4 Final Report - Emits - ESA

4 Final
Report
Table 4.5-17. EP mass budget for Option 3 [kg]
Fine Pointing
Thruster
Table 4.5-18. EP power budget for Option 3 [W]
Fine Pointing
Thruster
Main Manoeuvre Thruster
HEMPT GIT
GIT 860 902
FEEP 834 876
Main Manoeuvre Thruster
HEMPT GIT
GIT 2571 2138
FEEP 2600 2167
4.5.7.3 Propulsion System Summary
The mass of the propulsion system for the three options is summarised in Table 4.5-19.
Option 3 is not practical since too massive, complex and expensive. Option 1 is the traditional
configuration and is feasible. Option 2 allows to save between 250 and 340 kg (depending on the
selected technology) on Option 1 by using EP for station-keeping. However, this mass reduction
should be somewhat reduced as it does not take into consideration the additional mass due to an
increase in solar array as well as batteries, and potentially PCDU too. An in-depth analysis would be
required at a later stage to determine the better of Options 1 and 2.
Table 4.5-19. Geo-Oculus propulsion options summary
S/C dry mass (no PS)
EPS dry mass
CPS dry mass
TOTAL PS DRY MASS
EPS Total Prop. load
CPS Total Prop. load
TOTAL PROP. LOAD
TOTAL PS MASS AT LAUNCH
Power requirements [W]
Option 1
1668.3
/
189.7
189.7
/
1793.9
1793.9
1983.6
/
Option 2
HET
1668.3
92.8
157.2
250.0
83
1404.2
1487.2
1737.2
2895
4.5.8 Structure and Thermal Concept
4.5.8.1 Structure
Option 2
HEMPT
1668.3
103.2
133.8
237.0
41.1
1364.4
1405.5
1642.5
6619
Option 3
HEMPT+FEEP
1668.3
287.4
189.7
477.1
573.9
1838.3
2412.2
2889.3
Option 3
GIT+GIT
1668.3
354.4
194.3
548.7
578.2
1888.0
2466.2
3014.9
2138
Page 4-72 Doc. No: GOC-ASG-RP-002
Issue: 2
Astrium GmbH Date: 13.05.2009
2600
Option 3
HEMPT+GIT
1668.3
311.7
189.7
501.4
576.3
1857.7
2434
2935.4
2571
Option 3
GIT+FEEP
1668.3
330.1
189.7
519.8
575.6
1869.5
2445.1
2964.9
Structure design
Figure 4.5-13 depicts the structure of the satellite with 4 propellant tanks, based on Astrium’s Eurostar
2167