In aviation, being bigger isn’t always better. Despite being the undisputed giants of the modern age, neither Boeing’s 787 Dreamliner nor the massive Airbus A380 are particularly inspiring; don’t we all yearn for a return of the supersonic age?
Those who pine for the turbojet-powered Concorde, which retired 10 years ago after taking more than 2.5 million passengers on regular 3½ hour crossings from New York to London, can now look forward to an age not of supersonic, but hypersonic aircraft. It looks set to make Concorde look like the 1960s technology it was.
Lockheed Martin’s new prototype SR-72 jet – though just a two-seater for now – can theoretically travel from New York to London in under an hour, reaching speeds of up to Mach 6 – about 7,350km/h, or roughly six times the speed of sound. Concorde travelled at a top speed of 2,173km/h, just under Mach 2.
Despite the popular lament at Concorde’s premature demise, it’s not that trailblazer that the SR-72 has to live up to. The SR-72 comes from the same legendary Skunk Works division of Lockheed Martin that in 1964 developed the SR-71 Blackbird, a two-seater that remains one of the fastest aircraft built to date. Capable of Mach 3, the SR-71 – which was used for spying until 1990 – flew from New York to London in less than two hours % in 1976.
It also holds the record for travelling between Los Angeles and Washington DC in just over an hour.
Seven years in development so far, the similarly two-seater, twin-engine SR-72 can maintain such incredible hypersonic speeds because of its use of a scramjet supersonic combustion engine, which “breathes” compressed air, though to get to the very high speeds requires a regular turbine engine.
Joining the two separate systems together – the “combined cycle propulsion” concept – is the neat trick inside the SR-72.
Not surprisingly, the SR-72 has been earmarked for use by the US Air Force for intelligence, surveillance, reconnaissance and devastatingly rapid strike missions. At Mach 6 speeds, the SR-72 could transform aerial combat, moving from one side of a continent to another in a matter of minutes.
“Hypersonic aircraft, coupled with hypersonic missiles, could penetrate denied airspace and strike at nearly any location across a continent in less than an hour,” says Brad Leland, Lockheed Martin programme manager of hypersonics. %
“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 battle-space today,” Leland says.
The SR-72 – being constructed by rocket-makers Aerojet Rocketdyne and the US Air Force – isn’t quite ready for take-off, but is expected to be whizzing through the upper atmosphere on test missions within a decade. It likely won’t be fully operational until 2030.
But such is the safety-first nature of the aviation industry that the SR-72 would need to go through another 15 years or so of rigorous testing before it could develop into the world’s fastest private jet plane.
The small size of the cockpit makes sure of that, although %the technology behind it could %seep out into some future commercial airliners.
We might not be flying at hypersonic speeds any time soon, but it’s good to know that cold war-era achievements are at last being surpassed.