SPACESUIT? Check. At least it looks like a spacesuit, with wire hoops sewn into the knee joints and substantial pockets for extraterrestrial rocks.

Boots? Check.

Gloves? Check.

Air supply? On.

Comms channel 2? Selected.

My head is bumping against the top of my helmet in a way that my fellow astronaut’s is not. He is clean-shaven and looks altogether more plausible under his Perspex dome. He grins encouragingly and presses a red button at the base of his helmet.

“This is EVA to Hab. Permission to enter airlock?”

There is a trill in my ear as he releases the button, then footsteps across the floor above us and a satisfying burst of static.

“This is Hab to EVA. Permission granted.”

We enter the airlock. A red light comes on in the ceiling. Depressurisation has begun. In 20 minutes it will be safe to step outside.

You can read about it, you can visualise it and you can watch 2001: A Space Odyssey as often as you like, but nothing quite prepares you for your first experience of interplanetary outerwear. It’s bulky without being heavy. One of the effects is a desire to walk in slow motion. Another is that you tend to forget it’s there and bump into things, especially indoors. It alters your voice, blows cool air across your nose and can induce self-consciousness in novices, even if there are no non-astronauts for 20 miles in every direction.

Or should that be 100 million miles? It might as well be. We are in a cylindrical space capsule designed to double as home for six astronauts for 18 months on the surface of Mars, and the view from the airlock’s porthole is of dry red soil hardened into hillocks. Behind us the ground rises to a low cliff. Away to the east there are dunes but also miniature mountains garnished with rocks. Nothing grows here. Everything is red or pink, except the sky, which is blue, and the two 350cc Kawasaki four-wheelers parked outside in the foreground, which are green.

We are, in fact, in an exceptionally secluded corner of southern Utah, which is an empty sort of place to start with. Ordinary earthly deserts stretch away on every side, but our own patch is extraordinary. For all that we know of Mars — and we suddenly know much more than we used to — this could be it.