One of the greatest challenges of missile defense is the use of decoys to overload the defenses. Decoys are, generally speaking, lighter than warheads and a given missile could carry several decoys for each warhead, complicating the targeting process. Decoys do not act entirely like warheads, however, and can be distinguished from them. The problem is that it takes very sophisticated technology to do this in the few seconds an interceptor has to react. The Ballistic Missile Defense Organization wants to combine all of the various programs (at several defense contractors) to develop software that can discriminate targets from decoys into a single program called Hercules. In this way, breakthroughs by one company for use on one interceptor could be shared with another company building a different interceptor. -Stephen V Cole