Análisis De Comportamiento Térmico De Un Dispositivo De Asistencia Al Control De Actitud De Satélites

Abstract

The development of a system to assist the fly attitude control of satellites, based on
star images analysis, will be presented. The device, usually known as Star Tracker,
determines a position error signal, analyzing differences between two successive images of
previously identified star fields, on real-time. A Star Tracker aids the spacecraft CPU to
control fly parameters and maneuvers, providing a position reference system.
The device is integrated by a wide angular optic, a 510 X 492 pixel CCD camera with an
acquisition and storage image system and a DSP (Motorola DSP56F805) based CPU, all of
them prepared to operate in the aggressive space environment.
Parts will function in an aggressive vacuum (10-4 Torr) and temperature conditions (-34ºC
to 71ºC), then several simulations to estimate the device performance, thermal dissipation,
heat concentration and other important functional parameters had to be done.
SINDA/FLUINT® by Cullimore & Ring Technologies is a software package used by NASA.
This software tool was used to simulate the device thermal behavior under several conditions.
Design had to satisfy MIL-STD-1540 C “Test Requirements for Launch, Upper Stage, and
Space Vehicles”, and MIL-STD-1547B “Electronics Parts, Materials, and Processes for
Space and Launch Vehicles” standards, used by the European Space Agency.Design,
assembly and simulation criteria and other aspects of a Star Tracker fly model will be
discussed.