IN what may become the face of modern aviation, Nasa has unveiled three concept designs for quiet, energy efficient aircraft which it says could be ready for flight as soon as 2025. Lockheed Martin, Northrop Grumman and Boeing came up with the designs and all the three companies won a contract from the US space agency to research, develop and test their concepts in 2011, the 'Daily Mail reported. The designs came about after Nasa revealed it was aiming to develop a line of super planes that are faster, larger, quieter - and burn fuel more efficiently and cleanly than their present counterparts. Criteria set by Nasa meant that each design had to fly up to 85 per cent of the speed of sound, cover a range of about 7,000 miles and carry between 50,000 and 100,000 of payload; either cargo or passengers. Now, each of the three companies will spend the rest of this year exploring, testing and simulating their designs in the hope that NASA will choose it for development. TOI