Mission Design for the CubeSat OUFTI-1

CHAPTER 9A typical layout of a Thermal Excel sheet is in figure 9.4: this is the operatingcase with black coating. As expected the absorption function has been updated.Figure 9.4: Typical Thermal Excel layout: operating case whit black coatingIn the other sheets, the conductive and radiative equivalent resistance arepassed.As expected, the hottest face is the one directed towards the sun and the coldestthose watching only the cold space. The face pointing the earth is in an intermediatecondition. An interesting point is that the temperatures of solar cellsand structure on a same face are almost the same, even if they seem equal. Forinstance, in black coated satellite in operating case we have for the face 1 thesolar cell at 272.623 K and the structure at 272.624 K. Anyway, for all practicalcases, we can consider them to be the same.In table 9.4 the results for different coatings and case are reported.Table 9.4: TemperaturesT0 MIN T INTERM T MAX TWHITE COLD CASE 236 K 236 K 236 K 236 KWHITE OPER. CASE 251 K 249.26 K 252.36 K 256.18 KWHITE HOT CASE 265.5 K 263.21 K 266.52 K 272.0 KBLACK COLD CASE 255 K 255 K 255 K 255 KBLACK OPER. CASE 275 K 272.62 K 276.13 K 283.60 KBLACK HOT CASE 287 K 284.04 K 287.83 K 296.99 KGOLD COLD CASE 266 K 266 K 266 K 266 KGOLD OPER. CASE 282 K 280.08 K 282.27 K 287.34 KGOLD HOT CASE 301.3 K 297.76 K 300.19 K 307.07 KWe can see that with a simple passive coating we can maintain the satellitetemperature within some reasonable limits.Galli Stefania 94 University of Liège