Washington Dulles airport began using Airport Surface Detection Equipment, Model X (ASDE-X) this month, giving controllers in the tower a more complete picture of activity on the ground. FAA said the airport is now the 12th U.S. airport to use the satellite-based technology. "ASDE-X is light years ahead of the old system," said Dulles Tower's Assistant Air Traffic Manager Charlotte Happle. "The accuracy is very good and it helps us with our ground movements, especially during times when visibility is low." Originally intended to be installed at 25 airports when the FAA awarded the ASDE-X contract to Sensis Corp., Syracuse, N.Y., in October 2000, the agency later expanded the project to include 35 airports. FAA estimates it will cost over $806 million to procure, deploy and operate ASDE-X over a 30-year life cycle.