In August 2022 Iran sold Russia over 2,000 Shahed 131 and 136 cruise missiles. Russia apparently has a manufacturing license as well. Russia apparently favors the 200 kg (440 pounds) Shahed 136 over the slightly smaller 135 kg (300 pound) Shahed 131. Both aircraft have similar flight characteristics. That means four or five hour endurance at about 180 kilometers an hour and explosive warheads with 15 or 25 kg (33 or 55 pounds) of explosives. Shahed 136 is believed to cost about $50,000 each, with most of that ($30,000) the gasoline engine. Both missiles use GPS navigation with a crude INS (inertial navigation system) backup. These missiles fly low (a few hundred meters at most) to avoid radar detection. These missiles are launched from a truck mounted launcher carrying four or five missiles in a box type storage/launch container. A small rocket is attached to the bottom of the missile to get it airborne and the engine running. The rocket is then supposed to fall away. GPS locations have to be entered into the GPS system before launch. Given the cost of key components there is not much of an advantage purchasing the Shahed 131.
The Ukrainians quickly developed tactics to defeat the Shahed 136s used against military targets. The low flying Shahed 136 engine is so loud it can be heard several kilometers away and, while rifle and machine-gun bullets are not very effective against it, larger caliber weapons like 12.7mm machine-guns and 20mm or larger autocannon are lethal to the Shahed 136. Another vulnerability of the Shahed 136 was that its inexpensive components were often unreliable and a large portion of them fail before reaching a target. These usually crash land intact, allowing detailed analysis of components and construction. Another vulnerability is to electronic AUD (Anti-UAV Defense) systems that employ jamming and other EW (Electronic Warfare) techniques to disable UAV guidance systems.
Ukraine has already been sent an AUD (Anti UAV Defense) system called Vampire. This system is palletized - all components are secured on a shipping pallet that can be mounted in a light truck, and consists of a telescoping mast mounting a electro-optical/infrared modular sensor ball and laser designator, a generator for power and Fletcher launcher that carries four APKWS 70mm laser guided rockets. These weigh only 15 kg (32 pounds) each and have a range of about a thousand meters when fired from the ground. Vampire can be used to detect and fire APKWS laser guided rockets at air and even ground targets. Any UAV, cruise missile or helicopter within range is vulnerable. Vampire is designed to be reconfigured, which is the kind of system Ukrainians prefer. The Fletcher launcher is designed to use the new, longer range APKWS rockets that gain additional range by having a larger rocket motor which makes the APKWS longer. Ukrainians are expected to modify Vampire to better suit their needs or simply to obtain longer range while carrying more rockets ready to fire.
Ukraine has the people and manufacturing ability to quickly develop an AUD system that relies on jamming or disabling the guidance systems of UAVs like Shahed 136. Ukrainian countermeasures have already led Russia to use Shahed 136 against cities and other civilian targets. These large-area targets are more difficult to defend with AUDs. That means more Shahed 136s hit something, even if it’s a building. The small Shahed 136 warhead does not do a lot of damage but Russia is running out of larger guided missiles and has been depending more on large unguided rockets and old ASM (Surface to Air Missiles) modified for hitting ground targets. The larger and faster guided missiles are saved for important military targets while the smaller missiles, like Shahed 136 are used against infrastructure and civilians. This is supposed to demoralize Ukrainian civilians but it has the opposite effect, making Ukrainian angrier at the Russians and more determined to drive them out of Ukraine.