The final goal of the research is the creation of the QueSST X-Plane, or Quiet Supersonic Transport. The resulting machine would be able to avoid FAA restrictions preventing planes from going supersonic above land.
Should the plane come into existence, it may herald a new era of air transportation. At the speeds announced by NASA, travel time between London and New York would be cut down to a little over three hours.
A flight from New York to Hawaii (a better part of it overland, where currently no supersonic speeds are allowed) could be cut to 4.5 hours.
But NASA has to test the technology first. With the LBFD NASA plans to go supersonic over inhabited areas, in an attempt to gather relevant information from civilians about the perceived noise level. It will do so in a scaled-down version of the plane.
An extensive look at how NASA plans to design the new aircraft can be found at the following link.
NASA is not the only agency working on a supersonic plane design. Back in February, the Chinese Academy of Sciences presented the concept of a hypersonic airplane, capable of reaching speeds of 3,700 mph (6,000 km/h), or nearly six times the speed of sound.
Should the plane ever enter production, it would cut the normal travel time between Beijing and New York from 13 and a half hours to under two hours.