Skyguard

In this artist's rendering, defense contractor Northrop Grumman shows how its Skyguard system might work to defend airports against missile or artillery attacks. The company says the high-powered laser system could in essence create a shield with a five-kilometer radius (20 kilometers against shoulder-fired missiles)--at a cost of tens of millions of dollars.

The ground-based Skyguard is derived from the Tactical High Energy Laser (THEL) system that the company developed for the U.S. Army and Israel's defense ministry. Israel has reportedly used a mobile version of the THEL system to shoot down Katyusha rockets. To see photos of work being done on airborne laser defense systems, click here.