‘VZOR’ VSK-4 internal navigational periscope presumed to have been flown as part of the descent module of an early Soyuz spacecraft, measuring 14˝ in diameter and 12˝ in length. The VSK-4, or VZOR (meaning ‘sight’ or ‘vision’) was a fixed periscope with a simple optical system that projected an external view onto a marked grid visible to the crew inside the descent module. By aligning landmarks (Earth’s horizon, the Sun, stars, or other spacecraft) with the grid reticle, cosmonauts could check spacecraft attitude relative to known references, allowing them to manually orient the vehicle for rendezvous, docking, and reentry. Above the central 7˝ screen is the upper frame, which features four knobs for ‘Screen Contrast,’ ‘Shutter (on/off),’ ‘Peripheral Light Filter,’ and ‘Central Light Filter.’ The screen’s right frame bears the part number, “BCK4-CБ13 N011098903,” as does the bottom portion of the main mounting frame, “BCK4-CБ12, N011449802.” The VZOR is mounted on a wooden display base, 15˝ x 11˝ x 1˝, with an affixed nameplate. In fine condition.
Per the Soyuz Crew Operations Manual: ‘The VSK-4 has external and internal (cabin) parts which are installed on the window located in the descent module at the spacecraft ‘-Y’ axis…The external part consists of the central viewing tube and the peripheral tubing unit. The instrument line of sight can only be in two fixed positions: 0 degrees (“Ориент”) (Attitude Monitor) and 84 degrees (“Причал”) (Berthing). The position is changed by turning the mirror unit in the central tube head using an electric motor. The internal cabin portion includes the instrument body with elements of the two optical systems and the control knob panel…
Throughout the orbital flight, the crew uses the VSK-4 as the principal instrument for monitoring the spacecraft's attitude and attitude maneuvers for which the visor axis is set into the ‘Ориент’ position by КСП-Л В-18 command. The basic attitude-orbital Earth coordinate system (OCK) with preset heading angle is considered established when the reference object (Earth) apparent run direction in the central system field of view is parallel to the heading indicator stroke rotated at the preset angle. And the Earth horizon in the screen peripheral zone must be parallel to the corresponding strokes or coincide with them.
For approach/docking, the visor line is set in the ‘Причал’ position by the КСП-Л В-17 command. At a range of 2 km, the crew selects the screen according to the illumination conditions. In the shadow, the lens screen is used, and in the sunlight, the matte screen is preferable. At this range, it is possible to estimate the range using the screen grid.’
