A U.S. Air Force B-2 Spirit bomber aircraft approaches the rear of a KC-135 Stratotanker aircraft before refueling during a training mission over the Midwest, Aug. 1, 2013.
The B-2's unique design enables it to travel into enemy territory to deploy ordnance without being detected by radar. (DoD photo by Airman 1st Class John Linzmeier, U.S. Air Force). Original public domain image from Flickr