Preliminary Design and Vibration Study of Micro-Satellite Structure

The capabilities of micro satellites continue to grow more sophisticated with each passing year, allowing them to be used to carryout different types of missions those once required with much large satellite platforms. The miniaturization of electronic components enabled to develop satellites of small size, ranging 10–100 kg. The benefits of developing the micro satellite leads to shorter development times and much lower costs than for larger satellite while achieving high levels of performance and capability. This paper summarizes the preliminary design, i.e. selection of suitable structural configuration and vibration analysis of a micro satellite structure of mass not exceeding 50kg. The envelope allowed for the satellite as a secondary payload by polar satellite launch vehicle is 600*600*600 mm³. Since it is a spinning satellite having spin rates between 4 to 8 rpm, the Moment of Inertia about the spinning axis should be greater than other two axes by at least 11%. To meet the above constraints, a micro satellite of a cuboids structure was selected with three deck plates, three cross webs between bottom and middle decks, four vertical webs between middle and top decks, 28 subsystems arranged on above and below the middle deck and also on the cross webs. As per the frequency constraints imposed by the launcher on the micro satellite lateral frequency should be greater than 45 Hz and longitudinal frequency should be greater than 90 Hz. The Aluminum honeycomb sandwich panels were considered as the preliminary type of construction for the analysis with Aluminum alloy angles as the joining members between the various structural members. To model the micro satellite structure with subsystem and to analyze, commercially available Finite Element Analysis (FEA) software ANSYS was used. Analysis was carried out for the basic structure and with the subsystems to find whether the configuration satisfies the above constraints mentioned. The vibration analysis was also made by changing the deck plate thickness. The above analysis was made to improve the micro satellite configuration for other analysis.