Linearized techniques for solving the inverse problem in the satellite thermal control

The design of the passive temperature control on a spacecraft is generally based on the tentative assignment of the thermo-optical parameters, on the computation of the corresponding temperatures and, then, on a correction pr ocedure based on a locally linearized "sensitivity". In this paper, instead of this classical approach, we try a method that, still on a linearized ba sis, uses the pseudoinverse of the temperature Vector to realize the wished temperature in the structure. The solution of the problem uses the definit ion of null space and pseudo-inverse and the matrix of the unknown is deter mined in such a way that the physical characteristics of the coupling radia tive and conductive matrix (that means symmetry and balance) are satisfied. Other constraints shall be imposed, and at the end, when the number of unk nowns is equal to the equations, the problem is solved. Due to the arbitrar iness in the additional constraints needed for closing the problem, the sol ution obtained with this method is not unique. It is possible in any case t o choose optimized solutions as, for-instance, the easiest to be realized i n practice. (C) 1998 Elsevier Science Ltd. All rights reserved.