According to foreign media reports, in January of this year, the 155mm ramjet powered shell has entered the final stage of development, and preliminary testing of this new type of shell will soon begin. Unlike traditional shells fired by barrel guns in various countries, the 155mm shell developed by India uses a ramjet engine to increase its range. With the help of this engine, the projectile may have a range that is 1.5 times longer than before without the need to redesign the cannon. This type of shell is commonly referred to as a "ramjet extended range shell". When it comes to the word 'extended range', many people immediately associate it with types of missiles such as pit shells, bottom row shells, rocket assisted extended range shells, and rocket assisted gliding extended range shells. The principle of increasing the range of ramjet extended range shells is similar to that of rocket assisted extended range shells, but the power after launch is provided by a ramjet engine instead of a rocket engine. Similar to rocket engines used in shells, ramjet engines are also propulsion devices with almost no moving parts. Its structure is simple, mainly relying on the intake compression effect generated by the high-speed flight of the projectile to generate thrust. But unlike rocket engines, ramjet engines do not need to carry large amounts of oxidizer during operation, so shells have more space to carry fuel, and the specific impulse of ramjet engines is higher, which helps increase the range of shells. India is not the only "test taker" in the development of ramjet extended range shells. Defense companies from some countries have also explored this area and achieved certain results. Last May, at the defense exhibition held in Madrid, Norwegian company Namo unveiled its developed 155mm ramjet extended range shell. This type of shell is propelled by a solid fuel ramjet engine and has a range of up to 150 kilometers. This type of shell can be fired from NATO standard 39, 52, and 58 caliber barrel guns, and can also strike targets on land, in the sea, and in the air in various combat scenarios. Last year, the American company Tiberius Aerospace launched its developed "Scepter" 155mm ramjet extended range shell. According to relevant public information, this type of shell can also be fired using conventional barrel artillery that meets NATO standards. With the assistance of a ramjet engine, the "Scepter" can reach a maximum flight speed of 3.5 Mach, fly at an altitude of over 19.8 kilometers, and have a range of 140-160 kilometers. The achievement of these results, as well as the continued efforts of more countries and companies in this area, to some extent, indicate a possibility that ramjet extended range shells will soon enter the battlefield. (New Society)