David Cullen

Humans have a knack for sharing intimate moments in unlikely places, as membership of the mile-high club demonstrates. So there is a significant chance that the launch of the space tourism sector may be swiftly followed by the first sex in space.

But having researched the issue, my colleagues and I believe that space tourism companies haven’t adequately prepared for the consequences of people joining what we could call the “Kármán line club” (referencing the 100km-high boundary between Earth and the rest of the cosmos).

Talk of space tourism has always been in terms of the distant future. But sub-orbital space tourism – short flights with only a few minutes of spaceflight and weightlessness – already exists. Tickets range from freebies, to costing millions of dollars.

Much longer flights are just around the corner. Companies such as Elon Musk’s SpaceX have well-established track records of developing spacecraft faster