The fastest air-breathing machine to ever be built.

The Lockheed Martin SR-71 "Blackbird" reigned supreme for over three decades as America's premier spy plane. Capable of reaching speeds over three times the speed of sound, the SR-71 still holds the record for the fastest air-breathing manned aircraft ever created.

Although retired in 1999, the Blackbird's creators, Lockheed Martin, recently announced they planned on building the SR-72, an unmanned hypersonic successor to the SR-71. The construction of this aviation marvel is headed by Lockheed Martin's advanced development program known as Skunk Works.

The crew at Skunk Works are equipping the SR-72 with two hybrid jet/rocket engines with the potential to reach speeds in excess of Mach 6 (7350.26 kph), with Lockheed hoping the jet will be able to reach any destination on earth within an hour. It's also believed the aircraft will be fitted with high-tech weaponry, meaning along with being sent out on recon missions, the SR-72 could also be used to strike specific targets. 

SR-72 3

“Hypersonic aircraft, coupled with hypersonic missiles, could penetrate denied airspace and strike at nearly any location across a continent in less than an hour,” said Brad Leland, Lockheed Martin program manager. “Speed is the next aviation advancement to counter emerging threats in the next several decades. The technology would be a game-changer in theatre, similar to how stealth is changing the battlespace today.”

Lockheed Martin has confirmed ground tests have been conducted on the powerful engine and they're planning on beginning aerial testing in the early 2020s, with an actual finished model of the SR-72 hopefully in the air during the early 2030s.

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