As you might expect, several issues face the implementation of the tech -- like the fact that the sub would have to be launched at a high rate of speed to maintain the requisite air bubble. Traditional steering methods (read: rudders) wouldn't work inside the air pocket either, as they wouldn't have water to push back on. However, to combat the two conundrums, researchers say allowing a vessel to constantly "shower" a liquid membrane on its surface would reduce drag until it gets up to speed. From there, the same membrane creates the supercavitation and controlling the friction on it would aid navigation. Even with those issues under control, a rocket engine with a range that would enable such long trips still needs to be developed. So for now, you'll have to stick to spending several hours flying the friendly skies.

Update: The headline of this story has been updated to reflect that the research into the supersonic tech is on-going and theoretical. It wasn't intended to be misleading, but I can certainly see how it was.

[Image credit: Sam Yeh/AFP/Getty Images]