FOR OTHERWISE Ten incoming rockets, Israel’s mobile defense battery system, the Iron Dome, usually shoots down nine. Israel claims it has maintained that ratio even as Hamas has fired larger salvos from Gaza following the Islamist group’s October 7 attack on Israel. However, Iron Dome has limitations. In particular, it is expensive to replenish transitional stocks, even with the help of American manufacturing. Reported costs for one interceptor, called Tamir, range from $40,000 to more than double that. So Israel plans to deploy laser air defenses. It was the first country to establish such a system. How does Iron Beam, as the system has been called, actually work?
Israel’s defense ministry decided to phase out Iron Beam last year after it destroyed rockets, mortars, drones and anti-tank rounds in tests. As Naftali Bennett, who was prime minister at the time, said, Israel would build a “laser wall”. The works were expected to start in 2025. Now, with a war going on, the timeline is being crushed. The big selling point, says Uzi Rubin, former head of Israel’s Missile Defense Agency at the defense ministry, is the Iron Beam’s unlimited magazine. Laser sights are “made to run”, he notes, each with a few dollars’ worth of diesel in an electric generator.
Iron Beam is a technological marvel. The moving laser guns use a complex arrangement of mirrors to redirect photons from light-emitting diodes into a single beam. To prevent the mirrors from melting, they were designed with special reflection and cooling systems. After 10km of travel, the Iron Beam laser is said to have a base diameter and is very accurate, despite the distorting effects of wind and air temperature.
But as intimidating as Iron Beam’s 100-kilowatt (kW) lasers are, Dr. Rubin warns that widespread expectations of “Star Wars performance” are unrealistic. Experts believe that the range of the Iron Beam, at best, will be a little more than a third of the Tamir missiles, which can hit targets even 70km away. Israel’s state-owned developer Rafael has spoken of an area of ”several thousand”. One limitation is that the weather can affect the system – moisture and particles, such as smoke, absorb laser energy.
Another disadvantage is “dwell time”. It takes several seconds of engagement for the Iron Beam laser to pump enough energy into a spinning rocket to disintegrate or explode. An Iron Beam gun will therefore not be able to sustain a heavy interception, so the system will be used in conjunction with an Iron Dome, which fires interceptor volleys quickly. Iron Beam also pulls target data from Iron Dome’s network of radars and high-speed computers. And the new system’s lasers might be better suited to fighting slower attack drones, which don’t spin and rely on delicate rotors, wing flaps and guidance systems, so the shoot down with shorter laser bursts.
One concern is that Hamas and other militant groups may be able to coat rockets in heat-resistant material. And the installation cost of Iron Beam batteries is huge (although not disclosed). Yaakov Amidror, a retired major general and former head of Israel’s National Security Council, says it remains to be seen whether Iron Beam fires enough rockets to justify the investment.
Other laser air defenses are planned. Lockheed Martin, in December 2022, signed an agreement with Rafael to jointly develop a version of Iron Beam for the American forces and, possibly, their allies. The US The Air Force Research Lab’s “directed energy” team in Albuquerque, New Mexico, is developing 300kW class lasers to defeat what wargaming suggests could be “terrible salvoes” of missiles , according to Nicholas Morley, senior scientist at the lab.■
