More Attitude Control Thruster Options
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AAE450 Spring 2009 More Attitude Control Thruster Options Brittany Waletzko Translunar/OTV Phase Week 7 Brittany Waletzko - ATT
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More Attitude Control Thruster Options. Brittany Waletzko Translunar /OTV Phase Week 7. The Scenario. Need thrusters to despin / desaturate reaction wheels during TLI Must be capable of impulsive Δ V ~50 m/s - PowerPoint PPT Presentation
Transcript of More Attitude Control Thruster Options
AAE450 Spring 2009
More Attitude Control Thruster Options
Brittany WaletzkoTranslunar/OTV Phase
Week 7
Brittany Waletzko - ATT
AAE450 Spring 2009
The Scenario Need thrusters to despin/desaturate
reaction wheels during TLI Must be capable of impulsive ΔV ~50 m/s Already using Electric Propulsion for main
engine utilize power for attitude control?
Brittany Waletzko - ATT<1>
AAE450 Spring 2009
Bottom-Line Figures
Brittany Waletzko - ATT<2>
(hydrazine monopropellant system uses <1W)Bottom line: Neither of these options is likely to be the best option based on cost,
power consumption, and complexityFuture Work: Solidifying supporting hardware mass/power/cost figures, OTV integration work
Electrothermal Hydrazine Resistojet Arcjet
Vacuum Thrust (N) 0.5-1 0.1-0.23
Input Power (W) 500/thruster 300/thruster
System Mass, 4 thrusters + PPU (kg) 6.5 1.22Max Exhaust Velocity (km/s) 10 4 to 5
Max Isp (s) 300 500Life Span (hrs) ~380 1000-1500
Cost ~ $150,000 for either
AAE450 Spring 2009
Questions?
Brittany Waletzko - ATT<3>
AAE450 Spring 2009 Brittany Waletzko - ATT<4>
Thruster Locations and Thrust Direction Vectors
Thruster placement planned with assistance from Brian Erson
AAE450 Spring 2009
How They Work
Brittany Waletzko - ATT
Source: TU Delft website
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AAE450 Spring 2009
Further Comments
Brittany Waletzko - ATT
Arcjets
Electrode erosion in 1000-1500hrs (62 days)
90% efficient --> 267 W in means 30W heat dissipated
Needs PPU 0.3 kW, 0.5kg
Constrictor diameter 0.25mm, length .13mm
Cathode diameter 1.6mm
Thruster mass 0.18 kg
Resistojets
35-40% better performance than no heatingHeating configuration is crucial--indirect heating of prop has longer lifeSteady or pulsedINTELSAT used 0.55 kW per thruster N2H4, stationkeepingIridium 0.5 kW per thruster N2H4, orbit adjustment
Mass ~ 0.36 kg
~500 W for heating systems
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AAE450 Spring 2009
Updated System Estimates
Brittany Waletzko - ATT
8 thrusters may be too redundant; 4 already allows for the loss of one thruster, 8 makes the entire system redundant reliability analysis needed
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AAE450 Spring 2009
Primary References Monopropellant Hydrazine Thrusters. Astrium Space Propulsion. 21 Jan 2009.<http://cs.astrium.eads.net/sp/SpacecraftPropulsion/MonopropellantThrusters.html> Rocket Research Corporation. "Final Report for Monopropellant Hydrazine
Thruster System," 1965. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670030394_1967030394.pdf
Eric Wernimont, Ph.D. General Kinetics, Inc.: Huntington Beach, CA. Email Correspondence 7 Feb - 10 Feb 2009.
<http://www.marotta.com/DataSheets/MV100series.htm> <http://www.circlesealcontrols.com/products/atkomatic_valves/pdf/
cscatkoc_2007-10_lo.pdf> “Electrothermal Hydrazine Data” and many other links
<http://www.lr.tudelft.nl/live/pagina.jsp?id=6cf1d7c6-dd9a-432b-b40e-02f4f8ed0d0d&lang=en>
Sellers, “Investigation Into Cost-Effective Propulsion System Options for Small Satellites.” Journal of Reducing Space Mission Cost, 1998.
Pinero and Bowers. “Power Electronics for a Miniaturized Arcjet.” 32nd Joint Propulsion Conference and Exhibit,” 1996.
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