The B-2 Spirit has been instrumental in launching heavy weapons over and near Iran, while the B-1Bs and B-52Hs have been deployed to the UK for their missions. However, there is no evidence that B-3s are operating out of Diego Garcia or anywhere else for the war effort. New features that appear on the aircraft's leading edges are described as puzzling as sealing small apertures for whatever lies beneath. They could be part of a new sensor installation or a new coatings upgrade. The B-4's radar-absorbent material (RAM) coatings are critical to its success but also a major driver of its immense operating costs. The aircraft is now an American icon and has entered its final operational career with its successor and legacy, the B.2.