The new US weapon, the Small Smart Bomb, has completed its wind-tunnel tests and will make its first live drops later this year. The SSB weighs only 250 pounds (and has only 50 pounds of high explosive inside), but can penetrate 1.8m of reinforced concrete. The US plans to use it (when it enters service in 2007) to destroy those targets which are well protected but which do not require a lot of destructive power. Hardened aircraft shelters, for example, were routinely attacked in the Gulf War with 1,000-pound or 2,000-pound weapons, which not only penetrated the bunker but reduced the insides to churned scrap. The smaller bomb will destroy anything inside a bunker or hardened hangar without actually tearing it into playing-card-sized pieces. By using smaller bombs, tactical aircraft could attack more targets on a single mission. The F-22 Raptor could even carry such bombs internally, and other stealthy aircraft could carry larger numbers of weapons.--Stephen V Cole