Iraq Survey Group Final Report
Solid-Propellant Missile Developments
The Iraqi composite solid-propellant missile program that developed in the 1990s supported the development of a short-range ballistic missile (SRBM) system allowed within the UN limitations and the refurbishment of and improvement to existing weapon systems and attempted to support the development of ballistic missile systems prohibited by the UN.
Al Fat’h Missile Program
Despite the limitations imposed by the UN sanctions and the international arms embargo, Iraq was able to produce and field the domestically designed Al Fat’h composite solid-propellant ballistic missile. The goal of the program, which commenced in June 1997, was to develop a missile that could deliver a 300-kg payload to a range of 150 km with an accuracy of 150 meters Circular Error Probable (CEP). The accuracy requirement for an unguided version of the Al Fat’h was 750 meters CEP.
- The Al Fat’h program began under the Ababil-100 project in the early 1990s. By 1994 the liquid- and solid-propellant missile development programs under Ababil-100 had split, and the solid-propellant program retained the Ababil-100 name. According to a senior Iraqu missile official, the first technical review meeting was held for the commencement of the Al Fat’h missile program in June 1997.
- The Al Fat’h was designed to carry unitary HE or submunition warheads. ISG has not found evidence to suggest the Al Fat’h was intended for use with chemical, biological, or nuclear warheads.
By the time of OIF, Iraq had produced between 100 and 120 Al Fat’h missiles, with up to 60 consumed in the development process. In late 2002, the Army had few alternatives and accepted the unguided Al Fat’h, with the understanding that the guided variant would continue to be developed. Between 50 and 60 missiles were provided to the Army, all of which were unguided; five were equipped with submunition warheads.
- During OIF, Iraq fired between 12 and 16 Al Fat’h missiles at Coalition targets, and between 4 and 13 missiles were damaged or destroyed by the Coalition. After the war the Coalition recovered at least 10 missiles, which leaves up to 34 unaccounted for missiles.
Al Fat’h development allowed Iraq to create and refine the technical expertise and develop the infrastructure needed to support the design and production of missiles with ranges beyond those allowed by the UN. The Al Fat’h design was conservative and used unnecessarily heavy airframe components, yet the missile reached and in some cases exceeded the 150-km limitation imposed by UNSCR 687 in flight tests and during operational launches.
- Computer modeling of the Al Fat’h provided an estimated range capability of 180 km. Using lighter airframe materials would improve the range.
Key elements of the Al Fat’h development process required foreign assistance or procurement. ISG has discovered that the guidance for the Al Fat’h was to consist of a “strap-down” inertial navigation system (INS) with gyroscopes and accelerometers, which would fall well beyond the production capabilities in Iraq. Also, key ingredients of the composite solid-propellant could not be produced in Iraq.
The Al Fat’h missile (see Figure 6) was a solid-propellant ballistic missile weighing approximately 1,200 kg with an overall length of approximately 6.7 meters and a diameter of 0.5 meter for the main body and 1.4 meters with the aft fin assembly. While forward canards were used on a number of missile test flights, they were not used on the Al Fat’hs provided to the Army, and none have been noted on the Al Fat’hs captured to date.
- The airframe was primarily constructed from 4 mm thick 30CrMoV9 sheet steel. While 30CrMoV9 proved difficult to form, the extensive use of this alloy throughout the airframe simplifies missile construction. Although not available, maraging steel would have been the preferred material. The aft fin assemblies and nose cones were constructed of aluminum.
The Al Fat’h was designed to be launched from a Transporter-Erector-Launcher (TEL). Based upon the SA-2/Volga missile launcher, the Al Fat’h missile was mounted in a launcher-storage box with an integral launcher rail.
The Al Fat’h used a composite solid-propellant motor of conventional design and composition. According to a senior official in the Iraqi missile program, the final motor mass was 828 kg, although the motors varied from 820 kg to 856 kg because of variations in motor insulation. Other documentation retrieved by ISG give a propellant mass of approximately 770 kg. ISG believes that the variations in propellant mass suggest that the final design for the missile was not frozen. Manufacturing the Al Fat’h solid-propellant motor presented several challenges. Specifically, Iraq lacked preferred materials for the motor case and insufficient solid-propellant mixing capacity.
- Iraq lacked maraging steel sheets of sufficient size and quantity to manufacture Al Fat’h motor cases. Maraging steel has the advantage of being easy to form in its original state but, when annealed, provides excellent rigidity, strength, and crack resistance. Without maraging steel, the Al Fat’h motor case had to be constructed from 30CrMoV9 sheet steel (see Figure 7 for an Al Fat’h motor). Difficulties in forming and aligning the cylindrical shapes needed for the rocket motor cases from this material led to large miss distances, according to a senior official in the Iraqi missile program.
- Iraq lacked sufficient propellant mixing capacity. The mixers and bowls acquired in the late 1980s for the BADR-2000 program would have sufficed, but these were not available (see Infrastructure section). Instead, the Iraqis were forced to use four or five smaller 30-gallon bowls to mix the propellant needed for a single Al Fat’h motor, according to a senior official (see Figure 8). These bowls, using two mixers, were then poured sequentially into the motor casing. While one senior Iraqi official stated the process worked well, he also admitted one out of every 10 motors exploded during motor burn. The use of multiple bowls presented the potential for uneven curing of the propellant and inconsistent motor performance. In addition, this process also eliminated the possibility of multiple simultaneous motor castings.
Solid propellants can be divided into two classes: Double Base (DB) and Composite propellants.
- DB propellants contain two primary ingredients: nitro-cellulose and nitro-glycerine. DB propellants can be extruded (Extruded Double Base—EDB) or cast (Cast Double Base—CDB) to form a variety of shapes.
- Composite propellants are a mixture of finely ground oxidizer (commonly ammonium perchlorate), fuel (commonly aluminum powder), and a polymeric binder (commonly HTPB). These ingredients are mixed and cast into the motor case. The motors spend days at elevated temperatures to cure the propellant, giving it the correct physical properties.
Composite propellants have a higher combustion temperature and higher performance than that of the DB type. They are also safer but more complex to manufacture than DB propellants.
Rocket or Missile?
Although the Al Fat’h systems fielded with the Army and fired during OIF were unguided and therefore technically rockets, the Iraqi intent was to field a missile. Because of this ultimate goal, the Al Fat’h is referred to throughout this document as a missile.
Guidance and Control
The unguided Al Fat’h used simple aft stabilization fins. The guided version of the Al Fat’h would have had a relatively complicated control system, with canards, actuators, and a strapdown INS with an indigenously developed computer and imported gyroscopes and accelerometers. Iraq specified an INS accuracy of 1 degree per hour drift, which is relatively sophisticated. Iraq also considered using Global Positioning System (GPS) guidance.
- A highly accurate strap-down system, coupled with an adequate canard guidance system, would most likely have provided the Al Fat’h with the specified 150-meter CEP accuracy for the guided variant at a range of 150 km. That level of accuracy coupled with the submunition warhead would have made the Al Fat’h a formidable tactical delivery system.
- The instrument/control section of the airframe, while of an unnecessarily heavy construction, is constructed using the same material as the rocket motor casing, thereby simplifying manufacture.
- The planned guidance package for the Al Fat’h would have broken new ground for Iraq by attempting to incorporate aerodynamic flight controls onto a ballistic missile. While a proven concept in some countries, this was the first attempt by Iraq to incorporate this type of control system into a ballistic missile.
- Iraq attempted to acquire Guidance and Control (G&C) components and technology from a number of foreign sources. Iraq reportedly received a sample inertial system from the FRY, but it was considered inadequate and of poor quality (see the Delivery Systems Procurement section for more details). There reportedly were 50 G&C sets delivered from Belarus prior to the start of OIF, according to a source with good access, although ISG has no confirmation this delivery actually occurred.
- Augmenting the Al Fat’h strap-down INS and canard controls with inputs from the GPS would have further increased system accuracy.
Despite the lag in procuring the INS and testing delays, design work on the G&C for the Al Fat’h was well under way prior to OIF. Two guided flight tests were conducted prior to the war, one with roll control and a second with pitch control. According to a high-level official within the missile program, in March 2003, Iraq was only a matter of weeks from conducting a test flight with a full control system (equipped with INS and canards). ISG believes that Iraq did not conduct this flight test because, in December 2002, the UN had ordered that Iraq cease all missile tests until further notice. While this system would have used a prototype guidance system built from available components and be less accurate than desired, it would have allowed the Iraqis to validate the concepts and techniques.
ISG has learned through debriefings of senior Iraqi officials that there were originally three warhead designs proposed for the Al Fat’h: a unitary HE warhead, a conventional submunition warhead, and a miscellaneous warhead initially suggested to be a Fuel Air Explosive (FAE) warhead. The army accepted both the HE and submunition warheads, but the FAE warhead was not pursued (see Figure 9).
- According to documents recovered by ISG, in 2002 the SSM Command presented a requirement for 100 guided Al Fat’h missiles, 20 of which were to be equipped with submunition warheads and the remaining 80 with HE warheads, to the Al Rashid General Company.
The Al Fat’h HE warhead was the same as the Al Samud HE warhead discussed earlier, which had been derived from the Scud HE warhead. Sharing the same missile diameter and interface as the Al Samud allowed for savings on production costs and facilitated the interchange of warheads, although the Al Fat’h warhead SAFF and arm circuit required adaptation due to the higher acceleration profile of the Al Fat’h during launch.
- The HE payload mass varied between 260 kg and 300-kg and contained 160-170-kg of HE. Figure 10 shows an X-ray of the Al Fat’h unitary HE warhead with a damaged impact or crush switch located in the nose tip.
Strap-Down Inertial Navigation System Tutorial
One of the major costs and maintenance factors in an inertial guidance system is related to the use of complex mechanisms required to control the attitude of the platform. If individual gimbaled gyroscopes are used, then this adds to the system error budget. One approach to eliminating these problems is the strap-down inertial guidance system.
In a typical strap-down system, the gyroscopes and accelerometers are mounted on a very rigid structure on the missile. Instead of using gyroscopes to keep the accelerometers pointed in a constant direction, a strap-down system allows the accelerometers to rotate with the missile and uses the gyroscopes to keep track of where each accelerometer is pointed. Because the accelerometers are no longer oriented along convenient reference axes, the mathematics become more complex; but, with digital computers, this is no longer the obstacle it once was.
Strap-down inertial guidance systems offer improved reliability, lower costs, and the potential for integration with other flight controls. The keys to strap-down performance are the gyroscopes and the software. Because of these characteristics, the strap-down inertial guidance system is ideal for short-range ballistic missile systems.
- The fuze, activated by the impact of the warhead on the ground, sends a firing signal to a booster charge, which in turn detonates the main explosive charge. Figure 11 shows the basic layout of the unitary warhead.
There is no evidence to suggest that unconventional warheads were to be developed for the Al Fat’h missile. However, as a direct extrapolation of the Scud conventional warhead design, the Al Fat’h HE warhead inherits the same primitive design that could allow modification to accommodate bulk-filled chemical or biological agents.
- Iraq retained the intellectual capital for reproducing the crude “special” warhead (CBW) design for the Al Husayn missile, so modification and production of this type of warhead could be achieved in a matter of weeks with a relatively small team of specialized individuals.
A senior Iraqi missile official indicated that submunition warheads were deemed to be more effective than unitary HE because they would have a larger lethal footprint and reduce concerns over poor missile accuracy. Iraq researched a variety of different configurations for the Al Fat’h submunition warhead before finally arriving at a design containing 850-900 submunitions.
- These submunitions were based on FRY anti-personnel/anti-tank KB-1 submunition identical to those used in the Ababil-50 submunition payload.
- The submunitions are stacked on top of one another and held in place by foam molds (see Figure 12).
The KB-1 submunition is an open-ended tube, housing a copper-shaped charge (see Figure 13). Upon detonation, the body fragments and scatters the ball bearings surrounding the outer shell, and the shaped charge fires, projecting the jet forward to penetrate the target. Typically, the submunitions contain 30 g of explosives.
- ISG judges that it is not possible to modify the KB-1 submunition to accommodate chemical or biological agents. Considering the small internal volume of the submunitions and risk of agent fratricide from the explosive charge, the KB-1 submunition is not a candidate for chemical or biological agent dissemination.
The shell case of the Al Fat’h submunitions warhead, manufactured by Al Rashid, was 3 mm thick and constructed of aluminum. The original design called for an aluminum warhead base, but the warheads produced used steel due to material shortages. The additional weight of the steel in the production warheads meant they could carry only 740 to 760 submunitions. Further, due to limitations in manufacturing technology, the warhead shell was conical rather than the aerodynamically optimum ogive design.
- Al Rashid General Company began Al Fat’h submunition warhead development in July 1998. Development continued through 2002, including five static tests, three of which were successful.
Iraq used detonator cord to fragment the warhead and let the airstream disperse the submunitions. Initially, Iraq wanted to use a single burster charge in the center of the warhead to disperse the submunitions after the detonator cord fractured the warhead and aerodynamic forces peeled back the skin. Experiments using a live burster charge were conducted in April and August 2002 and successfully dispersed 850 submunitions over an area of a 600-meter radius. During one flight-test, however, the burster failed to detonate. The airstream passing over the exposed submunitions dispersed the submunitions, and fewer munitions were damaged than experienced in previous experiments.
- As a result of this test, Iraq removed the explosive from the burster, but the empty burster tube was left in place to preserve structural support. Figure 14 is an X-ray of an Al Fat’h submunition warhead airshell. The black line running parallel with the sides of the warhead casing shows the detonator cord.
- Figure 15 illustrates the arrangement of the submunitions about the burster tube located along the central axis of the warhead.
Early attempts to use timing and barometric fuzes for altitude bursts of the submunition warhead failed. The problem was resolved (see Figure 16) by employing a diaphragm switch from the Scud barometric sensor and a battery from an Ababil-50 rocket.
In operation, the warhead is armed by the action of the “G” Switch through a sustained acceleration of 7.5 G for a minimum of 2.5 seconds. A barometric sensor detects altitude; when the missile ascends to a height of 5.5 km, a thermal battery is connected, charging the capacitors within the firing circuit. As the missile descends through 3 km, the capacitors discharge providing power to the detonator, which in turn initiates the detonation cord and the booster rod.
- In practice, the height of burst for submunition dispersal was approximately 2 km (2 km +/- 500 m), according to an official within the Iraqi missile program. Even with knowledge of the target terrain, such a loose tolerance is undesirable. (Figure 17 depicts an Al Fat’h missile with a submunition warhead.)
- Iraq intended to introduce a “strap-down” INS for the Al Fat’h missile in which presets that relate directly to predetermined burst altitudes (defined through time, velocity, and trajectory) could be configured before launch. Such a system has intrinsically greater accuracy in determining altitude than a barometric sensor.
ISG, through document exploitation and debriefings of senior Iraqi officials, developed a detailed accounting of the Al Fat’h test program. This test program, conducted between early 2000 and late 2002 consisted of approximately 50 individual firings, about 17 static motor tests and about 33 or 34 flight tests. A detailed breakdown of Al Fat’h missile launches and motor tests is included in the Delivery Systems Annex.
- Between 2000 and 2001, 10 or 12 solid-propellant rocket motor static tests were conducted at the Al Musayyib Solid Rocket Motor Support and Test Facility at Al Mutasim. Approximately midway through the static testing program, missile flight-testing began. This approach allowed modifications to the motor design to correct errors discovered during the flight-testing.
- The testing program passed through various phases as the emphasis shifted from motor performance and basic flight characteristics, to accuracy, reliability, and missile acceptance testing.
- Flight-testing began in 2000 and ended in late 2002. By mid-2001 to late 2002, Al Fat’h flight tests provided relatively consistent range performance using inert, submunition, and unitary HE warheads. The last two flight tests constituted the acceptance tests for the unguided variant of the missile.
- The flight-test program did have difficulties and never achieved the 750-meter CEP expected for the unguided airframe. The system also experienced a high failure rate during testing with 30% ending in failure and 10% of the motors experiencing catastrophic failure during firing.
While there are some firm production numbers for aspects of the Al Fat’h missile program, such as the number of missile flight tests, estimates for the total number of missiles produced and the number of missiles delivered to the Army vary widely. Captured Iraqi documents and other material provided by senior Iraqi personnel provide a breakdown of warheads, motors, missile airframes, and missile acceptance inspections for the years 2000 through 2002 (shown in Table 3). Based on these numbers, missile production probably was limited by Iraq’s ability to produce rocket motors.
- While the figures reflect 95 missiles accepted by quality-control inspections by 2002, only 92 rocket motors had been produced. In addition, approximately 11 rocket motors were consumed in static testing for propulsion system development.
- The use of inert warheads in the early test flights may account for the relatively low number of warheads (79) produced from 2000 to 2002. Following OIF, several inert Al Fat’h missiles were found, probably used for troop training.
If true, Iraq produced about 80 combat-ready missiles by the end of 2002. Thirty-three or 34 missiles were consumed in test flights, leaving about 45-50 missiles available. During the first months of 2003, more missiles probably were produced, probably no more than one per week. ISG judges that between five and eight Al Fat’h missiles could have been produced in 2003, given the typical time associated with propellant curing and missile assembly, coupled with the interruption in production as Iraq dispersed material in anticipation of or in response to Coalition attack. Taking these assumptions together, ISG estimates Iraq had between 50 and 60 Al Fat’h missiles available at the onset of OIF.
- These numbers generally agree with those provided by senior officials within the Iraqi missile program, where the number of Al Fat’h missiles provided to the Army varies from as low as 30 to as high as 60. Of these, perhaps five to eight were equipped with submunition warheads.
- During the war, Iraq fired between 12 and 16 Al Fat’h missiles. In addition, informal assessments of Al Fat’hs destroyed or damaged during the war vary from four to 13. To date, Coalition forces have collected at least 10 Al Fat’hs.
- Given the above numbers, the number of Al Fat’h missiles unaccounted for could vary from 0 to 34 (see Table 4). However, ammunition and weapon systems are being collected and destroyed all over Iraq, and a number of Al Fat’hs have been misidentified as FROG-7 or ASTROS battlefield rockets. A full accounting of Al Fat’h missiles may not be possible.
|Missile Accepted in QC Inspections
|Worst Case||Average||Best Case|
|Missiles Available to Army
The Al Fat’h was produced with materials allowed under UNSC resolutions, although a number of the ingredients in the Al Fat’h solid-propellant were subject to monitoring and verification under Annex IV of the Plan approved by UNSCR 715 (for a breakdown of specific propellant components listed in Annex IV, see the Delivery Systems Annex). Iraq attempted to acquire a number of these materials without the knowledge of the UN, and these efforts are noted in the Delivery Systems Procurement section.
The range capability of the Al Fat’h exceeded the 150-km limit imposed by the UN. A senior Iraqi official insisted the missile was designed to have a maximum range of 145 km with a 260-320 kg warhead, but, during flight tests between 2000 and 2002, the Al Fat’h flew beyond 150 km on at least eight occasions. The senior Iraqi official attributed the flights with ranges greater than 150 km to inaccuracies in the rocket motor insulation, resulting in greater than expected propellant mass.
- While Al Samud II tests with ranges in excess of 150 km were a factor in the UN’s decision to require that missile’s destruction, no decision by the UN had been made on the Al Fat’h prior to OIF.
- At least six missiles fired during OIF would have exceeded the 150 km range if not intercepted. The longest test flight declared by Iraq was 161 km, while the longest combat range probably would have exceeded this range.
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