Quiet, Efficient Supersonics Within Sight?

The trick is in the shaping of the airframe to tailor the shockwaves so that they produce a sinusoidal pressure signature at the ground, rather than the abrupt N-wave shape of a traditional "double-bang" sonic boom. Instead of powerful bow and aft shockwaves, the aim is to generate lots of smaller shocks along the airframe that attenuate more quickly as they travel through the atmosphere. Boeing's model (above) shows the result of all that subtle shaping.

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