4 Final Report - Emits - ESA

More documents

Recommendations

Info

4 Final Report The primary structure design is founded on the E3000 heritage design. The central structure consists of a lower conical section and two upper cylinder segments. With the exception of the Aluminium Alloy upper ring segment all other parts are made from filament wound CFRP sandwich panel section. Bonded rings are located at each end of the CFRP cone cylinder and at the intersection between the cone and cylinder. Considering each of these rings the lower ring provides the launch vehicle adapter (LVA) interface, through this ring interfacing with an opposite ring on the launch vehicle, combined with the use of a clamp band, the launch vehicle interface is made. The at the cone cylinder junction supports the tank floors, to this an important part of the central structure, the tank support struts, linking this floor at the tank interfaces to the LVA ring, these provide axial support to the tank. The upper tank floor, which provides lateral support only allowing tank expansion, mounts to the ring at the top of the cylinder. Focusing on E3000 heritage all shear wall and tank floors are made from Aluminium alloy sandwich panels. If future, more detailed, distortion analyses would show the need for a CFRP panels, the material of the shear walls could be switched from aluminium skin to CFRP skin but retaining the Aluminium alloy honeycomb core. Secondary Structure The satellite secondary structure consists of, • ±Z equipment panels and ±Y closure panels • Local support brackets/panels as e.g. − Connector brackets − Thruster supports − EMC covers − Liquid apogee engine and pressurant tank supports − etc. Focusing on E3000 heritage the equipment panels are made from Aluminium alloy sandwich panels. Currently proposed is the use of CFRP skinned panels, however if future, more detailed, distortion analyses would show that Aluminium Alloy panels could be accommodated, the material of the equipment panel walls could be switched from CFRP to aluminium skin but retaining the Aluminium alloy honeycomb core. The panel thickness will be typically 35-40mm. The design and the materials of local support structures will be defined in a later project phase. Solar Array The solar array substrate will be a lightweight CFRP sandwich panel with typically 20 mm thickness. Structure Load Paths The circular central structure will collect the individual loads over its height and will ensure a homogeneous load distribution over the launcher interface circumference. Hence the launcher I/F overflux requirement will be fulfilled. The axial (in-plane) equipment panel loads will be transferred to the central cylinder via the shear webs. Page 4-74 Doc. No: GOC-ASG-RP-002 Issue: 2 Astrium GmbH Date: 13.05.2009
4 Final Report The lateral in-plane equipment panel loads will be transferred to the central cylinder via the floors in shear. The lateral out-of-plane equipment panel loads will be transferred to the central cylinder via the shear webs and floors in tension/compression. The tanks are grouped closely around the central structure. Thus the tank load path is very short and mass-effective, the tanks will laterally be supported by the tank floors and axially by struts from the lower tank boss to the LVA ring side. CFRP Outgassing Water and carbohydrate evaporation in the vicinity of the instruments needs to be limited to avoid e.g. ice on cold optical surfaces. Any critical CFRP surface shall be sealed by an aluminium barrier foil of typically 20 microns. In the past, this was done successfully e.g. on all inner surfaces of the 6.8 m long XMM telescope tube structure. Distortion Assessment Pointing stability depends on thermal and moisture release distortions and therefore on configuration, material selection, method of construction, changes in average temperature and temperature gradients. A similar stringent requirement also exists for MTG. It is therefore assumed that, through the high degree of similarity between the two satellites, that the Geo-Oculus environment would yield distortions of similar magnitude. Therefore, it is confidently believed that distortions should not be an issue for Geo-Oculus. Launch Vehicle Vibrations The Frequency requirements for the S/C hard mounted at the I/F to the launch adapter are taken from Soyuz since it is the worse case compared to Ariane 5: • 15 Hz in lateral + 15% margin • 35 Hz in longitudinal + 15% margin Considering stiffness the main driver for the fist axial frequency is tank mass and the stiffness of the underlying support. To optimise stiffness performance the heavy and light tanks are diagonally opposite as to maintain a central centre of gravity position, also the supporting struts are categorised into heavy or light struts each providing the best support stiffness for the respective tank mass. The first lateral mode is largely driven by the X axis centre of gravity position, this is heavily influenced by the mass of any +X top floor mounted equipments and instruments. To estimate the first lateral frequencies of the Geo-Oculus spacecraft, the performance of the reported performance of MTG spacecraft has been examined and scaled as appropriate. Scaling has taken account of the comparative propellant mass and instrument mass associated with the Geo-Oculus spacecraft. The MTG spacecraft is viewed as a suitable foundation given the spacecraft architecture is similar to Geo-Oculus and likewise is largely based on E3000 heritage, the most significant differences is an extra 150kg approx located on the spacecraft +X floor and an extra propellant mass of 178Kg. The first lateral and longitudinal frequencies are as follows, Doc. No: GOC-ASG-RP-002 Page 4-75 Issue: 2 Date: 13.05.2009 Astrium GmbH
Page 1:
Geo-Oculus: A Mission for Real-Time
Page 7:
DL Final Distribution List Report Q
Page 11 and 12:
TOC Final Table of Content Report D
Page 13 and 14:
1 Final Report 1 Introduction 1.1 S
Page 15:
1 Final Report [RD 7] Candidate Mis
Page 18 and 19:
2 Final Report capability of existi
Page 20 and 21:
2 Final Report Figure 2.3-1: Flood
Page 22 and 23:
2 Final Report Figure 2.3-3: Algal
Page 24 and 25:
2 Final Report Figure 2.3-6: Chloro
Page 26 and 27:
2 Final Report Erosion / Sediment T
Page 28 and 29:
3 Final Report 3 System Requirement
Page 30 and 31:
3 Final Report Furthermore, the mis
Page 32 and 33:
3 Final Report better than 0.5 SSD
Page 34 and 35:
3 Final Report • Image post integ
Page 36 and 37:
3 Final Report Table 3.3-1: Baselin
Page 38 and 39:
3 Final Report Manoeuvre Times and
Page 40 and 41: 3 Final Report Cloud Amount [%] Num
Page 42 and 43: 3 Final Report cloud scenes where t
Page 44 and 45: 4 Final Report Alternative solution
Page 46 and 47: 4 Final Report The achieved ground
Page 48 and 49: 4 Final Report board image processi
Page 50 and 51: 4 Final Report 4.3.3.2 UV-VNIR foca
Page 52 and 53: 4 Final Report Column decoder 4 out
Page 54 and 55: 4 Final Report 4.3.3.5 Mechanical a
Page 56 and 57: 4 Final Report 4.3.3.7 Electrical a
Page 58 and 59: 4 Final Report 4.3.4 PLM budgets Th
Page 60 and 61: 4 Final Report 4.4.2 Microvibration
Page 62 and 63: 4 Final Report Figure 4.4-2: Struct
Page 64 and 65: 4 Final 4.5 Satellite Report 4.5.1
Page 66 and 67: 4 Final Report Star Tracker Figure
Page 68 and 69: 4 Final Report (Spacecraft Computer
Page 70 and 71: 4 Final Report This is based on a w
Page 72 and 73: 4 Final Report Reception of the ins
Page 74 and 75: 4 Final Report Table 4.5-2: Charact
Page 76 and 77: 4 Final Report Table 4.5-4: Compari
Page 78 and 79: 4 Final Report Table 4.5-5: EPS fue
Page 80 and 81: 4 Final Report manoeuvre. It also h
Page 82 and 83: 4 Final Report Figure 4.5-10: Basel
Page 84 and 85: 4 Final Report The CPS considered f
Page 86 and 87: 4 Final Report PPU B* FU XST Page 4
Page 88 and 89: 4 Final Report Table 4.5-17. EP mas
Page 92 and 93: 4 Final Report Direction MTG Scaled
Page 94 and 95: 4 Final Report 4.6.1.1 High Level F
Page 96 and 97: 4 Final Report shorter. As a conseq
Page 98 and 99: 4 Final Report 4.6.2.4 Cloud Cover
Page 100 and 101: 4 Final Report management functions
Page 102 and 103: 4 Final Report 4.6.2.8 Ground Stati
Page 104 and 105: 5 Final Report based on EUMETSAT im
Page 107 and 108: A Final Report Annex A Abbreviation
Page 109 and 110: A Final Report ICU Instrument Contr
Page 111: A Final Report Doc. No: GOC-ASG-RP-
show all

4 Final Report - Emits - ESA

Create successful ePaper yourself

Delete template?

Save as template?