Features of Designing a Star Catalog for Orientation Sensors of Space Vehicles

Abstract—

A brief history of the creation of star orientation sensors at the Space Research Institute of the Russian Academy of Sciences (IKI RAS) and star catalogs for them is presented. An experiment carried out in the early 1970s on synchronous photography of stars and the Earth’s surface from the manned stations Salyut-2 and -3 is described. The difficulties of entering photographs into electronic computers (computers) of that time are shown. Based on the SAO, Hipparcos and Gaia star catalogs, about 11000 microcatalogs have been compiled around the brightest stars in the celestial sphere. Each of them contains in the center one star with a magnitude of up to 7.8^m and all the surrounding stars up to 13^m within a radius of 15′. The microcatalogs are combined into the “Basic Star Catalog,” which in the near future will be used to compile onboard star catalogs for the orientation sensors of the BOKZ family of spacecraft. To work with the base catalog, two programs have been developed and are used in test mode: Catalog Guide and Star Manager. The first program is designed to view the base catalog, visualize its fragments and compile lists of stars with specified parameters. The second program is of a computational and analytical nature. It contains mathematical models of star orientation sensors of the BOKZ family, as well as a mathematical apparatus that allows for detailed modeling of the most subtle elements of onboard data processing. Both programs can operate in manual and automatic modes. A sequence of actions worked out manually on several stars can then be performed automatically for large lists of stars. The article describes the structure and content of the base directory, and also illustrates working with it using programs specially developed for this purpose.