The U.S. Army recently ordered another 110 JPADSs (Joint Precision Airdrop System), which cost $273,000 each. JPADS kits are attached to pallets of supplies to provide GPS and mechanical controls that guide the direction of the descending parachute for pinpoint landings. Before the parachute is used, the pallets first release a parafoil (a parachute that can be controlled in such a way that the user can gain altitude and travel over long distances) and the pallet descends at about 44 meters a second (from an altitude of about 6,000 meters, safely away from any ground fire), guided towards the landing point. When a few hundred meters over the programmed drop zone the parafoil is released and the parachute deploys, bringing the pallet (with up to five tons of supplies) down within a hundred meters of the programmed landing point. A single cargo aircraft can deliver up to 40 pallets this way heading for many different landing zones. JPADS has release point information (calculated using current weather conditions) sent to the aircraft, along with GPS landing coordinates for the pallets. This GPS data is transmitted to each pallet via a wi-fi type system.
Since 2007 American forces (air force and army) have been using such high altitude guided cargo parachute systems, mainly for drops in Afghanistan. These guided parachutes have also been used for relief operations, in Afghanistan and Haiti, where the landing zone was small or the weather bad. In 2013 some were used in Mali.
Systems like JPADS were been developed quite recently (since 2000) from earlier, less capable and reliable precision para-drop systems. All rely on GPS to give accurate landing information and easily manipulated parafoils to provide the maneuverability. The aircrews find it fascinating to push a bunch of pallets out and then watch as they form into "flocks" and head off for their various drop zones. For the troops on the ground, it's a convenient way to get supplies, no matter where they are out in the boondocks.
Before the development of GPS guided air drops, a large percentage of air dropped supplies were lost, either by falling into enemy hands or into things that destroyed them (especially water). With the new delivery systems it's even possible to do night drops if you don't want to alert nearby enemy troops.
While expensive, systems like JPADS are reusable and most are recovered, checked over and repaired if necessary and used again dozens of times. Most of these systems are now sold to foreign customers.