Internal Final Presentation …sgo.caltech.edu/lib/exe/fetch.php?media=07_eulisa_chemical...EuLISA – Assessment Study Chemical Propulsion - 2 Option 1

<Chemical Propulsion> Internal Final Presentation ESTEC, 8 July 2011 Prepared by the ICPA / CDF* Team

EuLISA

(*) ESTEC Concurrent Design Facility

Chemical Propulsion - 2 EuLISA – Assessment Study

Option 1

• First table in MA presentation: Delta-v budget LGA transfer, double launch


Option 1 •  Mother Spacecraft: 1184 kg (dry mass) •  Daughter Spacecraft: 811 kg (dry mass)

•  Calculate propellant amounts to generate the required ΔVs •  Assume margins

•  Propulsion system trade off: Monoprop vs Biprop monopropellant resulted in a lighter system (but also cheaper, cheaper to test, etc.)

Additional requirements: •  Preferably European COTS components •  (LISA Pathfinder propulsion module: biprop system with Eurostar

2000 derived tanks) •  Single fault tolerant system design


Delta-v budget LGA transfer, double launch

mother daughter 1 daughter 2

launcher disp 36m/s 5m/s 5m/s

perigee raise - 40m/s 40m/s

plane change - 11m/s 80m/s

apogee raise - 40m/s 40m/s

arrival 154m/s 130m/s 104m/s

navigation 20m/s 20m/s 20m/s

launch window reserve, gravity loss (20%)

42m/s 46m/s 50m/s

total 252m/s 272m/s 299m/s


Mother S/C option 1 MASSESSpacecraft DRY MASS 1184 [kg]

ENGINE CHARACTERISTICS

Propulsion type MonopropName Hydrazine [-]Propellant density 1010 [kg/m3]

Thrust level [N]Number of engines [-]Isp 220 [s]Mass [kg]Mass flow rate [kg/s]

VELOCITY INCREMENTS INCLUDING MARGINSum of main delta V including margins 264.6Steering / AOCS lossed during main Delta V 25.2Velocity increment (INCLUDING MARGINS) 289.8 [m/s]


Mother S/C option 1 PROPELLANT CALCULATIONS

Total propellant for alll velocity increments (including margins excluding residuals) 170.2 [kg]Additional AOCS propellant 2.0 [kg]

Total propellant for alll velocity increments (including margins including residuals) 176 [kg]

NUMBER OF TANKS 2 [-]

Propellant mass per tank including margins and residuals 87.8 [kg]

Percentage of maximum capacity 68 [%]

Propellant volume per tank 0.087 [m3]Total propellant volume 0.174 [m3]

Note: Herschel tanks


Mother S/C option 1

Note:

Herschel tanks


Mother S/C option 1 Element 2 Mother S/C

Unit NameClick on button above to insert

new unit1 5 N thruster (MONARC-5 of AMPAC ISP) 8 0.5 Fully developed 5 4.12 20N thruster (CHT-20 of ASTRIUM) 8 0.4 Fully developed 5 3.23 Propellant tank 2 15.500 Fully developed 5 32.64 Propellant filter 1 0.300 Fully developed 5 0.35 Latching valve 2 0.700 Fully developed 5 1.56 Pressure transducer 3 0.280 Fully developed 5 0.97 Fill and Drain valve / Vent valve (propellant) 2 0.070 Fully developed 5 0.18 Fill and Drain valve / Vent valve (pressurant) 4 0.070 Fully developed 5 0.39 Piping (incl fittings) 0.1 35.000 To be developed 20 4.210 Stand-off 110 0.022 To be developed 20 2.911 Mounting screws 1 0.840 To be developed 20 1.012 Miscellaneous 1 0.100 To be developed 20 0.113 Pressurant 1 1.500 Fully developed 5 1.6-

13 49.3 7.1 52.8

MASS [kg]Unit Part of custom

subsystemQuantity Mass per

quantity excl. margin

Maturity Level Margin Total Mass incl. margin

Click on button below to insert new unitSUBSYSTEM TOTAL

176 kg propellant (Hydrazine)


Daughter S/C option 1 MASSESSpacecraft DRY MASS 811 [kg]

VELOCITY INCREMENTS INCLUDING MARGINSum of main delta V including margins 313.95Steering / AOCS lossed during main Delta V 29.9Velocity increment (INCLUDING MARGINS) 343.9 [m/s]PROPELLANT CALCULATIONS

Total propellant for alll velocity increments (including margins excluding residuals) 140.1 [kg]Additional AOCS propellant 2.0 [kg]

Total propellant for alll velocity increments (including margins including residuals) 145 [kg]


Daughter S/C option 1

Smaller Seastar tank possible:

NUMBER OF HERSCHEL TANKS 2 [-]




NUMBER OF SEASTAR TANKS 2 [-]





Daughter S/C option 1

Note:

Seastar tanks


Daughter S/C (option 1) Element 1 Daughter S/C


new unit1 5 N thruster (MONARC-5 of AMPAC ISP) 8 0.5 Fully developed 5 4.12 20N thruster (CHT-20 of ASTRIUM) 8 0.4 Fully developed 5 3.23 Propellant tank 2 8.200 Fully developed 5 17.24 Propellant filter 1 0.300 Fully developed 5 0.35 Latching valve 2 0.700 Fully developed 5 1.56 Pressure transducer 3 0.280 Fully developed 5 0.97 Fill and Drain valve / Vent valve (propellant) 2 0.070 Fully developed 5 0.18 Fill and Drain valve / Vent valve (pressurant) 4 0.070 Fully developed 5 0.39 Piping (incl fittings) 0.1 35.000 To be developed 20 4.210 Stand-off 110 0.022 To be developed 20 2.911 Mounting screws 1 0.840 To be developed 20 1.012 Miscellaneous 1 0.100 To be developed 20 0.113 Pressurant 1 1.500 Fully developed 5 1.6-

13 34.7 8.0 37.4SUBSYSTEM TOTAL

Mass per quantity excl.

margin

Click on button below to insert new unit

MarginPart of custom subsystem

Total Mass incl. margin

Unit Quantity Maturity LevelMASS [kg]

145 kg propellant (Hydrazine)


-


Not considered option

• Second table in MA presentation: Delta-v budget direct transfer, double launch


Not considered option •  Mother Spacecraft: 1184 kg (dry mass) 252 m/s

•  Propulsion module for 2-Daughter Spacecraft •  Payload 2 Daughter s/c of 811 kg each (+ propellant) 788 m/s

Then

•  Daughter Spacecraft: 811 kg (dry mass) 252 m/s

•  Calculate propellant amounts for required ΔVs. •  Assume margins

•  Propulsion system trade off: Monoprop vs Biprop

PM

M

D

D


Delta-v budget direct transfer, double launch



perigee raise - 10m/s 10m/s

apogee raise - 773m/s 773m/s

split - 148m/s 148m/s




42m/s 218m/s 212m/s

total 252m/s 1304m/s 1272m/s


-


Option 2

• Third table in MA presentation: Delta-v budget direct transfer, single launch

• Basic calculations with basic assumptions


Option 2 •  Mother Spacecraft with biprop propulsion system: 1263 kg (dry mass, including a new biprop system) Generate 788 m/s to itself and the payload

(2 daughter s/c on top + propellant for continued mission)

Then release 2 x daughter s/c and add 567 m/s to the mother s/c

•  Daughter 1 Spacecraft with high thrust bi-prop system: 832 kg (dry mass, including a new biprop system) 535 m/s (Biprop since requires high thrust and considerable ΔV)

•  Daughter 2 Spacecraft with high thrust bi-prop system : 832 kg (dry mass, including a new biprop system) 503 m/s (Biprop since requires high thrust and considerable ΔV)

(assumed same propellant load as daughter1)

M

D

D


Delta-v budget direct transfer, single launch



perigee raise 10m/s 10m/s 10m/s

apogee raise 773m/s 773m/s 773m/s

split 167m/s 167m/s 167m/s




226m/s 218m/s 212m/s

total 1355m/s 1304m/s 1272m/s


Option 2 Mother s/c •  1132 kg + (1.2 x 109) kg = 1263 kg •  Total propellant load 1322 kg •  Wet mass: 2587 kg •  Propulsion system 109 kg Daughter s/c •  759 kg + (1.2 x 61) kg = 832 kg •  Total propellant load 166 kg •  Wet mass: 998 kg •  Propulsion system 61 kg

Stack of wet masses: •  2587 kg + 998 kg +998 kg = 4583 kg

M

D

D


Note:

Based on LISA Pathfinder Propulsion module (with Eurostar 2000 derived tanks)

Resized tanks

2 tanks for daughter S/C

4 tanks for the mother S/C


Daughter S/C Option 2 Element 1 -


new unit1 Pressurant tank 1 7.8 To be developed 5 8.22 Pressurant 1 1.6 To be developed 5 1.73 MMH tank 1 9.4 To be developed 20 11.34 MON tank 1 9.4 To be developed 20 11.35 Propellant residuals 1 0.0 To be developed 0 0.06 Main engines 1 4.3 To be developed 5 4.57 RCS thrusters 8 0.7 To be developed 5 5.58 Gas filter 1 0.2 To be developed 5 0.29 Pressure regulator (Dual) 1 1.1 To be developed 5 1.210 Pyro valves (liquid) 4 0.3 To be developed 20 1.411 Pyro valves (gas) 6 0.1 To be developed 20 0.712 Latch valves 1 0.4 To be developed 20 0.513 Non return valves 4 0.1 To be developed 20 0.514 Fill an drain / vent valves 10 0.1 To be developed 20 0.815 Propellant filter 2 0.2 To be developed 20 0.516 Pressure transducer 4 0.2 To be developed 20 1.017 Pipework 1 5.0 To be developed 20 6.018 Brackets and mountings 1 5.0 To be developed 20 6.0-

18 53.5 14.3 61.2

Unit Quantity Maturity LevelMASS [kg]

SUBSYSTEM TOTAL

Mass per quantity excl.

margin

Click on button below to insert new unit

MarginPart of custom subsystem



Mother S/C Option 2 Element 2 -


new unit1 Pressurant tank 1 7.8 To be developed 5 8.22 Pressurant 1 1.6 To be developed 5 1.73 MMH tank 2 14.6 To be developed 20 35.14 MON tank 2 14.6 To be developed 20 35.15 Propellant residuals 1 0.0 To be developed 0 0.06 Main engines 1 4.3 To be developed 5 4.57 RCS thrusters 8 0.7 To be developed 5 5.58 Gas filter 1 0.2 To be developed 5 0.29 Pressure regulator (Dual) 1 1.1 To be developed 5 1.210 Pyro valves (liquid) 4 0.3 To be developed 20 1.411 Pyro valves (gas) 6 0.1 To be developed 20 0.712 Latch valves 1 0.4 To be developed 20 0.513 Non return valves 4 0.1 To be developed 20 0.514 Fill an drain / vent valves 10 0.1 To be developed 20 0.815 Propellant filter 2 0.2 To be developed 20 0.516 Pressure transducer 4 0.2 To be developed 20 1.017 Pipework 1 5.0 To be developed 20 6.018 Brackets and mountings 1 5.0 To be developed 20 6.0-

18 93.1 16.7 108.7SUBSYSTEM TOTAL Click on button below to insert new unit


Unit Part of custom subsystem

Quantity Mass per quantity excl.

margin

Maturity Level MarginMASS [kg]


Daughter monoprop vs biprop Option 2

•  Biprop Isp = 321 s 166 kg propellant

•  Monoprop Isp = 224 s 247 kg propellant ∆ = 81 kg (in favour of biprop) But this requires larger and heavier tanks, while the savuing on the more simple propulsion system (not even considering the heavier tanks for hydrazine) would be about 20 kg

Biprop seems to be the better choice all systems are equal (except for number and length of tanks)


Documents

Internal Final Presentation …sgo.caltech.edu/lib/exe/fetch.php?media=07_eulisa_chemical...EuLISA – Assessment Study Chemical Propulsion - 2 Option 1