Numerical Solving of Radiation Geometrical Inverse Problem

Abstract

Compared to large satellites, on-board electronics of microsatellites, such as microprocessors, are more exposed to radiation and high-energy particles. This problem can lead to single-event upsets, which might generate false commands such as thruster firing or switching heaters on or off. In some cases, these upsets cause the loss of a spacecraft orientation and endanger the whole mission. This makes important to elaborate a reliable and robust attitude determination system which will enable us to correct and recover the spacecraft’s attitude after a failure. It must have a simple design, low mass, and power consumption. In this paper we suggest a new method of determination of spacecraft’s attitude based on heat fluxes analysis that could form the basis of such a system. In order to develop it we have to solve two inverse problems sequentially. The first inverse problem is the estimating of heat fluxes absorbed by the spacecraft surface. The second one is to determine the spacecraft’s attitude based on the estimated values of radiative heat fluxes. This paper is dedicated to the solution of the second inverse problem.