As the troubled history of the Concorde (and its lesser Soviet counterpart, the Tupolev Tu-144) showed, supersonic air travel depends on overcoming a lot of obstacles, from the pesky sonic boom to high cost, safety issues and insatiable fuel consumption.

 

So airlines have given up the quest to reduce travel times, and have focused on fitting more passengers into their planes for less. These days, the closest anyone who isn’t an Air Force pilot or astronaut can get to Mach III is using a Gillette razor.

But the dream of jetting from New York to Tokyo in under three hours hasn’t been abandoned. Among travelers, especially the wealthy, there’s still demand for shorter flight times, especially since air travel has become so unpleasant in recent years. And there’s a young but growing market to meet that demand. More than a few private aerospace companies hope to cash in on the (really) high speed jet travel market. And NASA’s in on the game, too.

There’s no great secret to supersonic flight: It’s about adding power until the aircraft can break the sound barrier. That power has always come from conventional fuel, and lots of it. With the clock ticking on fossil fuels, future aircraft will need to use less fuel or rely on renewable energy sources.