Aircraft enthusiasts are waiting with growing anticipation for the unveiling plans for a supersonic jet that may be able to fly London to Sydney in just four hours. The race to build a successor to Concorde: Boeing, gulfstream and NASA join forces to create a supersonic jet capable of flying from London to Sydney in four hours. U.S. builders helped by the NASA Space Agency - will reveal the prototype successors to Concorde at the Farnborough air show that is meant to take place before the year runs out. Boeing, Lockheed Martin and Gulfstream are leading the way to build the new supersonic passenger plane which will be targeted at first at the business jet market. Artist's impression of the new supersonic commercial passenger aircraft which will fly at speeds of 2,500 mph All three companies believe they are close to reduce the sonic boom to a sound described by a Gulfstream engineer as 'closer to a puff or plop'. Unlike Concorde's loud boom which forces it to routes away from land and damaged its commercial chances, this supersonic jet would be as quiet as possible. Concorde flew for the last time in November 2003. He said: 'The fact that the big boys are all close confirms industry rumours that a new generation of supersonic planes is now, finally, within reach. Lighter composite materials, more advanced engines and smaller fuselages could enable new jets to travel about twice as fast as Concorde, which flew at up to 1358mph, according to the Sunday Times. Passengers will travel at speeds of more than 2,485mph, allowing them to cruise in luxury from London to Sydney, just over 12,000 miles away. Currently, the fastest subsonic executive jet, Gulfstream's new G650, can fly 7,000 miles at a 646mph and has a top speed of just 704mph. Last January, NASA released images of a test plane in a wind tunnel which suggested the sonic boom could be virtually silenced using Super-thin wings and hidden engines. The Challenge is not just technical: builders have to prove politically that it is acceptable to the public.