Perhaps the most fascinating aircraft ever built and flown was the Lockheed Martin SR-71 Blackbird. Alas, it was taken out of service in the late 90's and there's been nothing quite like it since.
Now, much to the delight of aviation enthusiasts, Lockheed has announced the Blackbird's successor; the SR-72.
Looking more like a high-tech shark than a bird, the SR-72's predecessor could cruise at Mach 3.2 (2,436 mph) with an 85,000 foot ceiling and a rate of climb just over 2.2 miles per minute!
The Lockheed Martin SR-71 Blackbird
Developed by Lockheed's legendary Skunkworks division, the SR-71's first flight was in 1964 and after 32 were built and flown in 3,551 mission sorties the program was finally retired in 1998.
The SR-71's list of records (such as "Speed Over a Recognized Course" record for flying from New York to London, a distance of 3,508 miles at an average of 1,435.587 mph in 1 hour 54 minutes and 56.4 seconds) is astounding but it's the technical details of how the aircraft operated that are a true geek-out: For example, because of the heat generated by traveling at such high speed, the skin of the aircraft was made of a corrugated titanium alloy so that it could expand without buckling and prior to flight, when the airframe was cold, the gaps in fuel system were large enough that jet fuel leaked out on to the runway!
(Check out Flying the SR-71 Blackbird for a great account of actually piloting a Blackbird and out-running rocket-powered missiles).
Artist's rendering of the Lockheed Martin SR-72
Combining an "off-the-shelf turbine with a scramjet to power the aircraft from standstill to Mach 6 plus" the "outline plan for the operational vehicle, the SR-72, is a twin-engine unmanned aircraft over 100 ft. long ... about the size of the SR-71 and have the same range, but have twice the speed ... and could be in service by 2030."
The SR-71 cost $43 million each back when it was accepted by the US Air Force in 1968. There's no estimate on what the SR-72 will cost but if you're an aviation enthusiast it'll be worth whatever it costs.