I am sitting on a sofa, floating through the void. Above me, a massive silver sheet billows in a gentle breeze. The chair drifts on through the blackness, with nothing to stop it carrying on forever.

The peculiar sensation of flying through space on a cushioned bench is extremely relaxing – disorientating but not dizzying. The smoothness of travel means that my companion on the sofa – a Nasa spacecraft engineer – is sitting with her legs crossed and eyes shut in an apparent zen-like trance as we spin gently through the dark.

Sadly, all too soon our space sofa bumps up against the boarding platform and we step back onto the solid ground of Nasa’s – literally named – Flat Floor Facility at the Marshall Spaceflight Center in Huntsville Alabama.