'SPACE: THE final frontier,' the iconic opening words to the 1960s television series Star Trek, were uttered at a time when space travel was confined to the realms of science fiction - and a few professional astronauts. The show, featuring characters with pointy ears in bright tight suits making hand gestures, is one of many cult hits that has fed a curiosity for space exploration. Others such as 2001: A Space Odyssey, Star Wars and even The Jetsons, and historic milestones such as Soviet cosmonaut Yuri Gagarin's space walk and Neil Armstrong's 1969 moon landing have also captured the public's imagination. Fast-forward 50 years and space travel is now accessible to mere citizens - provided, of course, they fork out some serious cash. Since 2001, seven tourists have had out-of-this-world experiences thanks to US company, Space Adventures, which sends clients to the International Space Station, the largest artificial satellite to orbit Earth. 'Since the dawn of manned spaceflight, just over 500 people have travelled to space - now you could be one of them,' says its website. Once travellers reach the Earth's orbit, they hit speeds of more than 27,500 km/h, are more than 322 kilometres above the Earth's surface, and get to experience a weightless environment. American engineer Dennis Tito, who spent eight days in space in 2001, holds the honour of being the world's first private space explorer (he reportedly paid a cool US$20 million for the privilege). About a year later, South African technology entrepreneur Mark Shuttleworth made the trip, followed by American entrepreneur and scientist Gregory Olsen in 2005. The fourth private space explorer, Anousheh Ansari, followed in their galactic footsteps in 2006. Like her predecessors, Ansari had a scientific and entrepreneurial background, but she was the first self-funded woman to make the trip. Her biography, My Dream of Stars: From Daughter of Iran to Space Pioneer, chronicles her journey. Next up was entrepreneur Charles Simonyi and game developer, Richard Garriott. The American duo shared details of their missions online at www.charlesinspace.com and www.richardinspace.com respectively. Simonyi, former head of Microsoft's application software group, is to date the only repeat traveller, having flown in 2007 and 2009. Garriott made the trip in 2008. As expected, the elite group of travellers have relayed stellar reports of their trips. 'I have a new-found sense of wonder seeing the Earth and stars from such an incredible perspective,' said Olsen upon his return. But orbital space travel does not involve a ready-packaged leisurely visit. Ansari says she trained for six months in Russia in preparation for her trip, and Shuttleworth, a year. For this reason, Ansari objects to being called a 'tourist'. Canadian entertainment tycoon and philanthropist Guy Laliberte, the most recent citizen to be launched into space, broke the mould by sending a green message in 2009. The founder of Cirque de Soleil and, more recently, a charity which aims to provide safe water to the poor, Laliberte's trip reportedly cost almost US$40 million and was billed as the 'first social artistic mission in space'. Laliberte hosted a show from space that was broadcast on television and online and featured performances by celebrities including Bono and Salma Hayek. Space hotels have also jumped on the space-tourism bandwagon, including the Galactic Suite Space Resort. Based in Barcelona, the company hopes to have its first orbital resort by 2012. With rooms boasting moon and Earth views, a three-night stay which involves an eight-week training stint on a tropical island, costs Euro3 million (HK$30.83 million). Space Islands, on the other hand, is a commercial space station project run by Hilton International and, when completed, will be called the Hilton Orbital Hotel constructed from used space shuttle fuel tanks. Meanwhile, the Bigelow Sundancer space hotel aims to launch in 2014. The brainchild of billionaire Robert Bigelow, founder of the Budget Suites hotel chain, the Sundancer is a breakthrough in the private space tourism with a stay in the hotel - which revolves around the Earth - to cost about US$8 million a week per person. The latest corporate player in the space tourism market is Boeing, with the aviation giant aiming to start flights in 2015. Tickets are to be marketed by Space Adventures and prices have not yet been set. A more affordable option than orbital travel, suborbital travel - which involves reaching space, but without orbital revolutions - has been developed in recent years. Since 2005, the most high-profile of them, Virgin Galactic, has offered passengers the chance to reserve a spot on SpaceShipTwo, billed as 'the world's first commercial spaceline', for a starting price of US$200,000. SpaceShipTwo is to commence flights after testing programmes and licensing procedures are completed. The company has not set a date for commercial space flights, but says that passenger flights would not happen before 2011. Singer Katy Perry splashed out on a ticket earlier this year, as a birthday present for fianc? Russell Brand. According to Virgin Galactic, travellers will reach speeds of more than three times the speed of sound, view the Earth and experience near-zero gravity. And the best part is, flights only require three days preparation. Ambitiously, the company says it plans calling for 50,000 'ordinary people' to travel into space in the first 10 years of operation, and that about 340 people have already reserved spots. Interested parties with the passion, cash and courage to join their ranks can make a direct booking on its website - or, of course, with any of their 'accredited space agents'.