It is the largest, fastest, and most intelligent projectile available to the US Army. Despite this you probably never heard of it nor the Army National Guard Soldiers who "pull the lanyard." If you think a 155mm howitzer shell is big, the M21 rifle is accurate, the MLRS can fire over a long distance, or that the PATRIOT air defense system is sophisticated, you are correct on all accounts.
There is one system operated by the Army National Guard however, that dwarfs any of its nearest competitors. That system is the Groundbased Midcourse Defense system and it has been operational for more than a decade with Army National Guard Soldiers from Colorado, Alaska, and California's 100th Missile Defense Brigade.
The tip of the spear for the GMD system is its Groundbased Interceptor, or simply "GBI." While it may not be the most awe-inspiring name for a defensive weapon system, its performance in conjunction with its fire control system will certainly leave you in awe. The GMD system is the ultimate "smart weapon."