The Department of Homeland Security is on the verge of awarding the biggest contract in its young history for an elaborate system that could cost as much as $15 billion and employ a network of databases to track visitors to the United States long before they arrive. The contract, which will probably be awarded in coming days to one of three final bidders, is already generating considerable interest, as federal officials try to improve significantly their ability to monitor those who enter at more than 300 border-crossing checkpoints by land, sea and air, where they are going and whether they pose a terrorist threat. But with that interest have come questions–both logistical and philosophical–from Congressional investigators and outside experts. Will a company based outside the United States, in Bermuda, get the megacontract? How much will it end up costing? What about the privacy concerns of foreign visitors? And most critical, for all the high-end concepts and higher expectations, can the system really work? Full Story