Next came the outer suit. First there was the Lower Torso Unit, so-called, a bulky set of trousers with built-in boots. Arkady held the trousers steady while Henry swam into them.

And now Arkady held up the Upper Torso Unit, the top half of the suit, complete with built-in backpack and chest computer, lacking only gloves and helmet. Henry had to hold his arms up — the thumb loops dragged at his hands — and slither upwards into the suit, threading his arms into the bulky sleeves. The suit was filled by a stiff polyurethane pressure bladder; it took a real strain before he managed to pull his arms down by his side and force his head through the steel ring at the neck.

Arkady swam behind him, connecting umbilicals from the backpack to his undergarment. Then he showed Henry how to lock the two suit halves together; steel rings joined with faint clicks, and he pulled a fabric flap down over the joint.

Arkady lifted a Snoopy-hat communications carrier onto his head, and showed him the instruments mounted on his chest. “This is your display and control module. You see it has a LED display which will warn you of any malfunction. Here is how to adjust the oxygen flow inside your suit…”

Here came his gloves. There were a range of pairs in the lockers; he tried three or four before finding a pair which fit comfortably. The gloves fitted to his sleeves with a neat little snap-and-lock ring system. There were little rubber fingerpads, evidently to allow him to feel something of the world to which he was about to descend.

Last came the helmet, a plastic bubble with a snap-on gold-plated visor. There was a sound of closure as Arkady lowered the bubble over his head and snapped it into its place at his neck. He found himself looking out through a wall of plastic that was, he noticed, scuffed and starred, evidently by long use in Earth orbit.

Arkady showed him how to set the oxygen control switch on his chest to PRESS, and the suit built up an overpressure, so they could check for leaks.

His ears popped.

“The suit will preserve you,” Arkady said. Arkady’s face, peering in at him, was subtly distorted, the sound of his voice muffled, his words subtly masked by the gentle whoosh of air around his face. “It is good, mature technology, much better than the old Apollo suits. But you must anticipate problems. Remember the EMU has been designed for spacewalks in Earth orbit, not for Moonwalks. You may find the limbs stiff. And the suit is rather heavier than the Apollo design…”

Locked in here, it was hard to focus on what Arkady said. He flexed his joints and fingers; they seemed to move well.

He found he liked the suit, with its little glowing LED display and its snap-and-locks and flaps and zips. It had something of the feel of the interior of a quality car.