Why did the Iron Dome anti-missile system, which was once like a god, fail to stop the Kassan rocket?

Since 2012, the armed conflicts between Palestine and Israel, both large and small, have always seen Qassam rockets fired from the Gaza Strip into Israel, and the Iron Dome air defense system's tail trails over Israel and its successive interception bombing points have become a scene of the conflict. The Iron Dome was once a god-like existence. However, since October 7, the serious losses and psychological panic caused by the Qassam rocket attacks on Israel by Hamas armed forces have almost shattered the myth of the Iron Dome. So, what exactly is the problem?

Pictured: Israel deploys Iron Dome rocket interception system (Photo source: Baijiahao)

Frankly speaking, the Iron Dome is indeed an advanced air defense system. An Iron Dome air defense firepower unit consists of an S-band ELM-2084 multi-mission radar responsible for detecting and tracking threat targets; a combat management and weapon control center responsible for firepower allocation and engagement decisions; and three launchers, each equipped with 20 missiles. The weapon system has a range of 5 to 70 kilometers, and one firepower unit can protect an area of ​​150 square kilometers. The Israeli army has deployed 10 Iron Dome air defense firepower units.

There are multiple indicators that can measure the combat capability of air defense weapon systems. The first is the radar detection range. The early warning distance of the ELM-2084 radar is 470 kilometers, and the interception distance is 100 kilometers, which matches the range of the weapon. The second is the combat management capability. The radar can detect 1,100 targets at the same time, which is conducive to establishing a comprehensive air situation map. The third is the firepower density. It has a firepower channel that can intercept dozens of targets at the same time and has a certain ability to resist saturation attacks. The fourth is the continuous combat capability, with 60 rounds of ammunition on the rack and 120 rounds of ammunition in the position. The fifth is the interception probability. The interception probability at the target range is 90%, but the interception probability in actual combat is 75% to 80%.

It can be seen that the advantages of the "Iron Dome" air defense system are that the multi-task radar has a long warning and interception distance, a large number of targets can be detected at the same time, and the probability of single-shot interception is high. But the biggest problem is that the firepower channel and continuous anti-missile capacity are limited.

Figure 1: The battle between Kassan and Iron Dome (Source: Baijiahao)

Obviously, Hamas weapons have found the pulse of Iron Dome in the years of competition between Qassam and Iron Dome, and used a seemingly simple and crude but very effective method to directly hit the vital point of Iron Dome, that is, the high-attack flow salvo penetration of Qassam rockets. The launch density reached 5,000 rockets in 20 minutes, far exceeding the calculation and processing capabilities of ELM-2084 radar. The firepower channel of Iron Dome system was instantly blocked. The high-tech defense system could only sigh to the sky and admit defeat in the face of ultra-dense, low-tech and strong penetration means!

So can we increase the probability of interception by increasing the number of Iron Dome deployments and expanding the number of fire channels? In theory, it is feasible, but in practice it is basically impossible. The limiting factor is cost. The cost difference of at least 90 times between interceptor missiles and rockets may quickly put the defender into an unsustainable state of resource exhaustion.

It can be seen that the contest between "Kasan" and "Iron Dome" is like a football game. "Iron Dome" is just a strong "goalkeeper". If there is no forward of its own to put pressure on the opponent through attack, the "Iron Dome", the "goalkeeper" who blocks left and right, will soon be tired. It is only a matter of time before "Kasan" scores.

Wang Mingzhi, a military expert, joined the Air Force in June 1980, received a master's degree in military science in 1991, and a doctorate in military science in 2000. He was a professor at the Air Force Command College and held the rank of professional technical colonel.

Produced by: Popular Science of Chinese Military Technology

Producer: Guangming Online Science Department

Author: Wang Mingzhi (military science writer)

Scientific review: Fei Boyu (senior military content editor)

Planning: Jin He