The U.S. Army has flown it's Shadow and Hunter UAVs some 35,000 hours over the last six years. But a third of that usage has occurred this year in Iraq. As a result of all that experience, the army is experiments with using UAVs for some new missions. The new Vigilante UAV is being outfitted to deliver critical supplies to small groups of isolated troops (usually Special Forces). Air drops of 500 pounds (or more) of supplies per sortie could be carried out. The same UAVs that can carry missiles can also carry special supply containers. Things like medical supplies, or batteries, could be sent in at night without attracting the attention of hostile forces in the area. Some UAVs are also being equipped with sensors for detecting chemical, nuclear and biological weapons. UAVs so equipped can quickly check out a large area, or continuously patrol a route U.S. troops plan to take.