from Popular Mechanics:
The U.S. Is Sending Deadly Javelin Missiles to Ukraine
The Javelin missile was designed in the late 1980s and early ’90s to be the standard U.S. medium-range anti-tank missile. Javelin was meant to replace the awful Cold War-era Dragon anti-tank missile, which was heavy, unreliable and generally despised by American troops. Javelin, on the other hand, has been a tremendous success and is one of the most widely used anti-tank missiles of the post-Cold War era.
U.S. Marines carry the Javelin missile system to a firing position. The marine on the left carries the Command Launch Unit (CLU), while the marine on the right carries the missile canister.
Javelin is a two-part system comprised of a reusable Command Launch Unit (CLU) and disposable missile canister. The CLU attaches to the missile canister and provides a 4x day viewer and a magnified thermal imager. Once the gunner identifies an enemy tank, the gunner locks onto the target and launches the missile. The missile can hit tanks, armored vehicles, fortifications, and even helicopters at ranges of up to 2,733 yards.
The Javelin missile speeds towards its target, zeroing in by constantly comparing its field of view to the original image of the tank it locked onto. The missile is entirely self-homing—a “fire and forget” system that allows the missile crew to displace to a new firing position while the missile is in the air. Javelin can engage an enemy tank at eye level or using a “top attack” mode in which it flies upward and then streaks back down, smashing down into the thinly armored spaces on a tank’s turret roof and top of the hull. Javelin has two warheads, a smaller one to detonate a tank’s explosive reactive armor and a larger one to follow up and punch through the armor itself.