I can still remember way back in WW2 when my big brother joined the U.S. Army Air Forces. Then, in 1947, President Truman created the Air Force as separate from the Army. In my two wartime hitches in the U.S. Navy, that sea-going swabby service never changed its name, and is still USN today.
However, even way back then, there was a hint of what may happen now with the new branch. I recall serving on ship and shore with many very spaced-out Navy astronuts, ranging from apprentice seamen to admirals. Also, will the new service theme song go something like: Off we go into the space race yonder?