DarkStar, a secretive and stealthy UAV development project, was cancelled in 1999 when the prototype proved to be unreliable in flight. It turns out that the project was not scrapped completely. The U.S. Air Force admitted that an upgraded, and much more reliable (in flight) version of DarkStar was used successfully over Iraq. The "DarkStar II" (for want of a better name) is said to have the same odd (but stealthy) shape of the original DarkStar, but a bit larger. It carries a sensor load similar to the Global Hawk, but only can stay in the air for about eight hours. There are supposed to be two of these UAVs, and at least one flew from an air base in Qatar. The section of the base where the UAV was stored was off limits to journalists. Most other pilots did not know about DarkStar II flying in the area, and this caused some consternation when some U-2 pilots, who flew at the same high altitudes as the DarkStar II, saw the aircraft and could not identify it.