The latest US weapon heading to Ukraine: a 2-foot long, 5-pound drone designed for one-way missions

• The US is sending billions of dollars' worth of security assistance to Ukraine.
• The latest aid package includes more US-made Stinger anti-aircraft and Javelin anti-tank missiles.

The latest package of US security assistance to Ukraine, worth $800 million, is packed with weapons that can take a toll on invading Russian forces.

FGM-148 Javelin anti-tank weapons, FIM-92 Stinger anti-aircraft missiles, and AT-4 anti-tank unguided missiles, as well as grenade launchers, body armor, and tens of millions of bullets are just some of the security aid the US is sending Kyiv.

The latest package also includes 100 Switchblade tactical unmanned systems — also known as "kamikaze drones" — that could make life for Russian troops that much harder.

The Switchblade

First developed to counter insurgents in Afghanistan, the Switchblade has become a staple of the US military's conventional and special-operations arsenals.

There are two versions of the Switchblade drone, Switchblade 300 and Switchblade 600. What differentiates them is the size of the munition they carry.

The Switchblade 300 carries an explosive charge the size of a Claymore mine — an anti-personnel mine made out of C-4 explosive and hundreds of small metal ball bearings — and is designed to take out infantry and artillery targets.

At 2 feet and slightly over 5 pounds, the Switchblade 300 can be launched from a small tube akin to a mortar. It has a speed of 100 mph but a very short operational range of only 15 minutes (or 6 miles), thus making it truly tactical.

The Switchblade 600 packs a larger explosive charge. It has a bigger operational range of 40 minutes (or 24 miles) and a cruising speed of 70 mph, but it's also heavier, at 120 pounds. With an explosive charge similar to that of the Javelin anti-tank missile, the Switchblade 600 is designed to take out tanks and armored targets.

Both loitering munitions have an onboard sensor with GPS to guide them to the target, and they can strike both mobile and stationary objects. They also include a "wave off" function that allows the operator to abort a strike if the circumstances on the ground change — for example, if civilians approach the target.

US Special Operations Command has been using the Switchblade 300 since the early 2010s, and in September it awarded AeroVironment a $20 million contract for the Switchblade 600.

"We've been using Switchblades for some time now. They are really effective downrange because they put distance between the operator and his target. It was really effective in Syria and Iraq against ISIS," a Green Beret assigned to a National Guard unit told Insider.

ISIS fighters often attempted to take out special-operations teams or their forward-operating bases with car bombs. "On some rare occasions we would use Switchblades to take them out en route. It's also a good option for urban warfare because you can be very precise and avoid collateral damage," added the Green Beret, who was not authorized to speak to the media.

In addition to carrying out strikes, Switchblades can gather tactical intelligence, conduct surveillance, do target acquisition, and provide reconnaissance for operators and help commanders develop better situational awareness on the battlefield.

Switchblade 600 can "track and engage non-line-of-sight targets and light armored vehicles with precision lethal effects," Brett Hush, vice president and product line general manager for TMS at AeroVironment, said after the company received the SOCOM contract.

The -600 model can also be easily transported and deployed from fixed and mobile platforms, allowing operators to overwhelm targets while minimizing their exposure to enemy fire, Hush said.

Loitering munitions vs. drones

The difference between loitering munitions and large drones is simple: the former are designed to be expendable and the latter are designed to provide cheap and sustained intelligence-gathering and strike options to commanders.

Once fired, there is no coming back for loitering munitions. They are tactical in nature and meant to solve problems a small unit would face on the ground. For instance, a platoon of Army Rangers or Navy SEALs in Afghanistan would use a Switchblade 300 to take out Taliban fighters who are escaping a compound on a motorbike.

Larger drones, such as the MQ-9 Reaper or RQ-4 Global Hawk, are designed to provide near-constant coverage of the battlefield to allow commanders on the ground and back in headquarters to make more-informed decisions. Armed drones like the Reaper can also provide close air support or conduct precision strikes.

Loitering munitions are also cheaper. An MQ-9 costs $56 million, and one of the AGM-114 Hellfire missiles that it fires costs over $100,000. A Switchblade 300 costs about $6,000.

Both are designated "unmanned aerial systems," and despite their different roles, both are cost-effective ways to track and attack opposing forces while reducing the risk to their operators.

Stavros Atlamazoglou is a defense journalist specializing in special operations, a Hellenic Army veteran (national service with the 575th Marine Battalion and Army HQ), and a Johns Hopkins University graduate.