Richard Branson's spaceflight company, Virgin Galactic, has said that it hopes to one day be able to offer super-fast passenger jet services which could cut the time of a London to Sydney journey to as little as two and a half hours.
Speaking at the Wired 2013 event in London yesterday, Virgin Galactic commercial director Stephen Attenborough announced that the company was looking at the idea of using its SpaceShip 2 private spacecraft for long-haul flights.
The idea would be possible by using the Virgin craft's ability to fly at the very edge of space to cover huge distances in a short space of time, re-entering the Earth's atmosphere for landing. Virgin would need to wait until it has successfully operated its pioneering space tourism programme first, however.
"If we can get this first step right, take people into space and keep them safe in commercially viable aircraft, the aim to try and push long haul aviation above the fragile atmosphere into space," said Attenborough.
The possibility of commercial spaceflight replacing traditional aviation has perceived environmental benefits as well, with Attenborough explaining that this should be 'environmentally a lot better' as some harmful emissions would be released outside of the Earth's atmosphere. Virgin's SpaceShip 2 is expected to begin taking passengers to the edge of space next year. More than 580 people have signed up for a ticket so far, at a cost of at least $200,000 each. The craft, which can hold six passengers, is carried to an altitude of 46,000ft by a larger aircraft, White Knight 2. It then uses a rocket booster to reach a height of 68 miles above the ground, where passengers will experience zero-gravity.
Attenborough described what a trip would feel like, following the release of SpaceShip 2 by its carrier. Following a countdown, 'everything in the cabin changes dramatically'. The spacecraft travels at 170 knots in gliding mode, but with the activation of the rocket, it reaches the speed of sound within six seconds, experiencing 3.5G acceleration going upwards, accelerating to four times the speed of sound.
'Just when you are getting used to the noise, vibration, g-forces, the sheer -- I was going to say terror -- the sheer thrill of it all, then they cut the rocket motors out,' said Attenborough. 'So you suddenly weigh nothing at all. There's no point being in zero gravity if you are just going to be strapped to a chair.' The cabin has been designed to allow passengers to float around, unconstrained, for the few minutes that they will experience weightlessness.
The craft is capable of re-entering the atmosphere at any angle without the kind of heat shields required on a space shuttle - partly due to its lower speed, and partly to the ability to "feather" its wings: the aerofoils on SpaceShip 2 rotate to create an aerodynamic effect similar to that of a shuttlecock, slowing the ship down without heating it up.
This is crucial to any long-distance commercial flights, as the ability to cross the globe in a matter of hours would depend on flying in the vacuum of near-space, using gravity to "glide" around the world before re-entry.
A test flight in September successfully demonstrated the "feathering" process - the first time that it had been integrated into a test flight with every other aspect of the journey.