Vzor optical orientator

The principle is simple and robust: through an annular belt of mirrors the cosmonaut sees the Earth's horizon all around the instrument. If the ship is correctly oriented the horizon forms an even ring, while the surface streams through the central field — its direction of motion shows which way the vehicle faces. Vzor was fitted to Vostok and Soyuz craft as a backup to the automatic system. Gagarin used it on the first flight, and manual descent through Vzor remained a standard emergency mode until the end of service. On display is the instrument with its porthole and reticle illumination.