Grenades Go High-Tech: Drones Deliver Explosives & Catch Drones Mid-Air

A hand grenade is a type of explosive device designed to be thrown by hand. The appearance of grenades similar to the modern ones is estimated to have emerged around 1,000 years ago, during the Middle Ages.

When we delve into history, we find that weapons were similar to grenades even in ancient times. One example is the “Greek Fire” bomb, utilized during the Peloponnesian War. This weapon operated by filling a jar or barrel with liquid gunpowder and then hurling it either by hand or with a catapult to set it ablaze, resembling what we now know as the “Molotov cocktail.” There are records of the Mongol army using small jars filled with oil, equipped with a fuse for throwing. In East Asia, these incendiary weapons were known as “Huǒjiū.”

The grenades that were developed in modern Europe were both powerful and dangerous. They typically took the form of softball-sized pottery or iron balls filled with gunpowder and a fuse. Soldiers would carry several of these grenades in a bundle, march up to enemy lines, light the fuses, and toss them. Skilled soldiers chosen for this task, often tall and well-built, came to be known as “grenadiers” and were assigned to assault missions that were considered almost suicidal.

In the modern era, spanning from the late 19th century to the early 20th century, as rifles replaced muskets and machine guns became commonplace, the role of grenadiers in throwing grenades diminished as it was seen as a near-suicidal endeavor. However, the significance of grenades experienced a resurgence during World War I when trench warfare became prevalent once again.

Origin of the Peloponnesian War ‘Greek Fire’

During the Russo-Japanese War, the British observation group noted the Japanese army’s effective use of grenades. Recognizing the potential utility of grenades in future battles, the British Army command developed the “percussion” grenade, famously known as the Hales bomb, in 1908. This marked the initiation of modern warfare’s reliance on grenades.

However, these early grenades often suffered from manufacturing flaws due to the era’s technological limitations, resulting in a significant risk of duds or accidents. It was not uncommon for soldiers in the trenches to prepare to throw grenades, only for the percussion fuse to accidentally strike the trench wall and detonate, causing them harm.

Consequently, percussion grenades fell out of favor and were gradually phased out. Instead, it became typical for soldiers on both sides to improvise their grenades by attaching explosives to wooden sticks or rods or by filling empty military ration cans with explosives and potential shrapnel. These makeshift grenades would be covered with lids and fitted with fuses, a design colloquially referred to as the “jam tin grenade.”

Another variation of such a grenade is the “stick hand grenade,” which remained in use until World War II. In modern warfare, the primary type of grenade is the ‘delayed fuse’ grenade.

It’s important to note that grenades thrown by hand are commonly referred to as hand grenades, while those fired from guns are known as rifle grenades. Rifle grenades were utilized during World War II, and modern battlefields incorporate grenade launchers as part of their arsenal.

As we enter the age of artificial intelligence (AI), the advent of various cutting-edge weapons has changed how grenades are used.

Emerging technologies can potentially revolutionize the traditional method of hand-throwing grenades, which relies on a soldier’s physical strength. There’s ongoing experimentation with a tactic that involves affixing a grenade to a drone resembling a small helicopter, allowing it to cover longer distances before launching a precision attack.

According to reports from Popular Science, the U.S. Marine Corps is actively preparing for practical deployment of this technology. They are demonstrating the use of a drone known as the Drone40, developed by the Australian defense industry company DefendTex, at a military base in North Carolina.

The Drone40, a compact drone recently unveiled, is roughly the size of an adult’s palm, resembling a small baton. It features four propellers and operates on battery power. With a flight duration of up to 60 minutes, it can achieve a maximum speed of 45 miles per hour.

Setting up an ‘Air Minefield’ with Grenade Throwing Drones

Furthermore, the Drone40 has a remote control device incorporating a satellite navigation system (GPS), allowing precise control. It boasts a maximum takeoff weight of 0.66 pounds. Its remarkable maximum travel distance of 12 miles sets it apart, a significant advancement from the limited throwing distance of hand-thrown grenades, typically a few tens of meters. This drone technology provides the military with the flexibility to employ grenades more effectively and execute operations without requiring the enemy to approach closely to our forces.

But that’s not the extent of its capabilities. The U.S. Marine Corps is exploring creating an unconventional ‘air minefield’ using this grenade-launching drone technology. Instead of directing the drone carrying the grenade toward a specific target, it remains airborne, circling over our forces’ positions, effectively creating a barrier to deter the approach of enemy aircraft or drones. While this concept is still in the experimental phase, it holds the potential to become a reality in the near future. Drones ‘ role in grenade deployment is central to this evolving paradigm of warfare.

Depending on the specific circumstances, alternative objects can be deployed instead of traditional lethal grenades. These objects may include smoke bombs, reconnaissance surveillance sensors, and electronic warfare equipment, all of which can be affixed to drones for use in offensive and defensive operations. Unlike the situation where grenades are used, and the drone is destroyed in the process, these non-lethal missions allow for the potential recovery and reuse of the drone.

Shin Jong Woo, Secretary General of the Korea Defense and Security Forum, noted, “Employing drones to launch grenades can significantly bolster the combat capabilities of small military units.” However, he also emphasized that the high cost associated with drone usage underscores the importance of ensuring accuracy and reliability in targeting specific objectives.

In 2021, the Korea Drone Innovation Association proposed integrating a grenade-throwing drone into military operations. The plan involves the development of a drone with a payload capacity of under 22 pounds, enabling it to transport weapons and travel distances of 4-5 kilometers (2.5-3.1 miles). This drone would be equipped with day and night surveillance cameras, a rangefinder, and other tools, allowing it to carry up to 10 lightweight grenades or non-lethal items such as flash bombs, Molotov cocktails, smoke or tear gas canisters. The drone would analyze parameters such as speed, altitude, and distance to release these payloads onto specified targets accurately.

Catching Drones by Throwing a Net 20-30 Feet into the Air

In 2019, a large-scale accident occurred at London’s Gatwick Airport, where drones caused many problems and posed a security risk when flying in the wrong place. According to the local media New Atlas, U.S. Army engineers are pushing to realize an idea for a product in the form of a grenade that captures drones as a countermeasure after reviewing this case. They aim to develop a grenade that captures drones.

According to the U.S. Army, an experimental 40mm grenade was invented at Picatinny Arsenal in New Jersey. Individual soldiers can shoot down rogue drones using the M320 portable grenade launcher. Heavily armed squads need to use the larger MK-19 grenade launcher. The former can target drones hundreds of yards away, while the latter can be installed at even longer distances.

It works because when the launched device gets close to the drone in the air, a servo inside the grenade releases the nose cone. This causes the net loaded on the spring to pop out from the grenade’s body. As the net spins in the air, it stretches out 20~30 feet to catch the drone. The drone caught in the net crashes to the ground. The servo is controlled by a signal from an integrated control board and can be activated remotely by someone on the ground or through an installed proximity sensor.

According to the U.S. Army, initial test results showed that throwing a net in the form of a grenade is more effective than other approaches because it does not require drone control skills. Moreover, according to experts, because one person can carry dozens of grenades, this system can also shoot down an entire swarm of drones.