The Joint Direct Attack Munition (JDAM) is a guidance kit that converts existing unguided free-fall bombs into precision-guided smart munitions. By adding a new tail section containing a global positioning system (GPS)/inertial navigation system (INS) guidance control unit to existing inventories of Mk-83 and BLU-110 1,000-pound bombs, and the Mk-84 and BLU-109 2,000-pound bombs, the cost-effective JDAM will dramatically improve the accuracy of precision strike munitions in adverse weather. JDAM can be dropped by an aircraft from up to 15 miles from the target. Updates from GPS satellites will help guide the bomb to the target.