Originally posted by FUNKED1
Neptune was the airborne operation.
Sorry, but incorrect. Neptune was indeed the naval portion of the invasion. It has been misreported that Neptune was the codeword was for the airborne operation and there is a good reason for this.
There is a lot more that goes into airborne operations than just jumping out of the plane. Neptune was code word used for setting Overlord into motion. The ships took longer to get to their targets, their were more of them to manage, etc, etc. Additionally, once all those ships were fully commited, you just could not turn them around. There were security issues, safety concerns, etc, etc.
At the time the ships started moving, the paratroopers started getting geared up for their jump at around (or shortly after) midnight. There wer last minute briefings, intel updates, equipment checks and inspections, etc. Then, just loading up on the planes and gliders. It is a very time consuming process.
When the "Neptune" code word was given, it also set the airborne operation into motion, which is the reason for the confusion. As pointed out, Neptune was the mythical god of the sea and so, the naval portion of the invasion was named Neptune.
I believe Cornelius Ryan's book, the Longest Day, makes this clear as well. If not, there is a vast wealth of resources on the subject.