>It doesn't have to be profitable, that's just unavoidable. The opening statement suggests it's indeed the case, And not just for sale to earth, the amount of space available combined with the fact we already know it's possible suggests it's assuredly giving returns. For the sale to Earth, by 2050, definitely. And not just novelty. Food will be a valuable comodity. Arable farming space is already at a premium, and population growth will make that problematic. Look into it. Microgravity isn't good for long term exposure for people - sure, there might be farming potential, but long term habitation is a problem. A whole list of problems. As to "wasting gravity" - providing axial rotation to an entire vessel, or even a small part therof - isn't overly difficult to achieve. It doesn't cost money as much as it costs energy - and with establishing energy farms as well as traditional, this can be rendered "costless". Besides, to get to realistically consider such endeavours such concepts will of been rendered moot, and even something primitive like solar panels can provide enough to get it spinning "costless", either as a total mass or just a toroid section connected to a static spire buffered with fluid bearings.

Scrabs, I think what Adolru means by 'wasting gravity' is that 'making' artificial gravity costs extra money. Therefore it is best that everything that can be done in microgravity, should be done in microgravity, so that we don't 'waste' precious gravity. Greeting Jens

How do you "waste" gravity? Even if it is simulated by axial rotation, it's either there or not. Fish and plants would be like humans - they would behave in a predictable manner when subject to "normal" gravity. Putting zero / microgravity into the equation created unnessary issues and unpredictability.