The secret to two-hour flights to London
Travelling faster than the speed of sound has its advantages. Being in London by lunchtime is one. But before the travel time between Tullamarine in Melbourne and Heathrow in London is cut to as little as two hours, there are certain technical hurdles that must be overcome.
One of the barriers is creating aircraft materials that won't melt or malfunction under extreme temperatures reached during hypersonic flight.
Melbourne researchers have come up with an alternative technique of making the ceramic parts needed to withstand temperatures in excess of 3000 degrees, bringing the prospect of travelling to Europe in a few hours closer to reality.
The solution involves ceramics and some clever chemistry.
''If you want to make a sand castle at the beach and you use dry sand, you have to apply lots of pressure to get it to stand,'' said material scientist Carolina Tallon from Melbourne University. ''But if you add a little bit of water to the sand, it will hold the shape of the bucket much better. And this is what we are doing.''
Working with a team of researchers from the Defence Materials Technology Centre, the University of Queensland, Swinburne University, the Australian Nuclear Science and Technology Organisation and BAE Systems, Dr Tallon said adding liquid and chemicals to the ceramic mix had produced a material which was able to survive temperatures above 3400 degrees. ''It's like making a cake. You put the mixture in a mould and then take it out and put it in a furnace to cook,'' she said.
''The ceramic pieces we have made are stronger and will survive to higher temperatures than those used on the space shuttle.''
In preliminary testing, the ceramic material survived 3400 degrees for three minutes without any damage to its shape or material integrity.
The technique has other advantages, including that the ceramic components can be made at lower temperatures and pressures. This saves time, money and energy.
Jets that travel up to five times faster than the speed of sound already exist - but they can only achieve these speeds for a few seconds, as the extreme heat generated on areas of the wing and nose can melt or damage the aircraft.
The ceramic material developed in Australia by Dr Tallon and her colleagues would be placed around the nose and wings of an aircraft, as these areas - known as the ''leading edges'' - get the hottest.