NASA has plans to make commercial supersonic air travel a reality--again.
The space agency announced last week that it is working on a design for a new aircraft called the X-Plane, which could fly passengers from New York to Los Angeles in as little as 2.5 hours. The key to resurrecting commercial air travel that can reach speeds of Mach 2 (roughly 1,350 miles per hour) is to do so quietly, as the loud, supersonic boom the now-retired Concorde used to produce is what led to a global ban on supersonic planes.
"The trick to making airplanes quiet is to change the way the air flows around the airplane," Juan Jose Alonso, a Stanford professor of aeronautics and astronautics, told Wired. Planes that break the sound barrier by reaching more than 786 miles per hour generate shock waves that eventually produce a distinct double "boom" sound. The noise created by the Concorde was measured at 106 decibels, but NASA thinks a redesign could get that down to 65 or 70 decibels.
Minimizing the sound of the shock waves could involve eliminating the cockpit window entirely, replacing it with a pointy-tipped fuselage, and putting the pilots in the middle of the plane. This would require video cameras for visual navigation.
Lockheed Martin is the company ironing out the details, having won a $20 million contract from NASA to design the blueprints. A working prototype would cost at least $300 million, and could be in the air as soon as 2019, according to NASA.
Among the challenges facing the effort to make the X-Plane a reality are the higher cost of fuel, as supersonic travel requires between two and three times as much fuel as conventional airplanes. The skinny shape of the plane could also prevent each flight from carrying enough passengers to make the aircraft economically viable.
Still, Peter Coen, a supersonic project manager at NASA Langley says that bringing back supersonic commercial air travel is entirely doable. He and his colleagues are experimenting with composite materials that could help produce a lighter airframe and engine specifications that could allow the X-Plane to use a third of the fuel required by the Concorde, he told Wired. "We are chipping away at the efficiency gap between subsonic and supersonic aircraft," he said.