How soon will supersonic jets return to our skies?

A new era of supersonic flight might be just around the corner, but there are three challenges to overcome when it comes to flying faster than the speed of sound. Those are the three Es of aviation: engineering, environment and economics. Concorde, the aeronautical marvel that made its last flight 16 years ago this week, only conquered the first of those three travel challenges. The world's slinkiest airliner could transport passengers across the Atlantic in less than half the time taken by other commercial aircraft, but it still had ecological shortcomings and high operating costs. Now at a time when carbon emissions and our planet's well-being are in the spotlight, can a return to commercial supersonic flight really be sustainable, profitable for airlines and manufacturers, and affordable for passengers? There are two US companies that certainly think so, and they're going full throttle with plans to bring supersonic airplanes to market by the mid-2020s. The journey times suggested are as short as New York to London in three hours, 15 minutes. One is targeting airlines, the other the executive jet market, and they've both got different solutions to one of the major environmental sticking points of supersonic flight: how to manage the sonic boom. Story has more details.<br/>