The Defense Advanced Research Projects Agency (DARPA), charged with the development of new military technology, recently announced the construction by 2016 of an extreme hypersonic plane, capable of reaching speeds of up to Mach 20 (20 times the speed of sound, or 21,000 km/h). That speed would be sufficient to travel anywhere on the planet in slightly less than an hour.
Hypersonic Technology Will Reach Anywhere on the Planet in an Hour

August 07, 2012