Structural Design of The Brazilian Scientific Applications Satellite 1 (SACI-1)

This paper describes the structural design and analysis of the Brazilian Scientific Applications Satellite (SACI-1) that is devised as a multipurpose bus for scientific applications. The structure includes a Mainbody (Platform and Payload), an Adapter, four deployable panels and the holddown and release mechanisms (HDR). Its overall shape resembles a parallelepiped measuring 600 x 400 x 400 mm (Main body only) and weighting about 65 kg (Mainbody plus Adapter). The Platform consists on a pack of 9 aluminum ribbed frames of different thickness stacked horizontally and connected by means of 12 stud bolts. The Payload is assembled on the top of the Platform and has six ribbed plates that form a box in which most of the payload is assembled. The separation is accomplished by cutting (or releasing) one central rod that joins the Platform to the Adapter. The analysis of this structure was performed using a FEM model for static, normal modes, frequency response, transient response and random vibration analysis. With these results it was possible: (a) to verify the preliminary design of the structure and define the necessary changes; (b) to determine the first global frequencies of the assembly and; (c) to verify the accelerations on the printed circuit boards.