Washington's European Phased Adaptive Approach involves incremental increases in ballistic missile defense systems on the Continent. The original plan called for deployment of shorter- and medium-range interceptors in the first three phases and longer-range interceptors in the fourth phase. The first phase, which involved radar stations in Turkey and ship-based missile defense systems in the Mediterranean, has already been implemented. During the second and third phases, more-advanced interceptors capable of targeting short- and intermediate-range ballistic missiles would be deployed to Romania by 2015 and Poland by 2018. In the fourth phase, the longer-range SM-3 Block IIB missiles would be deployed in Romania and Poland around 2022. Compared to its predecessors in the Standard Missile-3 line, the SM-3 Block IIB would have enhanced seeking capabilities and a more powerful booster, allowing it to reach speeds of 5.5 kilometers per second (about 3.4 miles per second).