Military Knowledge: Fattah-2 Hypersonic Missile

The Fattah-2 missile utilizes the configuration of hypersonic cruise missiles. The acronym HCM, which stands for Hypersonic Cruise Missile, is written on its nose cone. The shape and combination of the nose cone is similar to the X-51 hypersonic cruise missile. However, the X-51 missile uses a ramjet engine that requires air intake, whereas in the Fattah-2 missile, air intake and ramjet engines are removed, and instead, a liquid fuel rocket engine is used. This will not affect the missile’s performance.

Design:
The Fattah-2 missile consists of two parts. The first part is the Fattah solid fuel booster, which has not changed from the initial version. The second part is the gliding warhead, which separates from the booster and has a liquid fuel rocket engine.

The overall shape of the Fattah-2 gliding warhead is very similar to the Boeing X-51 missile, but with the difference that its air intake has been eliminated and a rocket engine is used instead of a ramjet engine.

The explosive material is located at the beginning of the warhead, followed by an inertial guidance and GPS system along with a computer that is responsible for guiding the warhead to the final stage of impact. After the guidance system, there is a detonator container (yellow piece), followed by a liquid fuel tank and an oxidizer tank, and finally a rocket engine that appears to have the ability to change the missile’s trajectory.

At the end of the warhead, there are four fins, two of which form a line with the bottom of the warhead and are fixed, responsible for producing lift force. The other two fins are designed to change direction and have the ability to rotate around an axis connected to the body.

The speed of this missile is stated as Mach 10 in some sources, but it is unclear for how long this speed can be sustained. However, it can be assumed that the speed exceeds Mach 5 at the moment of impact.
The range of the missile has been reported as 1500 to 1800 kilometers by some news agencies, but it is unlikely that the range will be significantly different from that of the Fattah-1 missile, and a range of less than 1400 kilometers does not seem reasonable for Iran’s operational needs.

Read more: Military Knowledge: Fattah Hypersonic Ballistic Missile

The operation of the Fattah-2 missile:
The solid fuel booster of the Fattah-2 missile carries it to a certain altitude from space, and then the warhead separates from it and moves towards the atmosphere. In this state, the missile will travel at a fast falling rate until it reaches the atmosphere, and then, like an HGV (Hypersonic Glide Vehicle), it will glide to the ground in the atmosphere at an altitude of less than 100 kilometers. Considering the high speed announced for the Fattah booster in Fattah-1, it must be more than Mach 15 at the time of entering the atmosphere. Therefore, due to the high lift force of the Fattah-2 warhead, it must spend a considerable amount of time gliding in the atmosphere and continuously reduce its altitude.

In a part of the middle stage and at the end of the warhead, it drastically reduces its altitude and its speed also decreases. In this stage, the rocket engine embedded in the warhead turns on and stabilizes the warhead’s speed at Mach 5 or higher. The Fattah-2 warhead spends a lot of time at low altitudes and will cruise through the final stage of its path like cruise missiles thanks to its engine. A significant point is the amount of drag force and tolerance for high-speed entry into the atmosphere because aerodynamically, the warhead is not designed for such speeds.

Conventional designs of hypersonic cruise missiles use a booster for initial speed and a ramjet engine for further movement along their path, and they are often launched from aircraft. These engines have a risk of reducing their speed to less than Mach 5 at their maximum range due to fuel shortages. However, Fattah-2 uses a solid fuel ballistic missile booster for movement in a part of its path and reaching an initial speed of more than Mach 15, which provides the missile with a considerable speed for a long time. Then, at the end of its path or near the point of impact, it uses an engine to compensate for the speed reduction and stabilize its speed at Mach 5. This is an interesting and very creative idea that has been implemented by Iranian experts. This initiative eliminates the limitations of HGVs for the Aerospace Force of the Islamic Revolution Guards Corps (IRGC).

Unlike conventional HGV versions, the Fattah-2 warhead is more suitable for flying at low altitudes. Most HGVs travel much of their path at an altitude of less than 100 kilometers and more than 30 kilometers, where air density is lower. However, the Fattah missile can fly in an altitude of less than 12 kilometers due to its aerodynamic shape, but it seems to try to maintain itself at an altitude between 12 and 30 kilometers to experience less speed reduction. Overall, the Fattah-2 missile is more of a hypersonic glide vehicle than a hypersonic cruise missile. However, its performance includes both types of hypersonic missiles.

It can be said that the operation of the Fattah-2 missile is a completely unconventional definition compared to other conventional hypersonic missiles, and the Fattah-2 missile has created a new classification and standard in this field: Hypersonic Cruise Glide Vehicle (HCGV).

It should be mentioned that the feature of not using a ramjet engine does not exclude this warhead from the hypersonic category. Also, using a rocket to start flight and fly into space cannot prevent the cruise flight of intermediate and final stages. Iran’s technology in making ramjet engines for use in long-range hypersonic weapons has not yet reached its final evolution. Therefore, having all the components available and the ability to mass-produce Fattah-2 is a suitable and creative solution to overcome the current technological gap. Clearly, this technological bottleneck will also be resolved in the near future.

Specifications of Fattah-2 hypersonic missile:
Type: Hypersonic Glide Vehicle (HGV)
Country of Origin: Iran
Producer: IRGC Aerospace Force
Unveiled: 2023
Length: ~ 12 meters
Diameter: 80 cm first part, 50 cm second part
Fuel:
First stage: solid
Second stage: liquid
Range: more than 1400 km
Speed: ~ Mach 5 (in the last phase), ~ Mach 15 (in the first phase)
Weight: 3500 to 4100 kg
Warhead: ~ 500 kg
Explosives weight: ~ 200 kg
Guidance: combination of INS and GPS

More images of Fattah-2 missile:

Infographics of Fattah-2 hypersonic glide vehicle in Russian, Hebrew, Farsi and Azeri: