BURAN Orbital

Spaceship Airframe

Creation

Technology for Continuous Structures of Discrete Quartz Fibber

Prilepsky V.N.
Development stages of the process of manufacturing continuous structures from discrete quartz and experimental work on the Thermal Protection System’s (TPS) tiles are described. The necessity of quartz fiber dispersion to provide the maximum thermal resistance of heat protection composition is shown.

A composition, thoroughly investigated with application of theoretical methods of heat exchange on the basis of quartz fibers of about 1.5 … 2 microns diameter, which corresponds to the maximum thermal resistance of vacuumed dispersible environments, was taken as the basis of Thermal Protection System development.

As is known, the decreasing of fiber diameter results in an increase of its thermal resistance. It is explained by the increase of surface (number of screens on the way of a heat flow) at the change of fiber diameter. At dispersion of fiber, the heat flow is also reduced owing to the increase of evacuated air molecules collisions number that stipulates decreasing of heat conduction conductive component.

However, wherever the diameter of fiber is less than the length of thermal spectrum, so that the electromagnetic wave (according to the wave theory) is able to bend round the fiber, the composition becomes transparent to thermal spectrum. This explains existence of maximum thermal resistance along the fiber diameter and accordingly of minimum heat conduction.

At the first stage of quartz plates’ domestic production we were had to buy quartz fibers abroad in limited quantity. As a result of great activity, the essentially new way of obtaining discrete quartz fibers of continuous structures out of random agglomeration was proposed, which allowed to develop an original manufacturing method, in which all places of quartz fibers contacts are ‘welded’. In spite of the fact that only 5% of the material volume is taken by these fibers, there is a rigid framework, which strength exceeds the maximum values of loads, occurring during a flight at oscillating shock waves on the Orbiter’s surface and at its construction cooling in orbit.

The method of obtaining continuous structures from discrete quartz fibers was developed by NPO MOLNIYA (headed of work was V.N. Prilepsky).

A great contribution into this activity was made by employees of VNII BUMPROM (Paper Production Institute) and VNIISP(V) (Institute of Fiberglass Plastics and Fibers).

The method of the TPS tiles manufacturing was developed by VIAM under the guidance of Dr. Gribkov V.N. Large-scale work on exploration of the TPS tiles material properties, and realization of ground and flight tests of BURAN’s heat protection was accomplished at VIAM. The tiles’ undustrial production was mastered at NPO TEKHNOLOGIA under the guidance of Mr. Romashin A.G. Mr. Savin A.G., Mrs. Danilova E.N, Rakhimova T.A., as well as employees of NPO MOLNIYA Mr. Mordovin S.G., Davydov I.Z., Mrs. Tagunova L.I. made great contribution into this work, too.

The technique of obtaining quartz fibers was developed at VNIISP (V) under the direction of Mrs. Aslanova M.S. and Mr. Khazanov V.E. Besides, the industrial supply of fiber was accomplished by this institute.

As any porous body plates’ material can be intensively saturated with water from atmosphere. The questions of the tiles’ hydrophobic resistance before and after BURAN’s flight were successfully solved at:

VIAM (Mrs. Mukhanova E.E.) in cooperation with NPO MOLNIYA (Mrs. Tagunova L.I., Mr. Prilepskiy V.N., Zayko A.V.), institutes (belonging to Russian Academy of Sciences) - Institute of Chemical Physics (Dr. Leypunskiy I.O.), Institute of Organic Chemistry (Dr. Kazanskiy A.A.), and also Institute of Chemical Technologies of Elements-Organic Compounds (GNIIHTEOS).

For fastening tiles to orbiter’s skin, a glue composition on the basis of low-polymeric silicone rubber resin with an original catalyst of air drying (solidification), which ensured reliable tiles fixing in conditions of both series production of a manufacturing plant and test-ground. This technology was developed at VIAM under the direction of Dr. Batizat V.P. and Mrs. Petrova A.P. Active participation in industrial mastering of tiles gluing technique was taken by employees of NPO MOLNIYA Mrs. Klimovitskaya G.G. and Tagunova L.I.

Referred to the field of material science, the complex problem of obtaining erosion-resistant coatings on surfaces of porous heat-protective tiles was successfully solved. These coatings (‘black’ and ‘white’) perform a number of functions: ensure the necessary radiation value of tiles’ surfaces, their humidity resistance, heat resistance, poor catalytic activity in reactions of oxygen and nitrogen atoms recombination. The technology of production and application for these coatings was developed at VIAM (Dr. Bersenev A.Yu. and Mrs. Isaeva N.V. under the direction of Dr. Solntsev S.S.).

Employees of NPO MOLNIYA Mrs. Yeremina A.I., Mr. Barabanov B.N., Bogdiun G.N., and Mrs. Dudova S.V. took part in the studying on coatings’ operation properties.

A matter of principal was provision of heat protection tiles’ resources and resistance against thermal-chemical and heat degradation (aging). In order to solve this problem, a great experimental work was accomplished on the thermal-vacuum, thermal-mechanical and vibration test beds in TsAGI, as well as on the induction plasmatrons (Institute of Mechanics Problems, from Russian Academy of Sciences, and TsNIIMASH). The indicated requirements were met.

By results of ground running, the created BURAN’s thermal protection is serviceable for hundred flights.

Teams of Institute of High Temperatures (IHT - from Russian Academy of Sciences - Dr. Petrov V.A. and Dr. Reznikov V.Yu.) and TsAGI (Dr. Paderin L.Ya. and Dr. Zhestkov B.Ye.) took active participation in experimental study on BURAN’s heat protection properties. It is necessary to make a special note on a complex of works, carried out at Institute of Mechanics Problems (Dr. Yakushin M.I., Kolesnikov A.F., Gordeev A.N. and Mrs. Mysova V.M.) in cooperation with NPO MOLNIYA (Mr. Voinov LP., Prilepsky V.N. and Zaiko A.V.).

As a result of this research, the experimental-theoretical model of air plasma interaction with the surface of orbital spaceship was created.

Development of design-engineering documentation on thermal protection for BURAN and the works on its tests according to the complex program of experimental running were performed by employees of NPO MOLNIYA (Dr. Gofin M.Ya., Mr. Goryachev A.S., and others, under the general direction of Mr. Mordovin S.G.