The bombs are called Joint Direct Attack Munition, or JDAM, and like laser-guided bombs used in the Persian Gulf War and subsequent conflicts, JDAMs can be steered toward targets. Conventional, or so-called dumb bombs, simply drop to the ground. Once released from the aircraft, a JDAM receives data from the GPS satellites to locate where the bomb is relative to the target coordinates.
Small control fins on the tail of the bomb adjust to guide it as it falls.
Laser-guided bombs require bomber crews to fly low enough to identify the target and illuminate it with a laser before dropping the bomb. JDAMs don't require the bomber crew to locate the target. And since pilots don't need to see the target at all, they can fly their planes at higher, safer altitudes. What's more, since JDAMs are guided by invisible satellite signals, they can be used in any type of weather. What's more, since JDAMs rely on signals from far away satellites, enemies could develop a jammer that would spoof the GPS signals and cause the bomb to go awry, he said.