Description

The video on the right shows a prototype.

In 2008, Lockheed Martin discreetly tested a forward-looking missile-defense concept known as the Multiple Kill Vehicle (MKV). Instead of a single interceptor, MKV proposed releasing several small, autonomous kill vehicles in space, each able to track and destroy individual warheads or decoys.

I know the vehicle doesn't demonstrate the powerful propulsion that keeps the prototype aloft, but if that was in 2008, perhaps an improved model exists now.