Master Thesis - OUFTI-1

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of other signicant components of the satellite, which is precisely the case of the battery support. For availability reasons, the Al − 7075 T 6 alloy was selected [40]. 3.7 Thermal control's devices selection Now, the selection of the dierent devices that perform the thermal control of the batteries, will be discussed. It should be noted that this selection was realized by the THER team. Further detail on each of these devices can then be found in reference [35]. In this section, we will only draw a list of these components and, for each of them, the advantages that led to this particular choice. 3.7.1 Heaters To maintain the batteries' temperature range in acceptable values, the use of heaters is necessary. In our case, the heaters are polyimide thermofoil heaters from Minco industry (illustrated in Figure 3.10) [41]. Figure 3.10: Polyimide thermofoil heater These heaters present several advantages: • They are available in a lot of dierent forms and dimensions. In our case, we chose heaters that had the dimensions closest to the batteries' ones. • They are lightweight. • They can be glued directly on the batteries. This particularity is widely used in space applications. • They are space-qualied. 55
The last property to determine is the value of the resistance. Thermal simulations performed last year [12] allow to determine that the power necessary to heat the batteries, is 250 mW . Assuming that heaters are supplied by a tension of 2.5 V (which is a conservative approach because the tension of the batteries can not pass under 2.7 V ), the resistance can be easily calculated (see Equation 3.7.1). P = U I = U 2 R ⇒ R = U 2 P = 2.52 = 25 Ω (3.7.1) 0.25 The available heater that is closest to this value is a heater with a resistance of 23.7 Ω, which is again a conservative approach because the power generated will be higher than 250 mW . The heaters will be glued, as already mentioned, directly on the batteries, on their face +Z (which corresponds to the side of the box). 3.7.2 Heaters' control system Two solutions were investigated to realize the heaters' control system: • Creation of an electrical circuit that used heat sensors to decide when the heaters have to be supplied. • A thermostat that is self-ecient. In accordance with the KISS philosophy, the second solution was preferred because it is more reliable. The selected thermostats are Klixon 4BT − 2 [42], illustrated in Figure 3.11 (the dimensions are given in inches). Figure 3.11: Thermostat Klixon 4BT − 2 56
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University of Liège Faculty of App
Page 3 and 4:
Abstract OUFTI-1, standing for "Orb
Page 5 and 6: 3.4 Initial idea . . . . . . . . .
Page 7 and 8: List of Figures 1.1 The Pumpkin's C
Page 9 and 10: 4.18 MAC matrix using the simple me
Page 11 and 12: List of Acronyms ADCS Al AlNiCo ASI
Page 13 and 14: Thesis outline This thesis focuses
Page 15 and 16: of larger satellites. So, the CubeS
Page 17 and 18: 1.2 OUFTI-1 project 1.2.1 Genesis O
Page 19 and 20: • XatCobeo (Vigo - Spain): Develo
Page 21 and 22: Chapter 2 OUFTI-1: Flight system co
Page 23 and 24: Figure 2.2: Product tree of OUFTI-1
Page 25 and 26: 2.3.2 Solar panels The armor panels
Page 27 and 28: • We do not want to drill or manu
Page 29 and 30: In our case, because of the limited
Page 31 and 32: Figure 2.13: Magnetic eld obtained
Page 33 and 34: Figure 2.17: Pictures of the ADCS c
Page 35 and 36: consider the possibility of oshorin
Page 37 and 38: Figure 2.20: Exploded view of OUFTI
Page 39 and 40: I xx , I yy and I zz are called the
Page 41 and 42: Subsystem: Structure & Conguration
Page 43 and 44: Subsystem: Thermal Control Parts Co
Page 45 and 46: Chapter 3 Design of a new support f
Page 47 and 48: Figure 3.3: Batteries during and af
Page 49 and 50: The concept is the following one: F
Page 51 and 52: A test under vacuum conditions was
Page 53 and 54: Thermal Expansion (CTE) of the mate
Page 55: Figure 3.9: Classication by density
Page 59 and 60: • So, it was decided to use two t
Page 61 and 62: is to prevent the batteries' bulge.
Page 63 and 64: • Then, the thermostats, that wil
Page 65 and 66: Figure 3.23: Schematics of the cove
Page 67 and 68: • Other components, including the
Page 69 and 70: 3.9.3 Dynamic behavior Finally, it
Page 71 and 72: 3.10 Summary Through this chapter,
Page 73 and 74: Chapter 4 Electronic cards dynamic
Page 75 and 76: Figure 4.1: Example of manufacturin
Page 77 and 78: Figure 4.4: Illustration of the exp
Page 79 and 80: Figure 4.5: MAC between the two mod
Page 81 and 82: • Global mass/stiness smearing me
Page 83 and 84: 4.2.6 Modeling of the chassis A gen
Page 85 and 86: Q = ω k = 1 ω b − ω a 2 ζ ⇒
Page 87 and 88: Their study was based on the fact t
Page 89 and 90: Figure 4.14: Example of spacecraft
Page 91 and 92: Figure 4.15: Location of measuremen
Page 93 and 94: Figure 4.18: MAC matrix using the s
Page 95 and 96: 4.3.6 Application of the local mass
Page 97 and 98: ρ P C 104 connector = 10.12 × 10
Page 99 and 100: According to this particular shape,
Page 101 and 102: This is due to the fact that this c
Page 103 and 104: environment. Then, this model is ex
Page 105 and 106: 5.2.4 Antenna support For the anten
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Components Young's moduli (GP a) Po
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Components Young's moduli (GP a) Po
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5.3 Static analysis As described in
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Figure 5.9: Illustration of the com
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Figure 5.11: Maximal Von Mises stre
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Figure 5.12: First mode of OUFTI-1
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Figure 5.15: Precise PSD of Vega [5
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Chapter 6 Conclusions This master t
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provided for each method used. We h
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last versions of the Verication Con
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[13] Ph. LEDENT. "Design and Implem
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[40] "Dejond - Aluminum Catalog ".
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Appendix A Schemas of solar panels
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Appendix B Schemas of electronic ca
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Appendix C Fixations of the endless
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Appendix D Datasheet of the battery
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Master Thesis - OUFTI-1

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