In late September, a secretive experimental vehicle roared into the clear blue skies above a military base deep within the Arctic Circle in Norway. As the sleek, rocket approached its target altitude of 350km (218 miles), it began to arc back to earth, gradually accelerating to so-called hypersonic speeds of up to Mach 8 – about 9,800km/h (6,100 mph).
The test was the fifth of nine planned launches for the Hifire vehicle, which its backers claim “could be a major step forward in the quest for hypersonic flight”, generally regarded as Mach 5 and above. At these speeds, headline writers like to say, we could soon be zipping from London to New York in just one hour.
It is a promise that is often repeated about Hifire and other vehicles, such as the experimental US Air Force X-51A WaveRider, that had its latest (unsuccessful) test in August. Yet, delve back in history, you find similar promises.
In the pages of popular books, magazines and newspaper comics, the hyperfast world of airline travel was predicted to be just over the horizon. There was seemingly no limit to humanity’s capability to zip about the globe with increasing speed. In his 1965 book Supersonic Transport, Irwin Stambler charts the progression of time it took to cross the Atlantic in history: from 350 hours on wooden ships to 120 hours on steam ships to 60 hours in dirigibles to 12 hours prop planes to 6 hours in planes of the very near future. The graph continues and projects forward to when the one hour barrier would be passed.
It was written at a time when air travel was emerging as a reasonably affordable option for many middle class people and there was reason to be optimistic that not only would prices continue to fall, but jets would continue to get faster.
Needle point nose
This period of optimism started on 14 October 1947, when Air Force pilot Charles “Chuck” Yeager dropped from the bomb bay of a B-29 bomber in the experimental X-1, a rocket-powered airplane that was the first to break the sound barrier.
In the following years, the prospect of supersonic – and faster - air travel was always just around the corner. On 22 January 1953, for example, the Gleaner, a paper based in Kingston, Jamaica, carried a story from the Associated Press with the headline “London to N.Y in one hour seen”. The story quoted a talk given by the then chief executive of British Overseas Airways to the Aircraft Recognition Society. "In the next 50 years our grandchildren will probably be looking at supersonic commercial aircraft carrying up to 500 passengers at fares cheaper than third class travel today,” he was quoted as saying.
The first vehicles to begin to test these claims – as with today’s hypersonic craft – were built and operated by the military. This was in part out of necessity and precedent. But, as Stambler notes in his book, building a military plane and a commercial “supersonic transport” for passengers are two completely different challenges. Providing an acceptable experience for paying customers (taking into account high temperatures, appropriate cabin pressurization, and so on) is one of the obvious and yet daunting challenges of non-military high-speed aircraft.
But that didn’t stop people trying. In Europe, the UK and French governments subsidised designs that would eventually become Concorde, while in Russia, plans were revealed form the Tupolev Tu-144, nicknamed Concordski for its similarity to the European craft. In the US, various firms hawked competing designs. In a 1960’s Popular Mechanics article titled “Here’s a peek at tomorrow’s huge planes”, the writer describes two different designs from North American Aviation and Lockheed. The North American Aviation was designed primarily for military use, but Lockheed focused on the mass market.