Re: NASA boom mitigation
Somehow posting on the mobe ate half what I sent.
Yes, the US Gov pissed off the public by running fighters low over cities, but they also did useful research with the cancelled XB-70 before retiring it, flying it on a large range of flight profiles and heights over Edwards for months and measuring the boom patterns as well as similar tests in the midwest.
The Valkerie was huge plane and a spectacularly loud boomer (much louder than it should have been for its size) thanks to the Waverider layout. It gave a lot of valuable data and showed that 1950s-60s designs were simply too loud to be tolerable even at 50-60,000 feet over land - which was quickly proven on those Concorde flights into Bahrain/Singapore.
If Boeing hadn't been set a target by the US Government of building something significantly faster than Concorde they might have succeeded. Bigger and more range was relatively easy but the extra speed meant the thing got so hot that it needed new materials which simply weren't available.
Even Concorde was pushing normal materials limits and you can't build a civil transport that leaks fuel like a plastic bag full of nails when it's on the tarmac like the SR71s did (not to mention the fun they had acquiring Soviet titanium). No matter for Boeing, as the entire enterprise was funded by Uncle Sam and the backstop program turned into a roaring commercial success. If the SST had succeeded, we may have never seen low cost mass transport from the 747 (which at its core is a 707 scaled up 50% for freight work, with an elevated flight deck to both protect the pilots from shifting cargo and allow a nose door to be fitted without disconnecting/reconnecting/recalibrating all the flight controls every time it's opened. Everything else is evolution)
Without some magic way of reducing friction, supersonic doesn't gain much for your money unless you're going at least 6-9 hours conventionally and then you really want hypersonic or skipping, else fuel will be 90% of your MTOW. Reaction Engines might still have their day for 4 hour London-Sydney vomit rides.
As for booms - there's no way the public will put up with more than a even a couple of quiet booms a day - particularly in quieter areas. Making them unnoticable in urban areas isn't as important as making them unnoticeable when people are in the suburbs or rural locations. (In a quiet location you can hear a 747-400 flying past at 35,000 feet, as the daily transpolar flights to Argentina did over my parents place when I was in my 20s. It can't be any louder than that). I heard Concorde boom once. You could put up with that once a day on a predictable pattern but every other flight at effectively random intervals would trigger murderous rampages in a lot of people (chinese water torture...)
Biting the hand that feeds IT
