It is that massive jump that is the biggest issue. Do we, as travellers, really want to be stuck inside a metal (sorry, composite material!) tube for 19 hours? The Blue Swan Daily as already highlighted that ultra-long-haul is already here today, but the debate remains on the 'nonstop versus transit?' question, one that has not yet been fully answered.
Project Sunrise could push aviation boundaries in the early 2020s, but could ultimately just be a short-term milestone that advances in technology that have conceived this opportunity could go on to confine it to the history books just a decade later.
With duration the biggest question mark over these flights the idea that travellers could fly between Britain to Australia in just four hours by the 2030s using a new hypersonic engine being developed by UK scientists, could take long-haul connectivity to a whole new level.
Reaction Engines, based in Oxfordshire, are in the process of building a hybrid hydrogen air-breathing rocket that will allow a plane to fly at Mach 5.4 - more than twice the speed of Concorde - then speed up to an unbelievable Mach 25 in space! What's more the hydrogen/oxygen 'Sabre' engine is claimed to be far greener and cheaper than current powerplants.
It all seems like something from a chapter of an academic science journal highlighting the future potential for travel. But, even a generation ago the thought of travelling non-stop from Europe to Australia was not seen likely. Away from the UK - Australia focus, the value of this hypersonic invention would be massive for the business travel world. A flight from London to New York would be slashed to just over an hour.
The UK government may not have been willing to invest in providing a lifeline to Thomas Cook last week, but it has already invested GBP60 million in the development of this engine, a sum that has been reportedly matched by Rolls Royce, BAE Systems, and Boeing. It has also committed to work more closely with Australia in a 'space bridge' partnership.
Sabre is an acronym for Synergetic Air Breathing Rocket Engine which will deliver the five times the speed of sound performance required for hypersonic travel. It has been described as "a hybrid of a rocket engine and an aero engine".
It works by chilling the incoming air from 1800F (1000C) to zero using tiny tubes of super-cooled helium. The captured heat is also used to power the engine. This allows the spaceplane to take off horizontally and reach speeds of 4,000 mph for fast commercial travel, and ultimately reach speeds of 19,000mph in space.
It may still sound a little science fiction for many. After all, delivering a sustainable hypersonic solution is difficult to achieve without overheating the engine. But, the CEO of UK Space Agency, Graham Turnock firmly believes scientists and engineers are developing something viable. "When we have brought the Sabre rocket engine to fruition, that may enable us to get to Australia in perhaps as little as four hours," he confirmed at a conference last week.
And it is the hybrid of rocket and aero engine that could make it all possible and allows the rocket to breathe air," according to Reaction Engines' Shaun Driscoll. "Rockets really haven't progressed in 70 years, whereas aero engines have become very efficient. So, if you can combine an aero engine and a rocket you can have a very lightweight efficient propulsion system and basically create a space plane. The physics checks out but the challenge is building a test regime," he explains.
The Reaction Engines team and its partners are currently trialling parts of the engine in Denver, Colorado, and are hopeful to begin test flights in the mid 2020s, before commercial flights in the 2030s. That's not really that far away!