India’s Missiles – With a Little Help from Our Friends

Bulletin of the Atomic Scientists
November 1989, pp. 31-35

Last May 22, India became the first country to test a strategic missile derived from a civilian space program. The missile’s first-stage rocket motor, heat shield, and guidance system all came from India’s space effort — generously launched and sustained by foreign help.

Prime Minister Rajiv Gandhi claimed that the missile, called “Agni” (fire), is “an R&D vehicle, not a weapons system.” Then he qualified the assertion. “Agni is not a nuclear weapons system,” he said. “What Agni does is to afford us the option of developing the ability to deliver non-nuclear weapons with high precision at long ranges.”

In the May test, the missile reportedly flew 625 miles. But it is designed to carry a one-ton payload 1,500 miles, far enough to hit cities in southern China. Carrying a half-ton atomic bomb, the Agni would be able to fly about 2,200 miles, far enough to hit Beijing.

Whether Agni eventually carries nuclear or conventional weapons, the missile should destroy any illusions about sharing technology in the interest of peaceful uses of outer space. The story of the Agni’s development shows how difficult it is to separate civilian and military uses of technology, and just how futile may be the recent, belated attempts to control the proliferation of military missile technology. A control regime established by seven Western nations in 1987 seeks to prevent precisely this sort of development. [See the June 1988 Bulletin.] Yet the regime has no provisions for enforcement, and the Indian program continued full speed ahead, with some foreign – particularly West German – cooperation, after the regime was adopted.

Lessons in America

Agni’s foreign ancestry dates from the 1960s. In November 1963, the United States began India’s space program by launching a U.S. sounding rocket from Indian soil. (Sounding rockets fly straight up into the atmosphere to conduct scientific experiments. They are too small to launch satellites.) The United States was followed by others. Between 1963 and 1975, more than 350 U.S., French, Soviet, and British sounding rockets were launched from India’s Thumba Range,[1] which the United States helped design. Thumba’s first group of Indian engineers had learned rocket launching and range operation in the United States.

Among them was the Agni’s chief designer, A. J. P. Abdul Kalam. In 1963-64, he spent four months in training in the United States. He visited NASA’s Langley Research Center in Virginia, where the U.S. Scout rocket was conceived, and the Wallops Island Flight Center on the Virginia coast, where the Scout was being flown. The Scout was a low-cost, reliable satellite launcher that NASA had developed for orbiting small payloads.

Soon afterward, in 1965, the Indian government asked NASA how much it would cost and how long it would take to develop an Indian version of the Scout, and whether the United States would help. NASA replied that the Scout was “available . . . for purchase . . . in connection with scientific research,” but warned that “transfer of this technology . . . would be a matter for determination by the Department of State under Munitions Control.”[2] NASA nevertheless sent India technical reports on the Scout’s design, which was unclassified. India’s request should have raised some eyebrows: it came from Homi Bhabha, head of the Indian Atomic Energy Commission.

But Kalam had the information he needed. He returned to India and built the SLV-3 (Space Launch Vehicle), India’s first satellite launcher. Its design is virtually identical to the Scout’s. Both rockets are 23 meters long, use four similar solid-fuel stages and “open loop” guidance, and lift a 40-kilogram payload into low earth orbit. The SLV’s 30-foot first stage would later become the first stage of the Agni.

NASA officials say U.S. aid to India in rocketry was limited to the program in the 1960s. In 1988, however, the United States agreed to supply an advanced ring laser gyroscope to help guide a new Indian fighter plane.[3] It is not clear what will prevent India from using it to guide missiles. The highly accurate device is essentially solid state, making it easy to adapt to the demands of missile acceleration.

French lessons: liquid fuel

France also launched sounding rockets from India, and in the late 1960s allowed India to begin building “Centaure” sounding rockets under license from Sud Aviation. But France’s main contribution has been in the field of liquid propulsion. Under a license from France’s Societe Europeene de Propulsion (SEP), India is building its own version of the Viking high-thrust liquid rocket motor, used on the European Space Agency’s Ariane satellite launcher.[4] Indian engineers helped develop the Viking in the mid-1970s, then began a program of their own. India has now built an experimental model of the Viking engine, called the Vikas.

The training in liquid propulsion seems to have paid off. Just over a year before testing the Agni, Kalam tested a smaller predecessor, the “Prithvi” (earth), which uses a liquid-propelled motor to carry a one-ton payload 150 miles. It resembles the widely sold Soviet Scud-B. Indian sources say that the Agni’s second stage is a shortened version of the Prithvi.[5]

A German intensive tutorial

The aid of the United States and France, however, was quickly dwarfed by West German help in the 1970s and 1980s. Germany gave India help in three indispensable missile technologies: guidance, rocket testing, and the use of composite materials. All were supposed to be for the space program, but all were equally useful for military missiles.

The German government’s aerospace agency DLR (Deutsche Forschungsanstalt fur Luftfahrt und Raumfahrt e.V.) began tutoring India in rocket guidance in 1976.[6] The first step was to put a German interferometer on an Indian sounding rocket. An interferometer works by using antennas placed at different locations on the rocket to measure the phase of a radio signal received from the ground. The phase difference among the antennas reveals their relative positions on the rocket and thus the rocket’s attitude, which can be monitored and corrected from the ground. The first launch of an Indian rocket with a German interferometer was in 1978. By 1981 the project had been expanded to include an on-board DLR microprocessor. In April 1982, India tested its own version of the same interferometer.

The next step was to make a navigation system that did not depend on signals from the ground, one that could guide a payload through space by determining its position and speed at any moment. The “autonomous payload control system,” which India proposed in July 1981, would provide “full autonomous navigation capability to spaceborne sensors,” determining “position, velocity, attitude, and precision time in a real-time mode.” India would supply the rockets and satellites; Germany would provide the brains of the guidance system. The key component would be an on-board computer, using a microprocessor based on the Motorola family M 68000, and the software to run it.

It must be noted that an inertial navigation system that can guide satellites can also guide warheads. The United States used NASA’s experience in guiding the Titan II transtage, a “bus” designed for multiple satellite launchings, to develop a bus that would accurately deliver small nuclear warheads.[7]

The German-Indian plan was carried out. By January 1982, the two countries had agreed on a series of joint projects for the program. But at the same time, India announced that it was designing a new navigation system for its own space rockets: it would replace the “open loop” system used on its first launcher, the SLV-3, with a “closed loop” system for its Advanced Space Launch Vehicle and its Polar Space Launch Vehicle. An open loop system can only correct the rocket’s attitude, not deviations from the planned flight path. A closed loop system can correct both, because it senses and determines the rocket’s position in space. It amounts to an autonomous navigation system.

So while India’s program with Germany, called APC-Rex for Autonomous Payload Control Rocket Experiment, was developing autonomous navigation for a satellite, India would develop autonomous navigation for its own rockets. India would need a brain for its space rockets’ new closed loop system, which it would provide by developing the “Mark-II” onboard processor – “based on [the] Motorola 6800 microprocessor with 16-bit word length” – the same as that used in the German program. (Although Indian reports repeatedly refer to the Motorola “6800,” according to Motorola the 16-bit chip is the M 68000.) The timing of subsequent events showed continued parallel developments in the two programs.

The German aid in guidance is apparently continuing, despite the Agni launch. In May 1989, a DLR official said that “the APC-Rex program has not yet been concluded, but it will come to an end in 1989.”[8] West Germany was one of the seven countries that adopted the Missile Technology Control Regime in 1987, an agreement not to export items useful in making long-range missiles. That agreement barred the export of technology capable of real-time processing of navigation data, unless specific assurances could be given that the technology would not be used for, or transferred to, missile programs. If, as the evidence suggests, technology from APC-Rex has been used in India’s rocket and missile programs, Germany may have violated the agreement.

India has not described the Agni guidance system. But when the missile was assembled in 1988, Indian rocket scientists had studied and developed only one brain for rocket guidance: the German system based on the Motorola microprocessor and its software. Over a decade, Germany’s guidance tutorial helped India build and test a navigation package based on that system. Did that system go into the Agni, or did India invent from scratch some other system, not mentioned in any Indian space program report? If the latter, did the Indian rocket scientists block from their minds everything they had learned from the Germans? The evidence is strong that the Agni owes its brain to German engineering.

Interchangeable parts

The Indian space program first mentions the Agni in its 1982-83 annual report as a booster rocket for the Polar Space Launch Vehicle: six identical Agni boosters will lift the missile’s first stage. The boosters, in turn, are adaptations of the first stage of the SLV-3.[9] Indeed, the SLV-3 is the only large booster motor that India has: it carries nine tons of solid propellant, as does the Agni first stage; no other Indian booster carries anything close to that amount. India has used the same booster to lift the Advanced Space Launch Vehicle.[10] After the Agni launch a number of sources, Indian as well as foreign, reported that the Agni first stage was identical to the SLV-3 first stage. Thus, the main rocket for India’s missile program has come from India’s space program.

This same rocket, in turn, owes much to German help. Wind tunnels are essential to the design of any rocket. In 1974-75, DLR tested a model of the first stage of the SLV-3 in its wind tunnel at Cologne-Portz. DLR also helped India build rocket test facilities, furnishing a complete facility design and training Indian engineers in high-altitude testing. India has said it will use this technology to test the liquid-fueled upper stage of the Polar Space Launch Vehicle, and it may already have done so. India may also have used it to test the Agni’s liquid-fueled second stage, which must have been tested somewhere.

In June 1988, two Egyptian military officers were indicted for trying to smuggle carbon fiber composites out of the United States. Export of the composites was strictly controlled: the strong, lightweight, heat-resistant materials were being used for the nozzles and the nosecone of the MX, Trident, and Minuteman nuclear missiles.

But DAR began giving Indian scientists on-the-job training in composites at Stuttgart and Braunschweig in the mid-1970s. Subjects ranged from “glass fibre reinforced plastics via impregnated materials” to “carbon fibre reinforced composites.” The Indians learned “composition, manufacturing processes, quality control, and error detection.”

The German training allowed India to make rocket nozzles and nosecones of its own, which could be for either missiles or space launchers. To help the Indians use the composites, DAR supplied the documentation for a precision filament-winding machine, which India built and commissioned in 1985-86.

After the Agni test, Prime Minister Gandhi affirmed that one of the goals was to test “atmospheric reentry.” Lower-ranking officials were more specific. They said that the goal was to test a “domestically developed heat shield.”[11]

Target: China

No country, including India, has ever spent money on long-range rockets simply to explore space. The “satellites” launched by the SLV-3 were little more than flight monitors, used to transmit data on rocket performance, which was India’s true interest. To launch real satellites, India could and did hire other providers of that service. The Soviets launched India’s first two satellites; France’s Ariane rocket and the U.S. space shuttle have launched others.

Nor has any country developed long-range missiles simply to deliver conventional bombs. The large cost of missile development is only justified by the ability to inflict strategic blows, which conventional warheads cannot do.

The Agni, therefore, can only be interpreted as a step toward a long-range nuclear strike force. As India progresses in guidance, the Agni’s range should extend gradually to most targets in China.

India apparently has the material and skill to mass produce the Agni and arm it with nuclear warheads. The result will be a new nuclear equation in Asia. Across a common border, nuclear-armed rivals will confront each other, each with missiles, one or both vulnerable to a first strike from the other.

When India exploded an atomic bomb in 1974, the world was shocked. India had taken a Canadian reactor and U.S. heavy water both imported under guarantees of peaceful use and used them openly to make plutonium for a nuclear blast. That blast destroyed illusions about the “peaceful atom” and prompted changes in nuclear export policy. It is not surprising that India has again taken advantage of civilian imports and technology to further what appears to be a nuclear weapons program. What is surprising is that, given India’s record, it was so easy.

How a Satellite Guidance System Gets into a Missile

(Excerpts from program reports)


APC-Rex (German-Indian missile program satellite guidance program): received Motorola 68000 microprocessor

Indian space and missile program: “An engineering model of the Mark-ll based on the Motorola 6800 [sic] has been integrated and exhaustive tests are being carried out.”


APC-Rex (German-Indian missile program satellite guidance program): “Development of an on-board computer for autonomous payload control is in progress.”

Indian space and missile program: “Design review was conducted on inertial navigation systems with the participation of international experts.”


APC-Rex (German-Indian missile program satellite guidance program): “Design of the on-board [guidance] packages was completed.”

Indian space and missile program: “Design of on-board processors for SLV based on 16-bit microprocessors has been completed.”


APC-Rex (German-Indian missile program satellite guidance program): “Development and validation of hardware and software packages for APC-Rex are in their final stages.”

Indian space and missile program: “Breadboard models of on-board computers based on microprocessors have been realized.”


[1] P.D. Bhavsar et al., “Indian Sounding Rocket Program,” Proceedings of the 4th Sounding Rocket Technology Conference (Boston: American Institute for Aeronautics and Astronautics, June 23-26,1976), pp. 101-07.

[2] Letter from Arnold W. Frutkin, assistant administrator for international affairs, NASA, to Homi J. Bhabha, chairman, Indian Atomic Energy Commission, March 10, 1965.

[3] Steven R. Weisman, “U.S. Clears Vital Gyroscope for Indian Jet Fighter,” New York Times, April 7, 1988, p. A12.

[4] David Velupillai, “ISRO, India’s Ambitious Space Agency,” Flight International (June 28, 1980), p. 1466.

[5] “India’s Agni Success Poses New Problems,” Jane’s Defence Weekly (June 3,1989), p. 1052.

[6] Many of the following details of the German-Indian space program are found in the proceedings of a January 27, 1982, colloquium of the DAR (then called DFVLR) and the Indian Space Research Organization (ISRO) in Bangalore, India, “A Decade of Cooperation in the Field of Space Research and Technology,” and in annual reports of the Indian government’s Department of Space.

[7] Ted Greenwood, Qualitative Improvements in Offensive Strategic Arms: The Case of the MARV(Cambridge: Center for International Studies, Massachusetts Institute of Technology, Aug. 1973), p. 278.

[8] Letter from Dietmar Wurzel, head of DAR’s Washington, D.C., office, to Gary Milhollin, May 1, 1989.

[9] “India The Way Forward,” Spaceflight (Dec.1986), p. 434.

[10] “India Aims for Self-Sufficiency in Space,” Flight International (June 14,1986), p. 45.

[11] Barbara Crossette, “India Reports Successful Test of Mid-Range Missile,” New York Times, May 22, 1989, p. A9.