True to its aeronautic roots, NASA is evaluating a new generation of supersonic airplane designs to see whether they can reduce sonic-boom levels.
Boeing and Lockheed Martin have submitted futuristic concepts that look similar to the Concorde, but aim to muffle the annoying and potentially damaging sonic boom problem.
Airplanes flying faster than sound create a cone of pressurized air molecules that extends to the ground, as NASA explains. The shockwave is noisy, but it can also cause structural damage, and in the Concorde's case, the U.S. wasn't having it. The supersonic jet never flew over land in the U.S.; sonic flights are restricted to military and research aircraft.
The new designs could make over-land travel possible, however, by using special engine or tail designs that reduce the shockwave effect.