040830/asp/nation/story_3694401.asp

[38] Road Mobile Launcher for Agni-II: http://www.drdo.com/pub/techfocus/aug04/missile16.htm

[39] Technical Tune to Agni Test before Talks. The Telegraph: 30 August 2004. "According to one estimate, it costs between Rs.25 crore and Rs.35 crore to produce the missile." http://www.telegraphindia.com/1040830/asp/nation/story_3694401.asp

[40] Evaluating India's land-based Missile Deterrent. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[41] The then principal scientific advisor to the Indian government, Dr. Abdul Kalam, said that the Agni-II is designed to carry a nuclear warhead; he also stated that the May 1998 nuclear tests included a test of an Agni Class payload — Rahul Bedi, "Agni-II IRBM: Built to Carry Nuclear Warhead," JDW, Vol. 31, No. 17, 28 April 1999, p.7.

[42http://www.globalsecurity.org/wmd/intro/bm-basics.htm "A lifting re-entry vehicle has many operational advantages over a non-lifting vehicle. Primarily, the re-entry loads can be minimized to almost any desired level, with flexibility in landing site selection. The vehicle has the ability to deviate its re-entry trajectory to reach selected landing sites cross range from the orbital track, and to fine tune de-orbit propulsion system errors. Spherical and ballistic vehicles can only de-orbit to selected sites which are on the orbital ground track. A disadvantage of the lifting shape over the non-lifting shape lies in the complexity and high cost associated with guidance and control of the lifting vehicle. A failure of the guidance or control system could render the vehicle uncontrollable and cause it to diverge a great distance off course."

[43] Raj Chengappa, Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000). p.353. Picture titled 'Abdul Kalam in 1994 as scientific adviser explaining Agni's trajectory'

[44] The Indian Drive towards Weaponization. Federation of American Scientists (FAS). Quote: "Also, last minute/second adjustments have been optimized through on-board software which allow re-entry velocity trimming." http://www.fas.org/nuke/guide/india/missile/agni-improvements.htm

[45] Developing a delivery system R. RAMACHANDRAN Frontline Volume 16 - Issue 9, Apr. 24 - May. 07, 1999  "This is because the solid fuel is allowed to burn fully, which means that the velocity increment achieved before re-entry could be more or less from the mission perspective. Further, there is considerable dispersion in the burn time of solid fuels. Any compensation that is given to the missile during its ballistic phase (which happens once the second stage is fully burnt out) should be based on on-board sensor data and should be amenable to being adjusted reactively. These small force thrusters are liquid-fuel-driven and provide small increments in appropriate directions to shape the trajectory depending upon the target of the mission. It is these thrusters that give manoeuvrability during the re-entry phase. This has apparently been optimised through on-board software which, based on the initial trajectory fed in, does an appropriate "velocity trimming".

[46]  'Evaluating India's land-based Missile Deterrent'. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[47] The Defense Research & Development Organization (DRDO) reports that it may begin producing dry tuned gyros for missiles by the end of 1998. The dry tuned gyro after "detailed test evaluation, modeling, and S/W compensation" is expected to give "0.1 deg/hr, 200ppm class performance." The design of a "fiber optic gyro...of open loop design is under progress," and a "close loop integrated optics version is likely to come to the laboratory model stage by the year 2000. A ring laser gyro of 0.1 deg/hr (1s) class is planned to be produced by 2000...with the participation of an academic institution where the first pre-production model has been developed and tested..." — Dr. N.C. Birla and B.S. Murthy, eds., "Inertial Guidance and Sensors," Indian Defence Technology: Missile Systems, (DRDO, Ministry of Defence, December 1998), pp.157-158.

[48]http://www.bharat-rakshak.com/MISSILES/Agni-II.html

[49] 'Evaluating India's land-based Missile Deterrent', Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[50] Agni-III tests likely this year: Atre. Rediff, 23 March 2004. http://www.rediff.com/news/2004/mar/23agni.htm

[51] "The Agni-II incorporates a far more accurate terminal navigation and guidance system which constantly updates information about the missile flight path using Global Positioning System (GPS) information provided by ground-based beacons." Federation of American Scientists (FAS): The Indian Drive towards Weaponization. http://www.fas.org/nuke/guide/india/missile/agni-improvements.htm

[52] Agni-III tests likely this year: Atre. Rediff, 23 March 2004. http://www.rediff.com/news/2004/mar/23agni.htm

[53] DRDO's Chief Controller of R&D (Missiles), Dr A S Pillai, stated after the Agni-II test, "We have improved accuracy by a factor of at least three. It is a far more lethal missile now." He also said that the missile would have a unique on-board energy management system and an on-flight guidance process using navigational sensor technology.

[54] From theory of small error the error scaling is because:

A) IRBM velocity is 2.5 times smaller than GTO flight.

B) IRBM's ballistic flight is in earth's gravity (1 to 0.6G), while GSLV experiences it only 25% of it powered flight and thus very sensitive to propulsion error.

C) INS error is primarily dependent on velocity increment and flight time. Overall vehicle error is also dependent on operating gravity regime.

D) Flight time to apogee that is 44 times smaller for IRBM compared to GTO launch vehicle.

[55] Current Science, Volume 85, No.5, 10 September 2003, Second developmental flight of Geo-synchronous Satellite Launch Vehicle.

[56] GSLV-D2 data from: Current Science, Volume 85, No.5, 10 September 2003, Second developmental flight of Geo-synchronous Satellite Launch Vehicle.
.......GSLV-F01 data from: ISRO – GSLV-F01 Launch Successful – Places EDUSAT in Orbit. http://isro.org/newsletters/spaceindia/julsep2004/GSLV%20FO1.htm

[57]  Ibid.

[58] EDUSAT placed in orbit. T S Subramanian, The Hindu, 21 September 2004.

ISRO: GSLV-F01 Launch Successful – Places EDUSAT in Orbit – http://isro.org/newsletters/spaceindia/julsep2004/GSLV%20FO1.htm

Parameter Specification GSLV-D2
Actual (Dispersion)
GSLV-F01
Actual (Dispersion)
. .
Perigee (km) 180.5, ±5 (2.8%) 180.2 (0.17%) 181.5 (0.55%)
. .
Apogee (km) 35,975 ± 675 (1.9%) 36,045.7 (0.19%) 35,988 (0.036%)
. .
Inclination (degree) 19.3 ± 0.1 19.25 (0.26%) 19.29 (0.052%)

[59] Raj Chengappa, Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000). p.353. Picture titled 'Abdul Kalam in 1994 as scientific adviser explaining Agni's trajectory'.

[60] Evaluating India's land-based Missile Deterrent. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[61] Indian space launchers also use Strap-down INS and have consistently inserted payload in accurate orbit.

[62] Evaluating India's land-based Missile Deterrent. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[63] The impact of 180kg liquid fuel or in the form of solid fuel cartridges have the similar effect on missile range.

[64http://www.bharat-rakshak.com/MISSILES/Agni-II.html "While a new and longer-range system can certainly be developed if the Services require it, the present configuration is in operational mode," says Dr. Kalam. Range, he adds, could be optimised by appropriately configuring the payload mass.

[65Evaluating India's land-based Missile Deterrent. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[66] 'Technical Tune to Agni Test before Talks'. The Telegraph: 30 August 2004. "The range of the solid-propellant Agni II intermediate range ballistic missile can be varied according to payload and trajectory. The objective of today's test would be to reduce the circular error of probability for the longer-range variant, meaning that the missile was probably carrying a reduced payload." http://www.telegraphindia.com/1040830/asp/nation/story_3694401.asp

[67] 'Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power',Raj Chengappa. (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000), pp.435-436.

[68] LAUNCHING  PLATFORMS FOR AGNI VARIANTS, DRDO. http://www.drdo.com/pub/techfocus/aug04/missile16.htm

[69] 'Propulsion System Status and Development Pathways In the Indian Context'. 6th International Symposium, Propulsion for Space Transportation of the XXIst Century, Versailles, May 14 - 17, 2002.

[70] ISP is based on ASLV-1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[71] ISP is based on ASLV-2 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS3 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[72] Assumes the HAM engine is like Indian LAM or R40A with N2O4/MMH fuel (10 kg engine weight). ISP (Vac) of 306 thrust of 394 Kgf.

[73] School of Mechanical & Aerospace Engineering Seoul National University. http://rpl.snu.ac.kr/databank/india/india.html

[74] June 1999: India's external affairs and defense ministers, Jaswant Singh and George Fernandes, discuss the need for a ballistic missile to cover the gap between the short-range Prithvi and the longer-range variants of the Agni ballistic missile. — K. Santhanam, "Agni-I: A short-range N-missile India urgently needs," Times of India (Mumbai), 27 January 2002, http://www.timesofindia.com/, in FBIS Document SAP20020127000025, 27 January 2002.

[75] October 1999: The Indian government approves the development of an 800 - 900 km range, road mobile, solid-propellant variant of the Agni ballistic missile. The development and first flight-test of the shorter-range variant of the Agni is expected within 15 months. — K. Santhanam, "Agni-I: A short-range N-missile India urgently needs," Times of India (Mumbai), 27 January 2002, http://www.timesofindia.com/, in FBIS Document SAP20020127000025, 27 January 2002.

[76]  A good overview of the Agni-I is provided at: http://www.bharat-rakshak.com/MISSILES/Agni-I.html

[77] Army's missile group to maintain Agni A-1. The Hindu, 05 July 2004. http://www.hinduonnet.com/

[78] Propulsion System Status and Development Pathways In the Indian Context. 6th International Symposium, Propulsion for Space Transportation of the XXIst Century, Versailles, May 14 - 17, 2002.

[79] ISP is based on ASLV-1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[80] Assumes the HAM engine is like Indian LAM or R40A with N2O4/MMH fuel (10 kg engine weight). ISP (Vac) of 306 thrust of 394 Kgf.

[81] School of Mechanical & Aerospace Engineering Seoul National University. http://rpl.snu.ac.kr/databank/india/india.html

[82] 'Long-range Agni missile gets go-ahead', Times Of India (New Delhi), 01 June 2001. Quote: "India's Defense Minister Jaswant Singh informs the parliament's Consultative Committee on Defense, that the Agni ballistic missile is likely to be inducted into the armed forces in 2001-2002. Singh tells members of parliament that limited production of the operational missile system has commenced and the missile forms the bedrock of India's minimum deterrent. According to Singh, "No constraints in funds will be allowed to come in the way of the indigenous development of the integrated missile program" and the development of the Agni-II is proof of the country's determination to indigenize defense production. Indian defense sources claim that the government is also considering approving the development of missiles with a longer range than the Agni-II."

   'India to fine-tune n-delivery systems', The Hindu, Friday, June 01, 2001
India today said it would fine-tune its nuclear delivery systems and cited China's larger arsenal as well as its help to Pakistan for developing atomic weapons.  http://www.hinduonnet.com/2001/06/01/stories/01010005.htm

[83] 'Agni missile will travel lighter soon', PTI [ THURSDAY, OCTOBER 13, 2005 12:45:45 PM] Economic Times. " Agni, with a power plant made of composite materials that would considerably reduce the weight of this IRBM class missile". "Agni is an intermediate range ballistic missile with two solid fuel stages and a Post Boost Vehicle integrated into the missile's Re-entry Vehicle, which is made of a light-weight carbon-carbon composite material able to sustain high thermal stresses."   http://economictimes.indiatimes.com/articleshow/1261173.cms

  ,

[84] Pokharan-II test resulted in a lighter weapon payload, whereas the original RV was intended for a much heavier boosted fission weapon. In view of rapid developments however, the basic design earlier developed continued to be used and keeping the future option open, for more optimized and lighter payloads.

[85] Sify News, 08 August 2003: India develops world's first re-entry heat shield.

[86] Composites: Use in saucepan handles, artificial limbs and the AGNI CURRENT SCIENCE, VOL. 86, NO. 3, 10 FEBRUARY 2004  Advanced Systems Laboratory (ASL), Hyderabad: "The front-end technologies being developed include ultra high temperature composites, high performance composite rocket motor casings, radome for missiles and aircrafts, all-carbon re-entry vehicle structures, carbon composite canister technology, thrust vectoring through flex nozzles for large rocket motors, solid propulsion, control systems, system integration and explicit energy management guidance systems." http://www.ias.ac.in/currsci/feb102004/372.pdf 

[87] Sify News, 08 August 2003: 'India develops world's first re-entry heat shield'.

[88] Technical Tune to Agni Test before Talks. The Telegraph: 30 August 2004. "The range of the solid-propellant Agni-II intermediate range ballistic missile can be varied according to payload and trajectory. The objective of today's test would be to reduce the circular error of probability for the longer-range variant, meaning that the missile was probably carrying a reduced payload." http://www.telegraphindia.com/1040830/asp/nation/story_3694401.asp

[89] Deccan Herald, 20 Dec 2005. "Indo-Russian tie-up on Glonass satellite system". http://www.deccanherald.com/deccanherald/dec202005/state1861820051219.asp

[90] 'Indian Regional Navigation Satellite System approved', 9/5/2006   http://www.india-defence.com/reports/1894

[91] Sify News, 08 August 2003: 'India develops world's first re-entry heat shield'. Quote: "...developed and successfully flight-tested the unique all carbon composite re-entry heat shield with multi directional carbon re-entry nose tip and control surfaces in the Agni systems."

[92] Defence scientists embark on making 'smart' missiles. The Hindu Businessline, 02 October 2004.
http://www.thehindubusinessline.com/2004/10/03/stories/2004100301340500.htm

[92.A]Review panel studying Agni III failure: scientific adviser, The HINDU Date:10/11/2006 http://www.thehindu.com/2006/11/10/stories/2006111015800700.htm "The first rocket motor case of the improved design, of maraging steel and with 1.2 metre diameter, for the Agni programme was handed over to the M. Natarajan, scientific advisor to the Defence Minister by the Ramakrishna Engineering Company."  

[93] Sify News, 08 August 2003: India develops world's first re-entry heat shield. Quote: "The carbon composite motor casings are some of the inputs to enhance the performance of long-range systems."

[94] Composites: Use in saucepan handles, artificial limbs and the Agni missile. Current Science, Vol.86, No.3, 10 February 2004. Advanced Systems Laboratory (ASL), Hyderabad. "The front-end technologies being developed include ultra high temperature composites, high performance composite rocket motor casings, radome for missiles and aircrafts, all-carbon re-entry vehicle structure, carbon composite canister technology, thrust vectoring through flex nozzles for large rocket motors, solid propulsion, control systems, system integration and explicit energy management guidance systems".  "The carbon composite motor casings are some of the inputs to enhance the performance of long-range systems." http://www.ias.ac.in/currsci/feb102004/372.pdf

[95] Author's Note: "Mass-fraction comparable to filament wound stage of similar rocket stages."

[96] Propulsion System Status and Development Pathways In the Indian Context. 6th International Symposium, Propulsion for Space Transportation of the XXIst Century, Versailles, May 14 - 17, 2002.

[97]  ISP is based on ASLV-1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[98]ISP is based on ASLV-2 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS3 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[99]  Assumes the HAM engine is like Indian LAM or R40A with N2O4/MMH fuel (10 kg engine weight). ISP (Vac) of 306 thrust of 394 Kgf.

[100] School of Mechanical & Aerospace Engineering Seoul National University. http://rpl.snu.ac.kr/databank/india/india.html

[101] Agni 3 test launch likely by year end, Deccan Herald July 04,2005  http://www.deccanherald.com/deccanherald/jul42005/national15738200573.asp

'India ready to test fire advanced 3000 Km Agni III missile in the next six months – hypersonic missiles getting developed' Indiadaily May 17, 2005 IndiaDaily - India ready to test fire advanced 3000 Km Agni III missile in the next six months – hypersonic missiles getting

Also "India will test-fire longest range missile: Natrajan"  NEW DELHI, MAY 17 2005 (PTI) outlookindia.com

Also "India's Agni III will span 3,000 km" PTI. Times Of India, MAY 17, 2005 

Agni-III ready to go, DRDO awaits govt nod EXPRESS NEWS SERVICE May 15, 2006 

Agni-III can lift off in 2-3 weeks

Agni-III ballistic missile ready for launch Indo-Asian News Service New Delhi, HindustanTimes.com February 3, 2006 Agni-III ballistic missile ready for launch HindustanTimes.com

India Readies for Agni III Launch, Agni III ready for tests, although schedule still in flux, Neelam Mathews, Aviation Week & Space Technology, 02/13/2006, page 48 India Readies for Agni III Launch

Agni III ready for launch: DRDO NEW DELHI, FEB 3 (PTI) outlookindia.com wired

Agni-III missile to be test-fired by year-end. The Hindu, 30 March 2005. http://www.hindu.com/2005/03/30/stories/2005033011851200.htm

[102Agni-III flight unsuccessful. The Hindu, Monday, Jul 10, 2006 http://www.hindu.com/2006/07/10/stories/2006071007510100.htm

[103`India has tech to go beyond Agni-III', Our Bureau, Hyderabad  The Hindu 

Business Line, May 20, 2005. http://www.blonnet.com/2005/05/20/stories/2005052002820300.htm    "INDIA has the technological capability to build long-range missiles beyond Agni-III, whose first test flight is slated for the end of 2005, according to Dr Ram Narain Agarwal, Programme Director of Agni and Director of the Hyderabad-based Advanced Systems Laboratory (ASL). Agni-III, the long-range surface-to-surface missile, is targeted to have a range of 3,000-3,500 km. It would have a total of three test flights, including one with the user. It can carry a payload (warhead both conventional and nuclear) of 1-1.2 tonnes."

Agni-III to be inducted by 2008'- The Times of India, JUNE 26, 2005'  

[104Although some news report state 1.8meter diameter, the stage diameter is more likely to be 2meter. 

[105] Agni-III to be test fired by year-end. Deccan Chronicle, 30 March 2005 . "…capacity to carry conventional as well as nuclear warheads of over 1,500 kg." 

[106 "Agni-III raring to go, Govt not keen" Vishal Thapar, CNN-IBN May 15, 2006  "DOUSING THE AGNI: Govt has been delaying the test-fire of Agni-III missile for the past two years."  url: http://www.ibnlive.com/article.php?id=10452&section_id=3 Image Location: http://www.ibnlive.com/pix/sitepix/agni248.jpg Video Location: http://static.ibnlive.com/data/videos/agni_3.wmv

[107] Due to historical reasons the Agni-II used the 1980 vintage RV designed to accommodate a large boosted fission nuclear weapon of 200Kt yield weighing 1000 Kg (at that time BARC had not yet developed 2 stage Thermonuclear weapon and the high yield weapon was a boosted fission weapon ). 

[108] This new RV-Mk4 design used on Agni-III was developed after 1998 nuclear test that validated the new and lighter 200-300 Kt thermonuclear weapon of 1995 vintage. Thus this RV does use fins, is nose is slightly sharper, shorter and its interface blends with the larger diameter payload adapter. 

[109India Cancels Agni III Test, UPI-Washington, May 31, 2006 , “The Agni III is said to be able to deliver a 440-pound to 550-pound warhead with a high degree of accuracy.” http://www.spacewar.com/reports/India_Cancels_Agni_III_Test.html

[110] The ballistic coefficient β is a measurement of an object's ability to move through a fluid. It takes into account the effects of an object's density and its skin friction, and is expressed as:

         β = m * CD / A        where   m: mass,  CD: coefficient of drag,  A: area.  

[111] This was an issue with the earlier RV Mk-2 design. The older Mk-2 with its blunt nose is an all range RV, however for lighter payload its β is relatively low, thus slowing down the RV at the fag end of its trajectory. 

[112] India develops world' first re-entry heat shielAug 08, 2003 Sify News

"India has, for the first time in the world, developed and successfully flight-tested the unique all carbon composite re-entry heat shield with multi directional carbon re-entry nose tip and control surfaces in the Agni systems. The carbon composite motor casings are some of the inputs to enhance the performance of long-range systems. There has been a marked improvement in composite process technologies for the Agni variants. The technological challenges posed by the Missile Technology Control Regime in materials, process technologies and equipment were surmounted with indigenous technology initiative.... .... The aerospace systems already developed in the country have composites made of highly advanced technologies and further advancements in composite products for use in high speed and high temperature environment upto 6000 degree Celsius."

[113] ibid

[114] Composites: Use in saucepan handles, artificial limbs and the AGNI, CURRENT SCIENCE, VOL. 86, NO. 3, 10 FEBRUARY 2004 http://www.ias.ac.in/currsci/feb102004/372.pdf "India has developed propulsion and re-entry systems of aerospace vehicles that need to operate in high temperature regimes such as 3000–5000°C and meet the aero thermal environment of re-entry".

'Agni-III launch likely next year', T.S. Subramanian, The Hindu,  Nov 30, 2005  "The ASL has pioneered several missile technologies including a heat shield made of carbon composite without any metal back-up for missile payloads, large-sized rocket motor casings, larger nozzles, separation systems for the missile stages and pyrotechnical devices".

A young achiever T.S. SUBRAMANIAN, Frontline Volume 22 - Issue 20, Sep. 24 - Oct. 07, 2005 "Metal made the heat shield heavy, so the weaving and winding of the carbon- fibre around the shield was a demanding but necessary task to lighten it, Agarwal said. Carbon-composites are not only crucial in the fabrication of the Agni heat shield but they also cover a part of the body of Tejas, India's Light Combat Aircraft, and brake discs in fighter planes and light-weight callipers for polio-affected children."

[115] A success story T.S. SUBRAMANIAN Frontline Volume 22 - Issue 20, Sep. 24 - Oct. 07, 2005. http://www.hinduonnet.com/fline/fl2220/stories/20051007002009200.htm "The four-year-old Advanced System Laboratory in Hyderabad has contributed immensely to the success of India's missile development programme, which has reached the intercontinental ballistic missile stage. ... The ASL has already achieved a breakthrough by developing a heat-shield made of carbon composite without any metal back-up. (The heat-shield protects the warhead and avionics from the high temperatures generated by the missile's re-entry into the earth's atmosphere.) "We were the first one to do the carbon composite heat-shield without any metal back-up. It has been designed, developed and flight-tested for Agni, and it is perhaps the first heat-shield of its kind in the world," Agarwal said."

[115A] Composites: Use in saucepan handles, artificial limbs and the AGNI CURRENT SCIENCE, VOL. 86, NO. 3, 10 FEBRUARY 2004  Advanced Systems Laboratory (ASL), Hyderabad: "... .. . Multiple Independently Targetted Re-entry Vehicle (MIRV) Reusable missions and MIRVs are future systems that would gain from carbon nanotubes, nanocarbon reinforced ceramics, smart structures and advanced materials. India has developed propulsion and re-entry systems of aerospace vehicles that need to operate in high temperature regimes such as 3000–5000°C and meet the aero thermal environment of re-entry Scientists have successfully flight-tested the unique all-carbon composite re-entry heat shield with multi-directional carbon–carbon re-entry nose tip and control surfaces in the AGNI missile systems. The carbon–carbon composite brake discs developed for the LCA have undergone flight tests." http://www.ias.ac.in/currsci/feb102004/372.pdf 

[116]  Launching platforms for Project K-15. http://www.drdo.com/pub/techfocus/aug04/missile13.htm

[117] Agni-III maiden flight failure was primarily due to first stage failure. There are strong indications that design deficiency in the way flex nozzle stage was used in low altitude application was one of the contributing cause. 

[118] Estimated.

[119] Estimated.

[120Estimated.

[121] Estimated.

[122] Estimated.

[123] ISP is based on ASLV-1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS1 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[124] ISP is based on ASLV-2 information at http://www.bharat-rakshak.com/SPACE/space-launchers-slv.html and PSLV-PS3 information at http://www.bharat-rakshak.com/SPACE/space-launchers-pslv.html

[125] Estimated.

[126] Estimated.

[127] Slight possibility that it could turn out to be 2.0 meter diameter 

[128] Slight possibility that it could turn out to be 2.0 meter diameter 

[129] Estimated.

[130] Estimated.

[131] "Indo-Russian tie-up on Glonass satellite system" Deccan Herald, 20 Dec 2005 . http://www.deccanherald.com/deccanherald/dec202005/state1861820051219.asp  

[132] "Indian Regional Navigation Satellite System approved", 9/5/2006 http://www.india-defence.com/reports/1894

[133] "SATNAV Industry Meet Held at ISRO Satellite Centre",  July 4, 2006, The Government has also approved a project recently to implement an Indian Regional Navigation system (IRNSS) over India in the next 5-6 years. It will consist of a constellation of 7 satellites and a large ground segment. The entire IRNSS system will be under Indian control. The space segment, ground segment and user receivers will be built in India.  http://www.isro.org/pressrelease/Jul04_2006.htm

[134Centre gives new life to Agni-III,Rahul Datta | New Delhi, Daily Pioneer. July 14, 2006 The DRDO also briefed the Minister about the plausible cause of the snag and assured him that they would be able to rectify the snags for the forthcoming launches. The tests would be two-stage even as the DRDO was ready with a three-stage missile test, sources said. www.dailypioneer.com

BOOST TO INDIAN ARMED FORCES’ DETERRENCE ARSENAL, India to develop intercontinental ballistic missile - Deccan Herald - Internet Edition India will soon develop an intercontinental ballistic missile (ICBM) with a flight range of 9,000-12,000 km. According to sources in the ministry of defence (MoD), based on the experience with the Agni, the medium range ballistic missile (MRBM), the MoD is pressing for the creation of an ICBM. The ICBM would probably be a three-stage ballistic missile"  http://www.deccanherald.com/deccanherald/aug252005/index2032552005824.asp

[134A] Composites: Use in saucepan handles, artificial limbs and the AGNI CURRENT SCIENCE, VOL. 86, NO. 3, 10 FEBRUARY 2004  Advanced Systems Laboratory (ASL), Hyderabad: "... .. . Multiple Independently Targetted Re-entry Vehicle (MIRV) Reusable missions and MIRVs are future systems that would gain from carbon nanotubes, nanocarbon reinforced ceramics, smart structures and advanced materials. India has developed propulsion and re-entry systems of aerospace vehicles that need to operate in high temperature regimes such as 3000–5000°C and meet the aero thermal environment of re-entry Scientists have successfully flight-tested the unique all-carbon composite re-entry heat shield with multi-directional carbon–carbon re-entry nose tip and control surfaces in the AGNI missile systems. The carbon–carbon composite brake discs developed for the LCA have undergone flight tests." http://www.ias.ac.in/currsci/feb102004/372.pdf 

[135]  Tritium breakthrough brings India closer to an H-Bomb arsenal. "How tritium extracted from CANDU-type power reactors supports India's H-Bomb capability." Jane's Intelligence Review, January 1998. http://www.ccnr.org/india_tritium.html

[136] It is not clear if the Pokhran-II (PoK-II) thermo-nuclear test used U235 spark-plugs in the secondary stage core. The PoK-II test was not configured with active mantle for the tertiary fission stage.

[137] Legend: 'WpnGrd'- Weapon Grade;  'RctrGrd'- Reactor Grade.

[138] Technological, Scientific Success. T S Subramanian. Frontline, Vol.15, No.11, May 23 - Jun 05, 1998. Quote: "The fission device was similar to the one tested on May 18, 1974 at Pokhran but had a new design. It was smaller in size and weight, but its yield was higher - 15 kilotonnes, compared with 12 kilotonnes in 1974."
http://www.frontlineonnet.com/fl1511/15110130.htm

[139] India's silent bomb. Bulletin of the Atomic Scientists. Quote: "India is also moving toward realization of large-scale use of uranium 233 as fuel for its power reactors. Uranium 233 is a fissile isotope of uranium that requires about as much material per bomb as plutonium. Uranium 233 is made by irradiating natural, non-radioactive thorium in a reactor, and India attaches a high priority to the development of thorium/uranium 233 fuel for its power reactors. Irradiation of thorium in the Cirus, Dhruva, and the MAPS reactors has resulted in the production of kilogram quantities of uranium 233." http://www.thebulletin.org/article.php?art_ofn=sep92albright

[140] Legend: WpnGrd- Weapon Grade. RctrGrd- Reactor Grade.

[141] Institute of Peace and Conflict Studies: http://www.ipcs.org/ipcs/ipcsSeminars2.jsp?action=showView&kValue=415

[142] Perkovich, India's Nuclear Bomb, p.242

[143] 'Evaluating India's land-based Missile Deterrent'. Indian Defense Review Vol-19(4) Oct-Dec 2004, ISSN 0970-2512, Arun Vishwakarma, Dr Sanjay Badri Maharaj. Lancer Publishers & Distributors, New Delhi.

[144] Government to hand over Agni missiles to Army. Press Trust of India, New Delhi, 23 September 2003.

[145] Series of Agni-III tests likely: Aatre. Press Trust of India, New Delhi, 23 March 2004.

[146] India To Develop Extensive Nuclear Missile Arsenal. Vivek Raghuvanshi, Defense News, 24 May 1999, p.14. Quote: "Defense Research & Development Organization (DRDO) sources say that program to develop Surya is likely to cost $50 million and the missile will be ready for launch by mid-2001. An advanced version of the Surya will also be developed after the first missile is tested. In addition, twenty 2,000 km-range Agni ballistic missiles will be built at a cost of $150 million by the end of 2001."

[147] Agni's launch raises questions. Manoj Joshi, Times of India (Mumbai), 22 February 1994, p.8, in FBIS Document JPRS-TND-94-010, 05 May 1994, p.22. Quote: "Post-test analysis reveals that the failure was caused by the extension in the missile's length from 19 meters to 21 meters and an increase in its weight from 14 tons to 16 tons. The increased length and weight changed the vehicle's vibration characteristics. However, Indian scientists and engineers failed to anticipate the impact of these changes on the sensors' calculations. When the missile lifted off, the sensors mounted on the inner skin of the missile picked up the vibrations on its structure and erroneously started making course corrections, which caused the missile to break up under stress. The Times of India reports that the problem was identified and resolved with the help of a Russian consultant in 1993. However Indian scientists T.K. Ghosal (Jadavpur University, West Bengal) and V.G. Sekaran (Agni's vehicle director) dispute this report. The latter claim that Indian scientists identified the problem by subjecting a full-scale model to vibration tests. For future tests, Indian scientists decide to remove the sensors from the missile's inner casing to its bulkhead to prevent the possibility of structural vibrations affecting the sensors' calculations."

Raj Chengappa, "Caught in the Crosshairs," Weapons of Peace: The Secret Story of India's Quest to be a Nuclear Power (New Delhi: Harper Collins Publishers India Pvt. Ltd., 2000), pp.373-374.

[148] Report Says Agni Missile Test Met All Objectives, Doordarshan Television Network (New Delhi), 20 February 1994, in FBIS Document JPRS-TND-94-006, 16 March 1994, p.19. Quote: "India conducts third test of the Agni I. The missile is launched from the Interim Test Range (ITR) in Chandipur (Orissa) at 5:45 p.m. and impacts at a designated target off the Car Nicobar islands within 22 minutes at a distance of 1,400 km. The 21-meter, 19-ton missile uses a solid propellant in the first stage and a liquid propellant in the second stage. A brief issued by the Defense Research & Development Organization (DRDO) says that the third test validated the innovative design features aimed at testing the missile's longer-range and advanced maneuverability during the re-entry phase. Scientists tested a new re-entry vehicle with fins, which allows it to manoeuvre for greater accuracy. The test also validated a more advanced stage separation process. An Indian defense ministry press release says that the Agni payload performed to the design specifications with great accuracy."

Agni's launch raises questions. Manoj Joshi, Times of India (Mumbai), 22 February 1994, p.8, in FBIS Document JPRS-TND-94-010, 05 May 1994, p.22.

Third Agni test launch fulfils 'set objectives'. Jane's Defence Weekly (Coulsdon, Surrey), 05 March 1994, p.18

Countdown starts for India's ballistic missile. Rahul Bedi, Jane's Defence Weekly (Coulsdon, Surrey), 11 September 1996, p.21.

[149] 'Over 2,000 km range Agni-II successfully test fired'. Times of India (New Delhi), 12 April 1999. Quote: "India tests the Agni-II missile from a new launch facility at the LC-4 on Wheeler's Island. The new facility has been built to bypass the problem of evacuating villagers from the Interim Test Range's (ITR) surrounding areas every time a missile is tested. This is the fourth test in the Agni program. The 20 meter-high missile was launched from a rail-mobile platform at 9:47 a.m. and reaches the point of impact in 11 minutes. Defense Minister George Fernandes says that, "We [India] have reached the point of operationalization of Agni-II as a weapon system." The salient features of this test are demonstration of mobile launch capability; an all solid-solid propulsion system; range of over 2,000 km; improved guidance and navigation system; and an advanced communication interface. According to Defense Research & Development Organization (DRDO) sources, the Agni II is equipped with a global positioning system (GPS); satellite inputs during the missile's flight time help an on-board computer to correct for navigational errors and improve accuracy. Unlike the earlier models, which used a liquid configuration in the second stage, the Agni-II has an all solid-fuel configuration. The Agni's designers and engineers say that the missile is highly mobile and can be transported by rail or road anywhere within India. When compared to the Agni-I, which required half a day of preparation for launch, the Agni-II can be launched within 15 minutes. The Agni-II also incorporates a terminal navigation and guidance system; the missile uses ground-based beacons to correct for deviations in the missile's path even as it travels at hypersonic speeds of over Mach 14. According to DRDO's chief controller of R&D (missiles), the Agni's accuracy has been "improved by a factor of three." Indian nuclear and missile scientists also test an actual nuclear warhead assembly without its plutonium core during the test. In an earlier static test involving a dummy warhead, severe vibrations had caused it to trigger prematurely due to a high-arching voltage problem. Flight telemetry data from the Agni's test shows that the dummy warhead's safety locks unlocked in a predetermined manner."

Agni-II Adds Fire Power to N-Deterrence. Manvendra Singh, Indian Express (Bombay), 12 April 1999.

Duncan Lennox, ed., Jane's Strategic Weapons Systems, Issue 32, (Coulsdon, Surrey), 2000, p.73

Agni-II joins nation's missile showcase, Hindustan Times (New Delhi), 11 April 1999.

Boom for Boom. Raj Chengappa, India Today (New Delhi), 26 April 1999.

[150] Agni–II test fired. Press Indian Bureau, 29 August 2004. The flight was witnessed by Defence Minister Shri Pranab Mukherjee, Defence Secretary Shri Ajai Vikram Singh, Secretary DRDO, Dr V K Aatre, C-in-C Strategic Forces Command Air Marshal Ajit Bhavnani, Mission Director of Agni Shri R N Agarwal and other senior Civil and Military Officials.

Deccan Herald, 30 Aug 2004: Defence Minister Pranab Mukherjee, the Scientific Adviser to the Defence Ministry, Dr V K Atre, the Project Director of the Agni series of missiles, Mr R N Agarwal, along with over 100 scientists were present at the launch complex. This is the third test of Agni-II.

Silicon India, 30 Aug 2004: India tests nuclear-capable Agni missile.

Rediff, 29 August 2004: India tests Agni-II missile.

The Telegraph, Calcutta, 01 September 2004: Agni test checks nuke-war power.


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