Brilliant Pebbles

Brilliant Pebbles was a space-based, kinetic-energy weapon concept formerly under development in the United States by the Ballistic Missile Defense Organization. The system envisaged approximately 4,600 small interceptors deployed in orbit, each capable of homing in on and destroying incoming hostile warheads.

Each "pebble" would be independent from any other guidance or control system. It would not need guidance from an outside source to find and intercept its target. There would...