1- Wikipedia: Definition; Precursors; Orbital space tourism: list of flown space tourists, Dates, Prices; Suborbital flights; Space tourism groups.
2- Hobbyspace: Development of space tourism since 2001.
3- Virgin Galactic: Leader in the field of space tourism.
4- BBC: Risks; Clients (wealthy and wanting to experience something different).
5- Images (don't forget to mention the source of the images used).
