Aerial refueling, the process of passing fuel from one airplane to another in the air, is a crucial part of American military strategy, a low-profile task that makes many of the flashier components possible.
cnn s natasha bertrand is tracking this and joins us now. how is the u.s. military happening out now? reporter: yeah, kate, so a number of different military branches have been invoked to search for this vessel, including the navy, the new york air national guard and transportation command. as sara just mentioned, the navy has provided this deep submersible object essentially, a roving object, that can lift things off of the sea floor very deep inside the ocean that weigh up to 60,000 pounds, it is called the fly away deep ocean salvage system. that is going to be very key if they do actually recover this submarine and if they can ultimately try to bring it to the surface, that is going to be very instrumental in that. of course, they are still trying to figure out whether that is even possible and where this vessel even is. the navy has been in touch with the coast guard about these banging sounds and actually we just heard from a senior coast guard official earlier this