SPACECRAFT PROPULSION - KTH

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- 59 -m PS/m S/C1,0I ssp=193 Ns/kg(Nitrogen)Cold GasI ssp=654 Ns/kg(Ammonia)I ssp=1440 Ns/kgHydrazineI ssp=1860 Ns/kg0,8I ssp=2356 Ns/kgBipropellantI ssp=2746 Ns/kg0,6I ssp=5980 Ns/kg0,4SPT/Ion ElectricPropulsion Systems0,2I ssp=11980 Ns/kg0,0500 1000 1500 2000 2500 3000NITROGEN (1PROPANEHYDRAZINEPACTdelta-v (m/s)Figure 20: Delta-V Performance Range of Spacecraft Propulsion System Concepts (Examples)
- 60 -The diagram in Fig. 20 gives the first and most important indicationfor the selection of propulsion systems. If we assume a system massratio of m PS /m S/C < 0.30, we can read directly from Fig. 20:- for low v 150 m/s, compressed cold gas and vaporising liquidpropulsion systems seem to be the best choice, because they meetthe requirement and have the lowest cost;- for 150 v 650 m/s, monopropellant hydrazine fed propulsionsystems are the best choice, because of their inherent simplicity(reliability) and potential low cost, while still meeting the Δvrequirement;- for high v 650 m/s, bipropellant systems, monopropellanthydrazine fed resistojet systems (power-augmented thrusters,arcjets), and electrostatic (electromagnetic) systems will satisfy thev-requirements best.Finally, for any given value of total impulse I tot , the mass of thepropulsion system m PS can be calculated of course directly fromvalues of I ssp .When a suitable spacecraft auxiliary propulsion system is selected,however, the cost, complexity, operability and reliability of thesystem also play an important role.With regard to low v-requirements, compressed cold gas systemsused for auxiliary propulsion of spacecraft’s (attitude and orbitcontrol), although of moderate impulse capability, are still of interestin view of their simplicity, high reliability, repeatability of impulsebit and low system costs.
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 38 and 39: - 31 -Table 4: Ranges of typical Pr
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 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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SPACECRAFT PROPULSION - KTH

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