Commercial space flights gearing-up for lift-off

Most of us have read "1,001 places to visit before you die" and other such morbidly titled lists. But none of these yet include a trip to suborbital space. Yet space is the travel industry's next big destination - and those suborbital holidays may be starting sooner than you think.

So far Virgin Galactic, part owned by British industrialist Richard Branson, has gathered more than HK$500 million in deposits from 600 people intent on a ride on its SpaceShipTwo. It will carry six passengers at a time on an "out-of-the-seat" zero-gravity experience into the black of space at a cost of HK$1.9 million for a two-hour trip.

That price includes training at a centrifuge facility and zero-gravity parabolic flights. It might sound outrageously expensive, but fewer than 600 people have ever visited space. So doubling that figure, however long it takes, will represent a giant leap for mankind.

Virgin Galactic will become the world's first commercial "spaceline" when its first passenger flight takes off. That may happen later this year. But although it's tempting to do so, don't confuse space flight with a ride in a very high aircraft.

The figures underline the difference; while a commercial airline cruises at 11 kilometres, SpaceShipTwo will breach the 100 kilometre Kármán line - the division between the earth's atmosphere and space - to reach an altitude of 110 kilometres.

It's an expensive place to visit, largely because you have to be travelling at 16,000 km/h to reach it. Testing is still in progress, but in April, Virgin Galactic completed its first rocket-powered flight - which including supersonic Mach 1.2 speeds - from its base at Spaceport America in Mojave, New Mexico.