GPS-guided parachutes deliver supplies to soldiers in remote areas

Mountainous terrain and enemy threats in Afghanistan have pushed the Air Force to develop a kite-like GPS-guided system to deliver cargo to deployed troops, a commander told a House panel on Thursday.

The Air Force has used pilot-controlled aircraft to drop a load of supplies that can guide itself to a specific location. But the Army Soldier Research, Development and Engineering Center in Natick, Mass., has kicked off a program to use unmanned aerial vehicles to perform the same type of mission.

Air Force Gen. Duncan McNabb, commander of the U.S. Transportation Command, told a hearing of the House Armed Services Committee that the Joint Precision Airdrop System (JPADS) helped deliver more than 3 million pounds of cargo to troops working in rough terrain in Afghanistan in 2009.

JPADS uses an onboard GPS system to help guide a parafoil -- a steerable canopy parachute -- to deliver supplies that can weigh as much as 30,000 pounds, according to a briefing that Maj. Erin Staine-Pyne presented in 2009. The system has improved the accuracy of airdrops by 60 percent.

To further refine the accuracy of deliveries, the Air Force drops a 3-pound sensor from the aircraft, typically a C-130, before the drop to measure wind speed. The sensors, called dropsondes, transmit information to a laptop computer on the aircraft, which the crew uses to determine the most accurate release point for the parafoil and its load.

The Army's research center developed the original JPADS system for manned aircraft, and has begun building a system for UAVs such as the Predator to airdrop supplies using the parafoil system. In a paper presented at the American Institute of Aeronautics and Astronautics in May 2009, Richard Benney, technical director for JPADS, said these systems can carry a 400-pound payload in a pod strapped to the belly of a UAV.

The pod uses a GPS guidance system and computer, which before releasing its cargo is updated with information transmitted from a remote planning system via the iridium satellite system. The UAV then transmits the information to the pod guidance system using a wireless link.

While cargo drops in Afghanistan now focus on supplies such as food and ammunition, Benney said the Army also is developing smart parafoil systems to deliver medical supplies.