SPACECRAFT PROPULSION - KTH

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- 31 -Table 4: Ranges of typical Propellant Tank Performance Factors-Kfor Liquid Propellant Tanks, [5]Type of Tank Average K*(10 4 m 2 /s 2 )Range(+/-1 sigma)(10 4 m 2 /s 2 )Remarks* Tank SafetyFactor: S = 2Diaphragm 2.25 1.53-2.97 Tank Material:Surface tension 3.32 2.28-4.36 Titanium AlloyNo propellant propellantmanagement device4.06 3.41-4.71 Ti 6Al4VBecause of the more energetic propellant hydrazine generating hotgas for mass expulsion, higher values of v e , and I ssp are achievedwhen compared with cold gas thrusters; see Table 5 below.Table 5: Performances of Actual Hydrazine Propulsion Systems(Listed data are examples and therefore only indicative)PROPELLANTTHRUSTERSPEC.-IMPULSEI sp (missionaverage)(Ns/kg)TOTALIMPULSEI tot(Ns)PROPUL-SIONSYSTEMMASSm PS(kg)SYSTEMSPEC.-IMPULSEI ssp(Ns/kg)REMARKSActual PropulsionSystemsI ssp values derivedfrom Ref. 10Monopropellant 2163 2.64 10 5 142 1859 ECSHydrazine: 2134 6.40 10 5 375 1707 ERS-1N 2 H 4 2110 9.50 10 4 66 1440 EXOSAT2110 6.41 10 4 38 1687 GEOSv e 2300 m/s; 2163 1.49 10 5 80.1 1860 GIOTTO = 1.0·10 3 kg/m 3 2163 7.25 10 4 48.8 1486 ULYSSES2168 2.36 10 5 130 1815 MARECS2060 8.24 10 4 53 1555 METEOSAT2168 3.04 10 5 168 1810 TELECOM-1N 2 pressurant gas,Max. op. pressure:p op =22 bar2150 − − 1781Calculated: I ssp fordiaphragm tank:C=0.75,K=2.310 4 m 2 /s 2 ,x = 6% (medium S/C)
- 32 -For comparison, a calculated I ssp -value for typical propellant storageand non-impulse system mass x, parameters are also presented inTable 5, showing an overall good agreement with I ssp -values of actualspacecraft propulsion systems.ConclusionMonopropellant hydrazine for spacecraft attitude and orbit control isone of the most widely used propellants. The primary reason for suchwide acceptance of monopropellant hydrazine propulsion systemslies in their inherent simplicity (reliability) while still providingadequate propulsive performance.ADVANTAGES:- simplicity and reliability (monopropellant);- lowest cost propulsion system (other than cold gas);- space storable for long periods (> 15 years demonstrated);- low thrust capability ( 0.5 N);- moderate thrust levels available ( 22 N).DISADVANTAGES:- moderate I sp ( 2300 Ns/kg) with moderate I ssp( 1900 Ns/kg) resulting in medium to high system mass;- limited life of catalyst.
Page 6 and 7: -iv -Standard NotationsStandard not
Page 8 and 9: - 1 -1 INTRODUCTIONThis booklet sum
Page 10 and 11: - 3 -The main features of jet propu
Page 12: - 5 -This expresses that the spacec
Page 17 and 18: - 10 -3.2.3 Evaluation of Mass of P
Page 19 and 20: - 12 -With regard to the system-spe
Page 21 and 22: - 14 -According to Fig. 3 and with
Page 23 and 24: - 16 -Historically, chemical propul
Page 25 and 26: - 18 -gases leave the outlet of the
Page 27 and 28: - 20 -The vaporising liquid system
Page 30 and 31: - 23 -Further, for vaporising liqui
Page 32 and 33: - 25 -ConclusionAlthough of moderat
Page 34 and 35: G- 27 -4.2.3 MonopropellantMonoprop
Page 36 and 37: - 29 -System-specific Impulse, I ss
Page 40 and 41: - 33 -4.2.4 BipropellantBipropellan
Page 42 and 43: - 35 -management devices), propella
Page 44 and 45: - 37 -From Eq. (41) it is obvious t
Page 46 and 47: - 39 -4.2.5 General System Design C
Page 48 and 49: - 41 -System-specific Impulse, I ss
Page 50 and 51: - 43 -4.3 Electric Propulsion4.3.1
Page 52 and 53: - 45 -To the above described catego
Page 54 and 55: - 47 -4.3.2 Propulsion System Desig
Page 56 and 57: - 49 -Fig.17, has to be considered
Page 58 and 59: - 51 -The term of an optimal exhaus
Page 60 and 61: - 53 -resulting in a maximum value
Page 62 and 63: - 55 -Table 8 notes the differences
Page 64 and 65: - 57 -5 PROPULSION SYSTEMS SELECTIO
Page 66 and 67: - 59 -m PS/m S/C1,0I ssp=193 Ns/kg(
Page 68 and 69: - 61 -In considering the merits of
Page 70 and 71: - 63 -Table 11: Survey: Typical Can
Page 72 and 73: - 65 -6.1 Potential Improvement of
Page 74 and 75: - 67 -6.2 Potential Improvement of
Page 76 and 77: - 69 -6.3 New ApproachesNew approac
Page 78 and 79: - 71 -Extensive research has been p
Page 80 and 81: - 73 -8 MISSION SURVEILLANCE OFPROP
Page 82 and 83: - 75 -[9 W. Inden; “Development R
Page 84: Notes

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