The base in Deveselu will be the first to feature the Aegis Ashore ballistic missile defense system, a land-based version of the sophisticated radar tracking system installed on U.S. warships since 2004. Scheduled to become operational by the end of next year, the base — which is housed within a larger Romanian military installation — will be staffed by several hundred U.S. military, civilian and contract employees. A second site, in Poland, is scheduled to become operational by 2018.