I woke up. Dark. Looked at my “Elektronika” watch; the backlight is weak, I could barely make out the time — 4 AM. Apparently when I was filling the “Oasis” container with water yesterday, my hands got wet and the watch crystal started fogging. In short, this watch is not made for space.

I tried to fall back asleep twice — more like dozed — and woke up around 8. Got up, if you can call it that. More precisely, I floated out of the sleeping bag, made a left turn over my shoulder, oriented myself properly in the station, and glided to the primary post. Came on the air.

The ground asked us to switch to the second loop of the thermal control system. Tolya was sleeping. I spoke with Zhenya Kobzev.

Before lunch we pumped water from the cargo ship into the station’s tanks. We now have plenty of water — 300 liters taken aboard. Then we stowed the delivered equipment and continued the inventory.

By the end of the day my mood lifted. We went to the transfer compartment to measure atmospheric refraction by the stars. I could see it interested Tolya.

Yes, about our orientation in the station. We float in the position we’re accustomed to living in: where the table is, that’s the floor; above it is the ceiling; to the right and left are walls. This terrestrial layout holds only in the work compartment. In the transfer compartment, the layout was dictated by the observation requirements — there are seven portholes around the perimeter. So you drift into the transfer compartment and start rotating from one porthole to the next, choosing the best one and finding a comfortable position for observing and shooting. Naturally, you disengage from your surroundings, stop tracking your own position in the compartment, and rotate only relative to the Earth and the stars. And if at that moment you need something — a camera, maps, a logbook, an instrument — you can’t immediately tell where you are, what position you’re in, where up is, where down is, which plane is which. You start mentally reconstructing your orientation from the compartment details, or you look along the station interior. And sometimes you finish your observations and have spun around so much in the process that instead of going through the hatch into the station you end up in the transport ship. Or you glide into the work compartment in some odd attitude — the table is off to the side, everything looks different — but you latch onto something visually, the control panels, some element of the interior, and once you grasp the relationship between their positions, you begin rotating yourself relative to them until you settle into the familiar, normal position. Although here any position can be “normal” — whether you’re standing on the ceiling with your feet or walking on the walls. You just need to recalibrate your perception, telling yourself: the wall is the floor; everything above it, over there, is the ceiling. Just look forward, into the perspective, and accept this view as the new interior. Now everything is fine: you’ve reoriented and feel no discomfort from walking on a wall or a ceiling.

This particular feature of weightlessness will undoubtedly be used in the architecture of future orbital and interplanetary crewed systems, where the layout within a single volume of living and working spaces may employ “wrap-around interiors to create a variety of functional and aesthetic compositions.”