Space has been an interest for philosophers and scientists for much of human history, and hence it is difficult to provide an uncontroversial and clear definition outside of specific defined contexts. Disagreement exists on whether space itself can be measured or is part of the measuring system. (See Space in philosophy.) The term is also used somewhat differently in different fields of study. Many fields use an operational definition in which the units of measurement are defined.
In mathematics, a space is a set, with some particular properties and usually some additional structure. It is not a formally defined concept as such, but a generic name for a number of similar concepts, most of which generalize some abstract properties of the physical concept of space.
More on [ Space ]
Adventure and Sports :: Specialty Travel
Space :: Technology
X prize :: Launch Vehicles

Virgin Galactic - Airline offering suborbital spaceflights with a new version of SpaceShipOne. Provides description of flights, the vehicle and offers bookings starting 2005.
Meta Description: [ Virgin Galactic has licensed the technology required to send paying passengers for space rides in the next 2-3 years. We are therefore, the world's first 'spaceline'. ]
Alltra - Space Transportation - Offers information on projects, designs and overview of this association of German specialists promoting space transportation and tourism.
Meta Description: [ Aerospace, ALLTRA, Space Transportation ]
FAR - Overview, news, projects and membership info of a German association promoting low cost space flight and space tourism.
Meta Description: [ Forschungsgruppe Alternative Raumflugkonzepte ]
Reason Interview: Burt Rutan - Space entrepreneur Burt Rutan talks about how private space flight policy should emphasize innovation, safety, �and having a good time.
Meta Description: [ Space entrepreneur Burt Rutan on how private space flight policy should emphasize innovation, safetyand having a helluva good time. ]
Space Future - Features news and an e-zine dedicated to space tourism, habitats and vehicles by a pro-space group. Frequently updated.
Meta Description: [ Space Future is for everyone who'd like to visit space. Features include the archive of space tourism work, information on vehicles, tourism and power plus mailing lists and the Space Future Journal. ]
Space Island Group Project - Features a project descriptions for building a space station devoted to tourism and 0-G experiments, based on the tanks of the space shuttle. Regularly updated.
Spacetopia - Provides membership forum and documents of Japanese organization, and of a club dedicated to space tourism.
500
Spacetourist - Features a various sources of information on spacetourism opportunities.
Meta Description: [ SPACETOURIST space tourism rocket rocketplane astro extreme action tourist adventurer news site personal space vehicles beamships space elevators RLV X vehicles X-15 X-33 X-24 X-1 space congress links mp3 star vacation space sweepstakes ticket to ride the real right stuff space sports space trai... ]
Zero-G - Features information on parabolic flights (Zero-G) available to the public for experiencing weightless conditions.
| Reports about space travels, exploration of the cosmos & latest discoveries, produced in cooperation with ESA. | |
| Next Video | |