SR-71 Blackbird successor will do 4500mph

It's not strictly car news, but if you like fast things and stunning feats of engineering, you need to know this: Lockheed Martin is developing a successor to the SR-71 Blackbird, the fastest aircraft in history.

If you're not now jumping up and down and screaming with excitement, you must read James May's guide to the SR-71 to understand just what a high watermark of humanity it really was.

READ JAMES MAY'S GUIDE TO THE LOCKHEED MARTIN SR-71 BLACKBIRD

Here's the York notes version. Devised in America in the depths of the Cold War to outrun Soviet surface-to-air-missiles, the titanium SR-71 was the most advanced aircraft of its day, and remains the fastest plane in history.

In 1976, the reconnaissance craft flew from New York to London in - wait for it - 1hour 54 minutes 56.4 secs, at a peak velocity around Mach 3.2 (2436mph), which remains a record for an air-breathing aircraft. It also, at 85,131ft, flew higher than any aeroplane before or since.

So how do you follow an act like the SR-71? Perhaps unsurprisingly, with the SR-72. Unlike the original Blackbird, this craft will be unmanned, but should be twice as fast, with a cruising speed around Mach 6. Which is 4500mph.

Such pace doesn't require vapourware, but rather technology Lockheed Martin has already developed. Specifically it'll use LM's ‘combined cycle propulsion', which essentially joins a turbine and ramjet in a single engine, the former powering the SR-72 from take-off to Mach 3, the ramjet taking over to shove it to Mach 6. That's the sort of hypersonic speed that could revolutionise aerial combat as we know it.

"Hypersonic aircraft could penetrate denied airspace and strike at nearly any location across a continent in less than an hour," Lockheed Martin's Brad Leland told Aviation Week. "The technology would be a game-changer in theatre."

Lockheed says a demonstration aircraft could fly by 2018, with the SR-72 operational by 2030. Will this be the aviation world's next ‘Veyron moment'? And anyone else trying to figure out whether it'd be possible to fit a turbine-ramjet in the engine bay of a Lotus Exige?