Spreadsheet: 09253d18-87c9-4a5a-8b17-c0bda9279e85
Sheet: Propulsion Subsystem Sizing

Propulsion Subsystem Sizing |  |  |  |  | Mission Duration |  |  | Constants
 |  |  |  |  | Years | 5 |  | Earth Radius (m) | 6378100
 | Bus Dimensions |  |  |  | Days |  |  | mu, Earth (m^3/s^2) | 398600000000000
 | [NAME] (m) | 2.16 |  |  | Hours |  |  | Margin (15%) | 0.15
 | Height (m) | 7.2 |  |  | Minutes |  |  | g0 (m/s/s) | 9.81
 | Mass Wet (kg) | 750 |  |  | Seconds |  |  | Thrust Required (N) | 15
 | [NAME] (kg) | 650 |  |  |  |  |  | Thruster Expansion Ratio | 25
 |  |  |  |  |  |  |  | Thruster Regulated Pressure (Pa) | 1723700
 |  |  | Margin (15%)
 | Ix ([NAME])
 | Iy ([NAME])
 | Iz ([NAME])
 | Titanium Tank Properties | Density (kg/m^3) | 4430
 | 6AL-4V | in. | m.
 | Thickness | 0.04
 |  | ksi | MPa
 | Modulus of Elasticity (E) | 15200 | 104800.34
 | Diameter | 48 | 1.2192
 | Tank Volume | [NAME] | m^3
 | Material Volume | [NAME] | m^3
 | Mechanical Properties | ksi (avg.) | MPa (avg.)
 | Ultimate Bearing Strength | 250 | 1425
 | Compressive Yield Strength | 125 | 860
 | Ultimate Shear Strength | 85 | 585
 | Density | lb/in^3 | [NAME]
 |  | 0.16 | 4428.78475
 | Tank Mass | lbs | [NAME]
 | Hoop stress, [NAME] pressure | [NAME] | Mpa
 | Sphere | 250 | 1.7237
Distrubance Torques
Orbit Types
Case 1 | Alt. (m) | 1000000
Circular LEO 1000 km alt., 0 deg.
Case 2
Circular LEO 1000 km alt., 28-62 deg.
 |  | Nominal | Worst-Case
 | Gravity Gradient, [NAME] (N-m) |  |  | Z-axis deviation (deg) | 1 | 45
 |  | Nominal | Worst-Case
 | Solar Radiation, Tsp (N-m) |  |  | Solar constant (W/m^2) | 1367
 |  |  |  | Speed of light (m/s) | 300000000
 |  |  |  | csp-cp offset (m) | 0.3
 |  |  |  | Incidence angle (deg.) | 25 | 0
 |  |  |  | Reflectivity | 0.6 | 1
 |  |  |  | Surface Area (m^2)
 |  | Worst-Case
 | Magnetic Field, Tm (N-m) |  |  | Magnetic [NAME] ([NAME]) | 5
 |  |  |  | Worst-case Polar Magnetic Field (tesla*m^3) | 4.5e-05
 |  | Worst-Case
 | Aerodynamics, T (N-m) |  |  | cm-cp offset (m) | 0.3
 |  |  |  | Orbit Velocity (m/s)
 |  |  |  | Density Approximation (kg/m^2) | 1e-13
 |  |  |  | Cd | 2
 |  | Nominal | Worst-Case
 | Total Torque, Case 1 (N-m)
 | Total Torque, Case 2 (N-m)
Orbit Types
Case 3 | Alt. (m) | 35786000
[NAME] alt., 0 deg.
Case 4
Geosynchronous 35786 km alt., [NAME].
 |  | Nominal | Worst-Case
 | Gravity Gradient, [NAME] (N-m) |  |  | Z-axis deviation (deg) | 1 | 45
 |  | Nominal | Worst-Case
 | Solar Radiation, Tsp (N-m) |  |  | Solar constant (W/m^2) | 1367
 |  |  |  | Speed of light (m/s) | 300000000
 |  |  |  | cm-cp offset (m) | 0.3
 |  |  |  | Incidence angle (deg.) | 25 | 0
 |  |  |  | Reflectivity | 0.6 | 1
 |  |  |  | Surface Area (m^2)
 |  | Worst-Case
 | Magnetic Field, Tm (N-m) |  |  | Magnetic [NAME] ([NAME]) | 5
 |  |  |  | Worst-case Polar Magnetic Field (tesla*m^3) | 4.5e-05
 |  | Worst-Case
 | Aerodynamics, T (N-m) |  |  | cm-cp offset (m) | 0.3
 |  |  |  | Orbit Velocity (m/s)
 |  |  |  | Density Approximation (kg/m^2) | 5.12e-19
 |  |  |  | Cd | 2
 |  | Nominal | Worst-Case
 | Total Torque, Case 3 (N-m)
 | Total Torque, Case 4 (N-m)
Sizing Reaction Wheels, Momentum Wheels and Magnetic Torquers
 | Reaction wheel torque | Disturbance Torques Summary | Nominal |  | Worst-Case
 |  |  | Ideal | Margin (25%) | Ideal | Margin (25%)
 |  | Total Torque, Case 1 (N-m)
 |  | Total Torque, Case 2 (N-m)
 |  | Total Torque, Case 3 (N-m)
 |  | Total Torque, Case 4 (N-m)
 | Slew Torque for Reaction Wheels | Worst-Case Slew Manuever (deg.) | 30
 |  | Maneuver Time (min.) | 5
 |  | Torque (N-m)
 | Momentum Storage in Reaction Wheel |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | Orbital Period (s)
 |  | Momentum Storage, Reaction Wheel (N-m-s)
 |  | Reaction Wheel Storage, 10x margin (N-m-s)
 | Momentum Storage in Momentum Wheels |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | [NAME] (deg.) | 1 | 1 | 1 | 1
 |  | Momentum Storage, Momentum Wheels (N-m-s)
 | Momentum Storage in Spinner |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | Bus Spin Rate (rad/sec)
 |  | Bus Spin Rate (rpm)
 | Torque from Magnetic Torquers |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | [NAME] (A-m^2)
Preliminary [NAME]
 | Force For External Disturbances (N) |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | Moment Arm (m)
 |  | Force (N)
 | Force For Slewing Maneuver (N) |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | Worst-Case Slew Angle (deg.) | 90 | 90 | 90 | 90
 |  | Time For Maneuver (sec) | 450 | 450 | 450 | 450
 |  | Rate (deg./sec)
Worst-Case Forces Used for ADCS Propellant Mass |  | Accelration (rad/sec^2)
 |  | Force (N)
 | Force For Slewing A Momentum Bias Vehicle (N) |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | Thruster Duty Cycle (% of Spin Period) | 0.1 | 0.1 | 0.1 | 0.1
 |  | Worst-Case Slew Angle (deg.) | 90 | 90 | 90 | 90
 |  | Angular Momentum (N-m-s)
 |  | Time For Slew Maneuver (min.) | 10 | 10 | 10 | 10
 |  | Average Thruster Force (N)
 | Thruster Pulse Life |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
Assume |  | Number of Freedom Axis | 3 | 3 | 3 | 3
Large maneuver of 90 deg done in 2 axes each week |  | Numbers of Reaction Wheels | 4 | 4 | 4 | 4
3 sec acceleration and 3 sec deceleration |  | Total Pulses
 | Force For Momentum Dumping |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
 |  | Burn Pulse Time (sec) | 5 | 5 | 5 | 5
 |  | Force (N)
 | ADCS Propellant Mass |  | Cases 1 and 2 Nominal | Cases 1 and 2 Worst-Case | Cases 3 and 4 Nominal | Case 3 and 4 Worst-Case
Assume |  | Large Maneuver Pulse #
3 sec on time for large maneuvers |  | Momentum Dumping Pulse # | 7300 | 7300 | 7300 | 7300
1 sec on time for momentum dumps |  | Large Pulse Time On (sec.) | 3 | 3 | 3 | 3
 |  | Momentum Dump Time on (sec.) | 1 | 1 | 1 | 1
 |  | Delta time (sec.)
 |  | Total Impulse (N-s)
 |  | [NAME] | Type | Isp (s)
 |  | Cold Gas | Air
 |  |  | Argon (Ar)
 |  |  | C02
 |  |  | He
 |  |  | H2
 |  |  | N2
 |  |  | O2
 |  |  | Butane
 |  |  | Propane
 |  | Low Power Ion | 0.08 - 0.5 kW per thruster (low end) | 847
 |  |  | 0.08 - 0.5 kW per thruster (high end) | 2585
 |  | [NAME] | Type | Isp (s)
 |  | Monoprop | GREEN LMP-101X
 |  |  | GREEN LMP-102
 |  |  | GREEN LMP-103X
 |  |  | GREEN ADN/Methanol, 26% water
 |  |  | GREEN HAN/Methanol, 26% water
 |  |  | GREEN HAN/Glycine, 26% water
 |  |  | [NAME], 60% Amm. Diss.
 |  |  |  |  | ADCS Propellant Mass (kg) | Total Propellant Mass Before Margin (kg) | Margin | Total Propellant Mass After Margin (kg)
 |  | Cases 1 and 2 Nominal | Cold Gas | Air |  |  | 0.05
 |  |  |  | Argon (Ar) |  |  | 0.05
 |  |  |  | C02 |  |  | 0.05
 |  |  |  | He |  |  | 0.05
 |  |  |  | H2 |  |  | 0.05
 |  |  |  | N2 |  |  | 0.05
 |  |  |  | O2 |  |  | 0.05
 |  |  |  | Butane |  |  | 0.05
 |  |  |  | Propane |  |  | 0.05
 |  |  | Low Power Ion | 0.08 - 0.5 kW per thruster (low end) |  |  | 0.05
 |  |  |  | 0.08 - 0.5 kW per thruster (high end) |  |  | 0.05
 |  |  | Monoprop | GREEN LMP-101X |  |  | 0.05
 |  |  |  | GREEN LMP-102 |  |  | 0.05
 |  |  |  | GREEN LMP-103X |  |  | 0.05
 |  |  |  | GREEN ADN/Methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/Methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/Glycine, 26% water |  |  | 0.05
 |  |  |  | [NAME], 60% Amm. Diss. |  |  | 0.05
 |  | Case 1 and 2 Worst-Case | Cold Gas | Air |  |  | 0.05
 |  |  |  | Argon (Ar) |  |  | 0.05
 |  |  |  | C02 |  |  | 0.05
 |  |  |  | He |  |  | 0.05
 |  |  |  | H2 |  |  | 0.05
 |  |  |  | N2 |  |  | 0.05
 |  |  |  | O2 |  |  | 0.05
 |  |  |  | Butane |  |  | 0.05
 |  |  |  | Propane |  |  | 0.05
 |  |  | Low Power Ion | 0.08 - 0.5 kW per thruster (low end) |  |  | 0.05
 |  |  |  | 0.08 - 0.5 kW per thruster (high end) |  |  | 0.05
 |  |  | Monoprop | GREEN LMP-101X |  |  | 0.05
 |  |  |  | GREEN LMP-102 |  |  | 0.05
 |  |  |  | GREEN LMP-103X |  |  | 0.05
 |  |  |  | GREEN ADN/Methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/Methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/Glycine, 26% water |  |  | 0.05
 |  |  |  | [NAME], 60% Amm. Diss. |  |  | 0.05
 |  | Case 3 and 4 Nominal | Cold Gas | Air |  |  | 0.05
 |  |  |  | Argon (Ar) |  |  | 0.05
 |  |  |  | C02 |  |  | 0.05
 |  |  |  | He |  |  | 0.05
 |  |  |  | H2 |  |  | 0.05
 |  |  |  | N2 |  |  | 0.05
 |  |  |  | O2 |  |  | 0.05
 |  |  |  | Butane |  |  | 0.05
 |  |  |  | Propane |  |  | 0.05
 |  |  | Low Power Ion | 0.08 - 0.5 kW per thruster (low end) |  |  | 0.05
 |  |  |  | 0.08 - 0.5 kW per thruster (high end) |  |  | 0.05
 |  |  | Monoprop | GREEN LMP-101X |  |  | 0.05
 |  |  |  | GREEN LMP-102 |  |  | 0.05
 |  |  |  | GREEN LMP-103X |  |  | 0.05
 |  |  |  | GREEN ADN/Methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/Glycine, 26% water |  |  | 0.05
 |  |  |  | [NAME], 60% Amm. Diss. |  |  | 0.05
 |  | Case 3 and 4 Worst-Case | Cold Gas | Air |  |  | 0.05
 |  |  |  | Argon (Ar) |  |  | 0.05
 |  |  |  | C02 |  |  | 0.05
 |  |  |  | He |  |  | 0.05
 |  |  |  | H2 |  |  | 0.05
 |  |  |  | N2 |  |  | 0.05
 |  |  |  | O2 |  |  | 0.05
 |  |  |  | Butane |  |  | 0.05
 |  |  |  | Propane |  |  | 0.05
 |  |  | Low Power Ion | 0.08 - 0.5 kW per thruster (low end) |  |  | 0.05
 |  |  |  | 0.08 - 0.5 kW per thruster (high end) |  |  | 0.05
 |  |  | Monoprop | GREEN LMP-101X |  |  | 0.05
 |  |  |  | GREEN LMP-102 |  |  | 0.05
 |  |  |  | GREEN LMP-103X |  |  | 0.05
 |  |  |  | GREEN ADN/Methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/methanol, 26% water |  |  | 0.05
 |  |  |  | GREEN HAN/Glycine, 26% water |  |  | 0.05
 |  |  |  | [NAME], 60% Amm. Diss. |  |  | 0.05
Cold Gas Thruster Design |  | Nominal and Worst Case Mass Flow Rates For Both Orbit Types (kg/s) | [NAME] (m^2) | [NAME] (cm) | Thruster Exit Area (m^2) | Thruster Exit Diameter (cm)
Cold Gas | Air
 | Argon (Ar)
 | C02
 | He
 | H2
 | N2
 | O2
 | Butane
 | Propane
Tank Volume Calculations | Temp. (K) | 298.15
 |  | Case 1 and 2 Nominal | Case 1 and 2 Worst-Case | Case 3 and 4 Nominal | Case 3 and 4 Worst-Case
Requirements Defined |  | Calculated Tank Volume (m^3) | Calculated Tank Volume (m^3) | Calculated Tank Volume (m^3) | Calculated Tank Volume (m^3) |  | [NAME]
1. 15 N thrust total in a vacuum | Air |  |  |  |  |  | Physical Tank Volume, 1 tank (m^3)
2. 8380 seconds of thrust | Argon (Ar) |  |  |  |  |  | 2 Tank Volume (m^3)
3. Use a low reactivity gas | C02 |  |  |  |  |  | 4 Tank Volume (m^3)
4. Intermittent system operation as needed | He
5. Gas storage at 298.15 K | H2
Assume | N2
1. No losses in feed lines, valves, or regulators | O2
2. No pressure or mass flow losses in the nozzle | Butane
3. Isentropic flow from the regulator to the nozzle exit | Propane
4. intermittent operation allowing the gas in the storage tank and the feed lines to be isothermal at a temperature of 298.15 K | 0.08 - 0.5 kW per thruster (low end)
 | 0.08 - 0.5 kW per thruster (high end)
 | GREEN LMP-101X
 | GREEN LMP-102
 | GREEN LMP-103X
 | GREEN ADN/Methanol, 26% water
 | GREEN HAN/Methanol, 26% water
 | GREEN HAN/Glycine, 26% water
 | [NAME], 60% Amm. Diss.