There are numerous questions surrounding this nascent form of tourism. Many focus on the technology in place to deliver it, the legislation that is necessary to safeguard it and, most recently, the pragmatic questions of where spaceports should be placed. But, often overlooked is the issue of exactly what the industry will look like and who it will target, which isn't as clear cut as you might assume. The plan is to start space-plane operations by 2018, so who can we expect to be taking part in this new frontier of the travel industry?

Space tourism" is a catch-all term that encompasses three different ideas of what the industry could look like. These are: "space tourism", "personal space flight" and "citizen space exploration".

As well as being used to encompass all three strands, "space tourism" can also be used in a more specific sense. In its purest form, it puts forward a mass-market future that emphasises the sight-seeing potential of trips into space. Although Virgin Galactic may aspire to this goal, they have for now focused on trips for the very wealthy, not the expansion of the market.