Search Results

Small satellites have been around since the dawn of the Space Age. Small, low cost satellites used to be the exclusive domain of scientific and amateur groups. Micro-Satellites fall into the 10–100 Kg category of Small Satellites. They are prone to single point failure and hence utmost care must be taken to design them with low safety factors. This paper gives the preliminary design procedure for a Micro-Satellite with subsystems. Here a Micro-Satellite has been modeled in CATIA and has been studied using ANSYS Finite Element Method codes. Initially the satellite was modeled for the static loads to be carried and after several iterations the optimized model to take dynamic loads with acceptable safety factor was obtained The Finite Element Model results have been validated with experimental results.

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%.

In recent years satellites of small sizes have been in development. Since electronic components are miniaturized and efficient, it is possible to develop satellite of small dimensions. The spirit of development of the small satellite in the world has been encompassed by the slogan “faster, better, smaller, cheaper”. The classes of satellite, which have the mass ranging from 10–100 kg, is called the micro-satellite. There are number of analysis like sensitivity analysis, vibration analysis, dynamic analysis and thermal analysis to be carried out in the development of the micro satellite both theoretically and experimentally. This paper discusses the free vibration analysis of a micro-satellite of mass less than 60kg. The micro satellite considered for this analysis is a spinning cuboids structure of 600mmx600mmx600mm dimensions with 18 subsystems positioned so as to meet the C.G and M.I. constraints.

The compression characteristics of thermoformable glass mat reinforcements with polyester binders have been studied as functions of temperature and platen closure rate. The mats were found to be more compliant and more compressible with increasing platen closure rate. At low closure rates, increasing the platen temperature has less of an effect on compressibility than at higher rates. Increasing the temperature also causes the mat to become more compliant. The compaction curves for the mats are described well with a logarithmic relation. This information is of interest to composite consolidation processes.

The effect of compaction and fiber volume fraction on the transverse permeability of a fluid flowing through stacked layers of fiber mats has been experimentally studied. A Unifilo-101 random mat of continuous glass strands, held together with a binder soluble in styrene was used. The stacked layers were compacted using a Wabash instrumented press. Changing the maximum load, resulted in different fiber volume fractions. Mixtures of glycerol and water with viscosities between 85 and 100 mPa-s were used. This fluid is passed in a rectangular cell, through the fibers arranged transverse to the direction of flow. The pressure drop across the mat and the flow rate were monitored. The study was carried out at different flow rates of the fluid and was repeated for other fiber volume fractions. A power-law relation was observed between the permeability and the fiber volume fraction.

This paper presents a study of the effects of a resin soluble thermoplastic preform binder on the Resin Transfer Molding (RTM) process. The focus of the study is the rate of dissolution of the binder in the resin and the associated viscosity changes in the resin. Tests on the rate of binder dissolution from continuous strand glass mats show that after one minute of exposure to styrene, roughly half of the medium solubility binder from Unifilo 750 will dissolve and all of the high solubility binder from Unifilo 101 will dissolve. As the concentration of binder in the resin increases from 0 to 5 wt. percent, the viscosity of a vinyl ester resin increases from 125 cps to 280 cps. The viscosity of the resin has also been monitored in continuous flow experiments through the mats placed in a rectangular plague mold, at different flowrates. In these runs, the viscosity varied from 245 mPa-s to 145 mPa-s when the fill time was 2.2 minutes.