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�鶹��ý has been in print since 1956, around the time ideas for Concorde, the supersonic Anglo-French airliner, were starting to germinate. It was an exciting period for technology. The first Sputnik satellite was launched the following year and the idea of flying faster than the speed of sound grew out of that space age optimism. Yet by 1986, Concorde’s problems were appearing. “It was a triumph for technology in design, materials and engines – but a commercial disaster,” in our 30th anniversary issue.

Our coverage didn’t stop there, however. As well as reporting on Concorde’s fall from grace, we’ve written about the ideas that might finally make supersonic flight a realistic mass transport option – a future that now seems nearer than ever.

1971

“The best thing that any business man can do with his few hours saved by flying supersonically is to have a few more Martinis”

Concorde’s first commercial flight wasn’t until 1976. But five years earlier – and just two years after the prototype first flew – �鶹��ý was wondering . Leaving aside the prestige of making Concorde work, was there actually a market for the idea if it only saved a few wealthy people a little time?

1988

“Flying supersonically needs a pure jet but you don’t want that on the ground”

Most jet airliners have “turbofan” engines that suck in a lot of air but accelerate it relatively slowly. That makes them much quieter than Concorde’s “direct jet” engines. These pumped air through them as quickly as possible to achieve faster speeds. By the late 1980s, Rolls-Royce wanted to so they could switch between the two systems, with the quieter one working during take-off to avoid making the racket Concorde did.

1994

“A fleet of ‘daughters of Concorde’ could trigger greater destruction of ozone”

Concorde could fly at about 60,000 feet, way above the typical 35,000 feet at which passenger jets cruise. This took it well into the stratosphere, where tiny droplets of unburned fuel in its exhaust might help destroy ozone. In the 1990s, when plans for Concorde’s successors were being proposed, atmospheric chemists banded together to .

2000

“A tyre burst alone should never cause the loss of a public transport aircraft”

On 25 July 2000, a Concorde took off from Charles de Gaulle airport in Paris and minutes later crashed into a hotel on the outskirts of the city, killing all 109 people on board and four people on the ground. It was the only accident in Concorde’s 27-year operating history, but it tarnished the plane’s reputation. Investigators later found that the plane had , which fired a piece of tyre into the wing fuel tank, causing a fire.

2002

“This aircraft was chosen because its wings are more flexible than those of most others”

Concorde did not retire from service until 2003, but long before that engineers were dreaming of the next generation of supersonic aircraft. In 2002, the US air force rather than using flaps as conventional planes do. The hope was that this strategy would lead to a next generation of lighter – and so faster – supersonic jets.

2004

“Its radical, air-breathing engine can function at speeds of nearly 12,000 kilometres per hour”

Things accelerated quickly after the flexible winged F-18 project. A few years later, NASA’s prototype X-43A scramjet flew for 10 seconds at . The plane didn’t have to resort to using rockets, which carry fuel and oxygen, to reach that speed. Instead, it managed to suck in oxygen from the air quickly enough to burn fuel at a fast-enough rate.

2005

“The launch ended in disaster when the aeroplane separated from the rocket and fell onto the launch pad”

The Japanese had been interested in developing rival supersonic aircraft for decades. The focus was on producing an aircraft that was both quieter than Concorde and had a greater range – so it could make trans-Pacific flights. By the mid-2000s, the Japan Aerospace Exploration Agency had begun testing its designs, but .

2006

“Even if the airplane works as hoped, there is no guarantee that aviation authorities will let it fly”

It wasn’t just government agencies that cared about supersonic flight. Private firms also thought there might still be a market despite Concorde’s retirement. In 2006, a consortium called Supersonic Aerospace International commissioned Lockheed Martin to design a private jet that could travel at Mach 1.6. But as �鶹��ý reported, there was never any guarantee it would be allowed to fly in US airspace, due to the ban on supersonic flight over land.

2009

“We’re pretty close to being able to control sonic booms”

More recently, it has looked more and more feasible that sonic booms can be softened. Eight years ago, NASA . The idea was that if the shock waves produced by the front and rear of a plane could be spread out, the resulting boom would be muffled. The agency’s latest research suggests that this sort of technique could change the boom from sounding like two sharp rifle shots to something more like a low, thunderous rumble. The dream of supersonic flight, it seems, is still alive.