These constraints explain why the illicit proliferation of liquid-propellant missiles has been confined to engine systems available for purchase, namely the Scud and the No-dong, as well as the Soviet-era SA-2 Volga, which can be bought from Polish scrapyards. Proliferators wishing to develop longer-range liquid-fuel missiles must rely on clustering or stacking engines, whether imported or produced indigenously. This limits design flexibility and has yielded little success. North Korea has attempted to build such missiles from existing engine designs, basing its three-stage Taepo-dong missile on the Scud engine. However, Pyongyang's engineers have yet to fly a Taepo-dong to its intended target.
Despite their straightforward design, solid-fuel motors do not lend themselves to reverse engineering. While it is possible to chemically analyse the propellant grain to determine its constituent compounds, this will not reveal the processes required to prepare, mix and cast it. The 'recipe' is more important than the list of ingredients, and the accumulated knowledge of how to assemble the recipe is even more vital.
Because small solid-fuel rocket motors are used in various conventional weapons – including artillery rockets, air-defence missiles and air-to-air missiles – many countries have the industrial and technological foundations to produce them. The knowledge and experience accrued through the production of small-calibre motors provide a basis for the manufacture of larger motors.
However, the learning process is slow and subject to setbacks. As well as patience and persistence, specialised production equipment that is subject to export controls is required, including much larger temperature-controlled mixers, casting chambers and non-destructive testing devices.
Over the decades, a consistent and recognisable pattern has emerged of a country's evolving capacity to build larger and more powerful solid-fuel motors. This might be expected to start with the production of motors containing a few hundred kilograms of solid propellant and to proceed by trial and error to increasingly larger motors. One-tonne motors with a 50-centimetre diameter might lead to two-tonne motors with a diameter of 60–70cm. These evolutionary steps generally take several years of sustained investment and effort.
Iran's missile-development pattern seems to have broken from the incremental approach taken by France, China, India, Pakistan and others. In May 2005, the defence minister referred to the development of a solid-fuel equivalent to Shahab-3 and in November 2007 there was a reported test launch of an Ashura missile similar to the Sajjil. Iran appears to have made a significant jump from the two-tonne Zelzal motor to the Sajjil's ten-tonne first-stage motor. This suggests it may have received technical assistance from foreign sources with experience of producing large solid-propellant motors, as well as having acquired export-controlled propellant-production equipment.
Implications
With the launch of the Sajjil, Iran appears to have established the industrial infrastructure and technological foundation to begin efforts, on its own, to support the eventual development, design and production of much larger, more powerful rocket motors. If so, these developments are similar to those achieved by Tehran in the nuclear arena, where Iranian engineers have mastered the ability to enrich uranium sufficiently to power a civilian nuclear reactor, and have established the wherewithal to produce highly enriched uranium for a nuclear bomb in the future, if so desired.
Recent developments have heightened Western fears about Iran's missile capabilities. But before being able to deploy the Sajjil missile Iran would first need to establish a production line for solid-fuel rocket motors to strict performance criteria. This would require many static test firings and test launches over the next three to five years.
Among other remaining technical challenges, Tehran still needs to develop and incorporate sophisticated navigation, guidance and control systems for its future missiles. It does not possess the technical skills to produce the necessary navigation components indigenously, but the history of missile proliferation has shown that these can be purchased from Russian, Chinese and other foreign suppliers. In addition, Iran has yet to show it has developed thermal shielding to protect a long-range missile warhead during re-entry into the atmosphere.
If Iran is now able to produce long-range, solid-propellant missiles capable eventually of hitting targets in Europe, an intercontinental ballistic missile capability could follow. However, missile advances will not occur suddenly. Iranian success will rely upon a test and demonstration programme involving multiple test flights. These can be tracked by Western intelligence and should provide considerable warning.
1 | 2
< Previous
