The SR-72 Will Be the Fastest Aircraft in the World:Although the original Blackbird was an unarmed reconnaissance aircraft, the SR-72 will reportedly support Lockheed Martin’s new High-Speed Strike Weapon (HSSW). And while the world was watching closely when the Chinese tested their hypersonic missiles, the Son of Blackbird will reportedly fly at a blistering Mach 6 or 4603 mph or twice the speed of the original SR-71.