4 Final Report - Emits - ESA

4 Final
Report
Table 4.5-13: CPS Mass Budgets for considered options
Budget Element Option 1
Total CPS Dry Mass 162.9
Total residual 26.82
Total CPS EOL Mass 189.7
Useful Propellant load 1793.9
Total CPS BOL Mass 1983.6
4.5.7.2 EPS
The Electric Propulsion System (EPS) architecture is deriving from:
• Option 2: existing and available commercial solutions
• Option 3: iterations with AOCS definition and is the one used for most simulations of section
4.5.6 (Attitude and Orbit Control)
The necessary iterations with AOCS definitions are needed to optimise on board resources request
(power, mass, volume) while fulfilling mission requirements.
The architecture is summarised in the following table:
Table 4.5-14: EPS Architecture summary for the two options, Option 2 and Option 3
Option 2: EPS + MBW Option 3: EPS only
Main Manoeuvre Thruster (MMT) 2 main + 2 redundant
+ 2 thruster pointing mechanisms
8 main + 8 redundant
MMT Thrust 80 mN 30 mN
MMT Duty Cycle 100% during NSSK
85% during
manoeuvres (twice a day)
re-pointing manoeuvres
MMT PCU 1 main+1 redundant, each driving 2 2 PCU, each driving 4 main + 4
thrusters
redundant MMT
Fine Pointing Thruster (FPT) / 12 main + 12 redundant
FPT Thrust /
FPT Duty Cycle / 1% during fine pointing
FPT PCU / 2 PCU, each driving 4 main + 4
redundant MMT
EPS for Option 2
The EPS for Option 2 can be based on existing EPS for Eurostar 3000, with an architecture as per
Option 2 of Table 4.5-14, using SPT-100 as thrusters (HET type, 80 mN of thrust, 1510 s of Isp).
Doc. No: GOC-ASG-RP-002 Page 4-69
Issue: 2
Date: 13.05.2009 Astrium GmbH