June 6, 2020: The U.S. Army has developed a new shell for its 40mm grenade launchers. The GLAUS (Grenade Launched Unmanned Aerial System) shell is longer and heavier than the standard 40mm high-explosive shell and comes in two versions. One version launches a UAV with pop-out plastic wings, propeller and control surfaces. This version contains a video camera and communications link to the handheld controller used by the soldier who fired it. The comm-link is good for 2,000 meters and the UAV can stay in the air for 90 minutes. Each infantry fire team (4-5 troops) has one man designated a grenadier, with an M320 40mm grenade launcher attached under his assault rifle barrel. With the GLAUS UAV in the air, the team or squad (a larger unit with two fire teams) leader can scout the surrounding area from altitudes as high as 600 meters (2,000 feet).

Most small infantry UAVs, like the current 2 kg (5 pound) Raven UAVs, operate closer to the ground, usually at 100 or 200 meters altitude. Ravens are assigned to larger units like platoons (three squads) or companies (3-4 platoons). GLAUS is small enough for a patrol or small Special Forces team to carry with them and use far from friendly troops.

The second version of GLAUS is a small helicopter, with probably shorter endurance (about 30 minutes), but it can hover and is much more useful in built-up areas where you have to look into windows or alleys. If the troops find the enemy using GLAUS they can either call in an air or artillery strike or, if the enemy is close enough, use their grenade launcher to fire 40mm high-explosive grenades. If the enemy is really close and comes into view,  you can open fire using your rifles.

GLAUS is not in production yet, but the concept has been shown to work. GLAUS is also not the first guided system built for the 40mm grenade launcher. In 2015 the Pike 40mm grenade was introduced by U.S. defense contractor Raytheon. By 2019 Pike was in production and had its first customer. Here was no rush to buy Pike because of the cost. That may also hamper selling GLAUS to military organizations that have numerous essential needs and never enough money to get everything, or even most things.

The existing 40mm high explosive grenade cartridge is about 100mm (4 inches) long and weighs about 545 gr (19 ounces). The 40mm shell which leaves the launcher tube is about 43mm (1.9 inches) long, weighs about 250 gr (nine ounces) and can be fired out to about 400 meters. An experienced grenadier could only fire these grenades accurately at targets as far as 200 meters distant.

The Pike is a longer and heavier 40mm shell. Pike is 430mm (16.8 inches) long and weighs 770 gr (25.6 ounces). While the Pike warhead is about twice as powerful as the unguided 40mm grenade, most of the additional bulk and weight of the Pike is taken up by the laser detector in the nose, a microcomputer, four pop-out fins and electronic and mechanical components to operate the fins to guide the Pike to a target up to 2,000 meters away. The Pike homes in on laser light reflected from the target, which is “painted” by a laser designator that looks like a pistol. Normally Pike is operated by a two-man team. One man is the grenadier, firing the Pike from a common one round 40mm grenade launcher. The second man, the spotter, points the laser designator and holds it on the target until the Pike reaches it (after about 20 seconds). Actually, one person could operate the Pike because at max range Pike will be in flight for about 15 seconds before it can detect the laser light reflected off the target by the handheld laser designator. So one person could fire the Pike then pick up the laser designator, turn it on and designate the target.

Pike will land within five meters of the laser light reflected off the target. The warhead is more powerful than hand grenades so Pike will kill or injure anyone within ten meters (32 feet) of the aim point. Pike obtains its long range by using a small explosive charge to propel Pike about three meters into the air before a smokeless rocket motor takes over giving it the momentum needed to carry it at least 2,000 meters.

As of 2019, only one customer has been found for Pike. The Canadian Army bought some for its special operations troops. The major problem with Pike is the cost of each round. The standard 40mm grenade fired by infantry costs about $30 each. The Pike manufacturer (Raytheon) has not made public the cost of each round but, given the cost of other small laser-guided missiles (like the 70mm APKWS), each Pike probably costs at least $3,000 and probably two or three times that. It could be useful for special operations troops but for most infantry, there are plenty of other guided munitions available, many of them cheaper and more destructive than Pike.

Meanwhile, American troops already have a very lightweight UAV, but not as light and portable as GLAUS or Pike. The Switchblade is a small UAV fired from its shipping container. Switchblade was sent to Afghanistan in 2009 for secret field testing. This was very successful and the troops demanded more, and more, and more. Switchblade completed development in 2009 and was initially thought useful only for mainly special operations troops. In 2011, after a year of successful field testing, the army ordered over a hundred Switchblade UAVs for troop use and last year ordered more as regular infantry units got their hands on it and demanded more.

By 2012 the U.S. Army and Marine Corps had ordered hundreds of Switchblades because the combat zone testing proved so successful. Switchblade was developed for the army but the marines apparently noted the success that soldiers and SOCOM (Special Operations Command) had with this system and ordered them as well. Switchblade was very popular with troops in Afghanistan and with SOCOM in all sorts of places they won’t discuss in detail. Switchblade is still used and thousands have been ordered and many of them used. There have been several upgrades

Switchblade is a one kilogram (2.2 pound) expendable (used only once) UAV that can be equipped with explosives. The Switchblade is launched from its shipping and storage tube, at which point wings flip out, a battery-powered propeller starts spinning and a vidcam begins broadcasting images to the controller. The Switchblade is operated using the same controller as the larger (two kg) Raven UAV. A complete Switchblade system (missile, container, and controller) weighs 5.5 kg (12.1 pounds).

Moving at up to a kilometer a minute, the Switchblade can stay in the air for 20-40 minutes, depending on whether or not it is armed with explosives. Switchblade can operate up to ten kilometers from the operator. The armed version can be flown to a target and detonated, having about the same explosive effect as a hand grenade. Thus, Switchblade enables ground troops to get at an enemy taking cover in a hard to see location.

Technically a guided missile, the use of Switchblade as a reconnaissance tool encouraged developers to refer to it as a UAV. But because of the warhead option, and its slow speed, Switchblade also functions like a rather small cruise missile. The troops were particularly enthusiastic about the armed version because it allowed them to easily take out snipers or a few bad guys in a compound full of civilians. It was these sorts of situations that apparently led to systems like the recently introduced Israeli Firefly.

Switchblade has been so successful that the army ordered a Switchblade 2.0. The new version is also called LMAMS (Lethal Miniature Aerial Munition System). It is heavier with up to 30 minutes endurance and a 9 kilometer range. The sensor must have night vision and be stabilized. It must also be able to lock onto a target and track it. In 2018

In 2019 an Israeli firm introduced the Firefly, a loitering munition UAV, which is portable enough for infantry to carry and continually reuse. There is also the option to replace one of the two batteries with an explosive warhead and turn Firefly into a guided weapon. Another major advantage of Firefly is that it operates like a helicopter, not a fixed-wing aircraft. Being able to hover is a major advantage for loitering munitions used by infantry. What Firefly seems to have done is address all (or most) of the user criticisms of earlier lightweight loitering munition systems.

Firefly was developed by Rafael, the same firm that developed and builds the Spike family of ATGMs (anti-tank guided missiles). Much of the tech in Firefly was based on what is already used in Spike systems. In particular, Firefly has a guidance system that can track and attack a moving target. This can be critical for infantry using such a weapon because these targets are elusive in the first place and, without a UAV, the infantry would not have spotted dangers like snipers or moving troops at all.

Firefly is a dual rotor miniature helicopter and those dual (on top of each other) rotors make it stable in winds that would make a similar-sized fixed-wing or quad-copter UAV unusable. The .4 kg (one pound) warhead replaces the second battery to halve the normal 30 minutes of flight time. The operator uses a small tablet device that is mostly a touch screen and a Firefly controller. Firefly can be controlled up to 500 meters in a built-up (or forested) area or up to 1,500 meters in line-of-sight (nothing between Firefly and operator) mode. Firefly returns to the operator if the control signal is lost. The operator can press an icon on the screen to get Firefly to return immediately, abort an attack or carry out a high speed (19 meters/62 feet a second) attack on a target. The target can be moving, as in a sniper changing firing positions out of sight of the operator. This is accomplished using the ability of the Firefly guidance system to remember the shape of a target and follow it. The Firefly warhead would be most often used against troublesome targets like snipers or hidden machine-guns. Even without the warhead Firefly would be able to locate such lethal adversaries and enable the infantry to avoid them. Firefly can also be launched and operated from a moving vehicle.

The big advantage Firefly has over GLAUS and Switchblade is reusability. Carry one Firefly and just use it as a UAV for a dozen or more times. Because of the relative simplicity of the Firefly compared to GLAUS, Pike or Switchblade, it is probably cheaper. Add in the reusability and Firefly is definitely cheaper.