The biggest military news of the year revolved around the chaotic and dramatic US evacuation from Afghanistan as the Taliban took over the country in August. 

While that series of historic events rightfully captured the biggest headlines, developments large and small in the military technology space also made news throughout 2021. Some of the more groundbreaking and revolutionary innovations earned Best of What’s New awards from Popular Science in both the Aerospace and Security categories, including a drone that can refuel Naval fighter jets, an AI-powered system called Skyborg that can fly uncrewed aircraft, and an anti-drone system known as THOR.

But many more military aircraft, vehicles, robots, gadgets, and events made news over the past 12 months. These are some of the important, fascinating, noteworthy, or just plain neat developments worth taking a look back at.  

On the ground

Microsoft inked an enormous, multi-billion-dollar deal to deliver high-tech augmented reality goggles for the US Army. The gadget is based on Microsoft’s HoloLens, although the Army refers to it as the Integrated Visual Augmentation System, or IVAS. The devices are a head-up display with night-vision tech and more, and while they promise to be a futuristic way for soldiers to receive information and see the battlefield, they’ve been delayed due to an issue related to the scope of its field of view. We’ll know more about how these devices are doing next year. 

Down at Tyndall Air Force Base in Florida, mechanical dogs from Ghost Robotics joined the security team to patrol the base in March. The legged bots can hit a top speed of just 4.5 mph and function as a “mobile sensor platform,” as one base official described them, meaning they can feed information back to humans. 

In June, US Marines experimented with a vehicle called the EMAV, a robotic, tank-like contraption that can act as both a stretcher to carry off an injured person or even execute tasks like launch weapons. Each vehicle weighs 7,000 pounds, and that’s before anything is mounted on it. Marines can control it via a tablet and it can fit inside a V-22 Osprey aircraft for transport. 

In the air 

While robots help out on land, up in the sky their winged cousins conduct their own missions. In October, DARPA demonstrated an eye-catching stunt: It used a C-130 cargo aircraft to grab a drone out of the sky and pull it into the mothership. The idea behind the program, called Gremlins, is that snagging the drones and bringing them into a cargo plane mid-air is a way to recover and reuse these aerial assets. In other DARPA news, the agency tested out a hypersonic missile in September—the weapon concept it demonstrated went faster than Mach 5. 

Drones and other uncrewed vehicles, like hypersonic weapons, are certainly not the only military innovations to zoom through the skies. In April, the Air Force took the wraps off its latest fighter jet and announced its official name, the F-15EX Eagle II. It’s the most modern US version of an aircraft that dates back to the 1960s and 70s and was first created to be an air-to-air dominance machine. Read a deep dive on the new aircraft here

Russia, meanwhile, unveiled its own new fighter jet, called Checkmate. Unlike the F-15EX, this new jet is stealthy, and is most frequently compared to the F-35 but promises to be less expensive. The Drive, a sibling website to PopSci, has more on the plane’s progress. 

Helicopters are some of the most dynamic and maneuverable flying machines around, and May of this year marked the 10-year anniversary of the Navy SEAL raid on Osama bin Laden in Pakistan. Popular Science took a look back at what we know about the stealth helicopters that were part of the covert mission from Afghanistan into neighboring Pakistan in 2011. 

And in other helicopter news, we tagged along in May on a training mission with the US Coast Guard in a MH-60T helicopter to see how they train for hoist rescues at sea. The dramatic, dynamic process involved a brave “duck” being lowered into the frothy waters below the chopper off the coast of Cape Cod, Massachusetts. 

In the water

In the watery parts of the world, militaries cruise the oceans—in their depths and on their surfaces. In September, we got a glimpse of an uncrewed ship called the USV Ranger launching a missile. The program the ship is part of is known as Ghost Fleet Overlord. 

And over the summer, the Navy invested in underwater gliders that will be able to sense the water conditions below the surface, noticing factors like temperature or electrical connectivity; these uncrewed robotic submersibles need to be able to stay down for as long as 90 days at a depths of some 3,300 feet. 

Back up on the surface, the Navy has been trying out other robotic boats as well—deploying uncrewed vessels called Saildrone and MANTIS. After all, who needs humans when robots can do all the exploring for you?