THERMAL MATHEMATICAL MODEL OF THE H-SHAPED BLOCK OF A NONHERMETIC INSTRUMENTAL COMPARTMENT OF A GEOSTATIONARY SPACECRAFTV. A. Burakov,a V. V. Elizarov,a E. N. Korchagin,b V. P. Kozhukhov,b A. S. Tkachenko,a and I. V. Shcherbakovaa UDC 629.78.048.7.001.24 A dynamic thermal mathematical model in distributed-lumped parameters, a computational algorithm, and a software of numerical calculations have been developed. The results of these calculations for multidimensional nonstationary temperature fields in operation of the on-board devices and a network of uncontrolled heat pipes in a nontraditional H-shaped block of the service-system module of a nonhermetic instrumental compartment of promising durable geostationary spacecraft under the conditions of orbital operation have been obtained. aScientific-Research Institute of Applied Mathematics and Mechanics at Tomsk State University, Tomsk, Russia; bAcademician M. F. Reshetnev Science and Production Association of Applied Mechanics, Zheleznogorsk, Russia; email: firstname.lastname@example.org. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 76, No. 4, pp. 142-149, July-August, 2003. Original article submitted May 6, 2002; revision submitted November 11, 2002.