Cold-gas Propulsion for Small Satellite Attitude Control, Station - PowerPoint PPT Presentation

Cold-gas Propulsion for Small Satellite Attitude Control, Station Keeping, and Deorbit. John Furumo*, Nathan Walsh, Evan Greer, Daniel Wukelic, Dr. A. Zachary Trimble, Dr. Trevor Sorensen. 1

Agenda ▶ Small Satellite Background Information ▶ Project Objectives ▶ Cold-Gas System Analysis ▶ Satellite Dynamics ▶ Prototype ▶ Test Results ▶ Conclusion ▶ Future Work and Improvements 2

Functional Requirements ▶ Small Satellite maneuvers ◦ Attitude Control, De-orbit, Orbit Maintenance ▶ 1 year operational lifetime ▶ < 25% total payload mass/volume ▶ Space-rated system ▶ HSFL’s HiakaSat 3

Delta-V Budget 4 Supplemental Slide 48

Propulsion System Trade Study Category Cold Gas Electric Mono Biprop Size 1.250 2.321 2.488 1.850 Performance 0.003 1.000 0.240 1.300 Feasibility 5.000 2.525 2.150 0.615 Total 6.253 5.846 4.878 3.765 5

Why We Chose Cold Gas ▶ Simplest satellite propulsion system ▶ Cheap to build (~$5k budget) ▶ Components and propellant gases readily available ▶ UH facilities are sufficient for fabrication and testing ▶ Propellants are safe to handle and test 6

Cold-Gas System Performance ▶ Propellant Type ◦ Specific Heat Capacity Ratio ◦ Molar mass ◦ Limited by availability, price ▶ Propellant Storage ◦ Volume ⚫ Limited by satellite volume ◦ Pressure ⚫ Limited by pressure vessel ◦ Temperature ⚫ Limited by spacecraft thermal control 7

Cold-Gas Propellant Options Assumptions: Storage Volume = 10 Liters Storage Pressure = 4500 psi (~31MPa) Storage Temp = 0 ° C Cold Gas Propellant N2 CO2 NH3 N2O H2 He Xe Specific Impulse, theoretical, 76.8 67.3 108.3 66.2 285.5 174.7 30.0 metric (s) Propellant Mass (kg) 3.83 6.01 2.32 6.01 0.27 0.55 17.95 Delta-V (m/s) 57.66 79.42 49.37 78.10 15.32 18.74 105.56 8 Supplemental Slide 47

System Layout 9

From Delta-V to Thrust ▶ Trade-off between thrust and time ▶ Set amount of Δ V required for orbit maintenance, deorbit ▶ Variable amount of Δ V for attitude control 10

System Physics De Laval Nozzle Diagram [1] 11

Thruster Design Variables ▶ 12

Thruster Force/Pressure Relation 13

Preliminary Thrust Analysis Assumptions: Nozzle Throat Diameter = 1/16” Nozzle Exit Velocity = 660 m/s Propellant = CO 2 Propellant mass = 6.01 kg Thrust (N) 0.1 1 10 100 Propellant Mass Flow Rate (kg/s) 0.00015 0.00152 0.01515 0.15152 Thruster Pressure (psi) 3.77 37.67 376.73 3767.25 Total Burn Time (s) 11 hours 66.2 min 6.62 min 40 s 14 Supplemental Slide 47

Single Axis Maneuver [1] t m θ m I v n F L 2.08 kg*m 2 7.05 s 180° 2 1 N 0.2627 m (Enough Δ V for 563 maneuvers) 15

Future Analysis Required ▶ Non-ACS thrust vs. time ◦ Orbit Maintenance ◦ Deorbit ◦ Different thruster pressures ▶ More accurate way to characterize Δ V requirement for attitude control ▶ Consult faculty for supersonic flow considerations, nozzle geometry ▶ Control scheme design ▶ Estimation of end-of-life performance 16

Computational Fluid Dynamics Simulations 17

Nozzle Simulation -Simple turbulent flow model through a converging-diverging geometry -Input boundary condition of 10 m/s -Throat velocity increases to approximately 100 m/s 18

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Validation: ▶ Using tabulated data ◦ T 1 =293.15K, P 1 =1 atm=101.3 kPa, V 1 = 10 m/s ◦ A 1 =0.001257 m 2 , A 2 = 0.0001398 m 2 ◦ a 1 = 269.37 m/s (calculated speed of sound, ϒ =1.31) ◦ M 1 = V 1 /a 1 =0.0307 ◦ From tables relating M to A/A * : ⚫ A 1 /A * ≈ 15, A 1 /A 2 =0.1112, and A 2 /A * =1.668 ⚫ Using A 2 /A * , M 2 ≈ 0.375 ⚫ V 2 ≈ 0.375(269.37) = 101 m/s 20

Second Simulation ▶ Change in geometry ▶ Decrease in throat area ▶ Input condition of 2 m/s 21

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Future Simulation Work ▶ We wish to simulate the flow under an operating pressure of 37.7 psi ▶ The turbulent flow physical model within Comsol only supports flow, Ma < 0.3 ▶ We will use the high mach number flow model 23

▶ Errors have been encountered that suggest the problem is not fully defined ▶ Attempts to look at the set up of other example models have failed to solve the problem ▶ We will consult Comsol support to resolve issues of this model 24

Satellite Dynamics 25

Moments 26

Couple Moment 27

Pairs of Thrusters Rotation Type Thrusters Used X-Negative 1,5 X-Positive 3,7 1,3 Y-Negative 2,4 1,2,3,4 5,7 Y-Positive 6,8 5,6,7,8 Z-Negative 4,6 Z-Positive 2,8 Maneuvers: - Attitude Control (ACS) - De-Orbit - Orbit Maintenance 28

Deliverables 29

Deliverables Prototype Flight Model Will Be Built For Testing Concept Only 30

Prototype ▶ For 1-axis control testing ▶ 4 Thrusters to control spin in both directions ▶ Nozzle designed for ambient atmospheric application ▶ All parts are COTS other than nozzles ▶ Manually controlled components 31

Flight Model ▶ Full Features ▶ Space worthy components ▶ Differences from prototype ◦ 8 nozzles (3-axis control) ◦ More custom parts ◦ Electronically controlled components ◦ Nozzle designed for use in vacuum 32

Manufacturing Approach 33

Pressure Transducer Model: PX300 Series [2] Range: 0 to 1000 Psi Accuracy: 0.25% Full Scale Excitation: 10 Vdc (5 to 15 Vdc Limits) Output: 3mV/V ratiometric 30mV ±1mV @ 10V Model: G17M0142F21000# [3] Range: 0 to 1000 Psi Accuracy: +/-0.5% Full Scale Output: 4 to 20 mA at 12 to 30VDC Power Required: 9 to 36VDC Max. Pressure: 2000 psi 34

Tank Ninja Carbon Fiber Tank [4] Size: 90 cubic inch Max Tank Pressure: 4500 psi Output Pressure: 800~850 psi Cylinder Weight: 3.3 pounds Luxfer D Air Tank [5] Service Pressure 2015 psi Oxygen Capacity 14.7 cu ft Outside Diameter 4.4” Empty Weight 5.0 lbs Internal Volume 172 cu in Thread Size 0.750-16 UNF-2B 35 http://www.paintballrevolution.com/pureenergy70ci4500psiultrapaintballtank-1-1-1-1-1-1-1-1.aspx http://www.ultimatepaintball.com/p-9515-ninja-carbon-fiber-n2-paintball-tank-90ci4500psi-grey.aspx?CAWELAID=1513094504&catargetid=1391382590&ca gpspn=pla&gclid=CNaozPKA_7MCFSFyQgodNEsA1Q (pic used in CDR)

Pressure Regulator Mega Regulator Dual Stage [6] · Dual Stage Regulator · Adjustable from 0-950 PSI · Tank Thread 5/8(.625)inch -18 UNF PR-57 Series Pressure Regulator [7] · 316L stainless steel construction · 20µ filter · Inlet pressure maximum 10,000 psi · Outlet pressure ranges are 0–10,00 psi · Operating temperatures: −40° F to +150° F 36

Carbon Dioxide Phase Diagram [8] 37

Cold Gas Thruster Valve Solenoid Actuated Thruster Valve (Single Seat) [9] Operating Pressure: 500 psig Response time: 15 ms maximum Power Consumption: 27 Watts Engine Thrust Rating: 40 N Weight: 0.23 kg Type: Stainless Steel Model No. SVS03 [10] Operating Pressure: 1750 psi Response Time: < 10 ms Operating Voltage: 28 ± 4 VDC Engine Thrust: 5 N Weight: 0.110 Kg Type: Stainless Steel 38

Thruster Nozzles ▶ Completely custom ▶ Throat diameter: 1/16” ▶ Exit diameter: 1” ▶ Area expansion ratio: ~257 ▶ Converging-diverging profile TBD 39

Project Management 40

Projected Cost and Budget 41

Project Schedule UPDATE 42

Mahalo! 43

References [1] Brown, Charles D. “Fig. 2.1 Rocket Nozzle”, Spacecraft Propulsion, 1 st Edition. AIAA Press, 1996. [2]http://www.omega.com/pptst/px300.html [3]http://www.drillspot.com/products/1330697/Pressure_Transducer_G17M0142F21000_Pressure_Transducer ?s=1&catargetid=1623454804&gclid=CJv5ydui_bMCFQhyQgod73oA1A [4] http://www.ultimatepaintball.com/p-9515-ninja-carbon-fiber-n2-paintball-tank-90ci4500psi-grey.aspx?CA WELAID=1513094504&catargetid=1391382590&cagpspn=pla&gclid=CNaozPKA_7MCFSFyQgodNEsA1Q [5]http://lakecourt.com/pc_product_detail.asp?key=4A2113A89C1541758F7D665427ACFE6E [6] http://www.sakworldpaintball.com/meredustadta.html [7] http://www.circle-seal.com/products/pressure_regulators/pr57/index.html [8] University of Toronto, “Physics: The Properties of Permafrost” Mentorship Program. Available online. Link: http://www.physics.utoronto.ca/~exploration/UofT-mentorship/Physics_CO2.html [9] http://www.moog.com/products/propulsion-controls/spacecraft/components/thruster-valves/solenoid-act uated-thruster-valve-single-seat-/ [10] http://www.ampacispcheltenham.eu/pages/prsolenoid8.htm 44

Supplemental Slide - Old Delta-V Budget 45

Supplemental Slide - Propulsion System Size Estimates 46

Supplemental Slide - Propulsion System Performance Cold Gas Electronic Mono Biprop Solid Performance low med high high very high Thrust .001-3.5N 8-2000mN .19-3780N .009-110kN 25-81kN Specific 45-73s 500-3000s 200-235s 274-466s 290-304s Impulse 47

Supplemental Slide - Cold Gas Propellants 48

Supplemental Slide - New Delta-V Budget 49

Supplemental Slide – System Delta-V I total (N·s): Total propellant mass consumed times the average specific impulse I sp (s): Specific impulse is the thrust generated per unit mass flow rate of propellant 50