From my understanding, faster speed = high fuel consumption. During the days of the Concorde, high fuel consumption wasn't seen as a problem. Today, consumers and the market are more focused on things that, at least, appear to be good for the environment.
Exceeding 660 miles per hour above sea level creates the boom. Once an aircraft breaks the sound barrier, it creats an extended boom that is heard by anyone who is near the supersonic craft. So it isn't just one single boom -- it's continuous as long as the craft is exceeding the the sound barrier, even if those on the ground experience it as a single boom. So, on a flight from L.A. to N.Y that exceeds the sound barrier, everyone on the ground between the two cities would experience the window-shaking (and sometimes window-breaking) boom.
NASA, however, is looking at strategies for taking the boom out of high speed aircraft:
OK, that explains a lot. When I read the article -- which didn't address sonic booms -- I wondered whether the small size of the craft negated the sonic booms. Maybe they just take the boom over the ocean and move on.
Yes, Rich, I also saw that CNN article, andI too was surprised. I was under the (perhaps mistaken) impression that speeds exceeding 600 mph would cause sonic booms that would be unacceptable to residents. And thus, there was a wall against faster speeds. Yet at 4,500 mph, why no sonic booms?
What's getting in the way of speed? Is it just cost or is it, like usual, government regulation? Even in its heyday, the Concorde was only allowed to fly at its advertised speed over open ocean. I think it was "illegal" for them to fly a New York to LA route at those speeds.
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