CDR Titan EDD Fall Semester 12/02/2008 Andrew Welsh Jon Anderson Nick Delucca Steve Hu Travis Noffke Pawel Swica Andrew Welsh 1 Team Member Andrew Welsh Team Lead Hours Worked: 108 Andrew Welsh 2 Agenda Titan EDD CDR Agenda: •Introduction and Overview – Andrew Welsh • Entry Position and Entry Capsule – Pawel Swica • Entry Simulation and Atmospheric Profile – Nick Delucca • Parachute and Parachute Deployment – Travis Noffke • Airship and Airship Deployment – Jon Anderson • Helicopter and Helicopter Deployment – Steve Hu • FMEA – Andrew Welsh Andrew Welsh 3 Overview Purpose: • Design a system to insert an aerial vehicle into Titan’s atmosphere capable of exploring the ethane lake on Titan’s south pole. Ontario Lacus (Credit: Right image - NASA/JPL/University of Arizona Left image - NASA/JPL/Space Science Institute) Andrew Welsh 4 Overview Mission Description: • 2018 tentative launch date • Aerial vehicle four year operational lifetime • Aerial vehicle: Helicopter, Airship, Fixed Wing • Capable of exploring Ontario Lacus Andrew Welsh 5 Requirements 1. Design an Entry, Descent, and Deployment (EDD) process and select an aerial vehicle based of work done elsewhere. 2. EDD system capable of delivering the aerial vehicle on or near the surface of Titan. • Heating Constraints • Deceleration Constraints 3. Aerial vehicle must at a minimum be able to explore Ontario Lacus. 4. Successful aerial vehicle deployment in a configuration capable of beginning its exploration mission. Andrew Welsh 6 Requirements Major Tasks (Given): • Review previous work done in this area • Top level trade study for EDD configuration • Develop or modify an entry and descent phase simulation • Design a baseline entry and descent phase • Identify the aerial exploration vehicle • Design aerial vehicle separation method • Integrate all systems into a package that will take aerial vehicle from insertion to employment • Formula derivations Andrew Welsh 7 Requirements Major Tasks (Added): • Detailed aerial vehicle selection • EDD animation • Bad weather simulation Andrew Welsh 8 Approach Team Lead: Andrew Welsh Integration Team: Travis Noffke, Pawel Swica, Steve Hu Entry Team: Nick Delucca, Pawel Swica Descent Team: Travis Noffke, Andrew Welsh Andrew Welsh Dep. Team: Jon Anderson, Steve Hu 9 Approach Research Aerial Vehicle Selection Descent Method Selection Previous Research Entry Method Selection Our Research and Calculations Final Product Andrew Welsh 10 Program Plan Gantt Chart Andrew Welsh 11 Program Plan Task list with responsible engineers, status, hours worked, total hours worked Andrew Welsh 12 Design Walkthrough Andrew Welsh 13 References 1. 2. http://www.sciencedaily.com/releases/2008/07/0807301 40726.htm https://www.aem.umn.edu/courses/aem4331/fall2008/Ti tanExplorer.htm Andrew Welsh 14 Team Member Pawel Swica Entry/Integration Hours Worked: 101 Pawel Swica 15 1 Initial Orbit Calculation •First thing done was orbit calculation to reach Titan •The final entry speed was 3.6 km/s •However, the orbity relied on a large change in velocity at earth orbit •Though entry speed was better, published materials detailed how an ion engine powered by solar cells would make launch less expensive Pawel Swica 16 Relevant Equations Pawel Swica 17 Orbit Diagrams Pawel Swica 18 Orbit Diagrams Pawel Swica 19 Orbit Diagrams Pawel Swica 20 Resulting trade study Pawel Swica 21 Heat Shield • To get an idea of heating, an attempt was made to get an equation that we could put into simulink to get heating during entry • While mostly successful the results were off by some fudge factor • We went to Professor Candler for assistance • 10/14 notes from meeting with Candler – Detailed modeling of entry heating unrealistic given our level of experience – Best approach would be to tweak results of previous publications to fit our conditions (emphasis on Laub paper) Pawel Swica 22 Relevant Equations Pawel Swica 23 Heat Shield Results • Results were taken from Laub paper for mass and material • SRAM material and less radiative heating gave up to 100 kg mass savings from previous study Figure 5. Aeroshell model Figure 4. Entry heating graph Pawel Swica 24 Entry Corridor • • Our gathered materials gave no indication of what the entry corridor was or how it could be determined 10/24 notes from meeting with Candler – No easy way to determine entry corridor – Hunt through references to find entry angle used – Also can plug angles into simulink to see corridor • Found entry corridor information in AAS 06-077 • 50º down at entry interface (1000 km) with 5º margin in either direction • Modeling in simulink roughly agreed with these values Pawel Swica 25 Calculation of Landing Point • Lastly the point where the probe is expected to land needed to be calculated • Outside searches proved fruitless, however using the given initial conditions calculation was possible and successful Pawel Swica 26 Relevant Calculations Pawel Swica 27 Conclusive Results • Ontario Lacus lies at latitude 72º and the downstream distance given by simulink is 1200 km • Based on the final results of the calculations, the probe can land as close as 181 km from Ontario Lacus. This is a very manageable distance for the probe to traverse • However, if the planet is facing the wrong way, this distance could become almost 1800 km, in which case reaching the lake would depend heavily on the durability of the probe • This depends on timing the approach just right, which is beyond the scope of our analysis Pawel Swica 28 Vpython Model • To verify results a Vpython orbit script was modified to match the precise conditions given by the calculations • To ensure accuracy, starting point is about 180 Titan radii out Pawel Swica 29 Vpython Video Pawel Swica 30 Team Member Nick De Lucca Titan Atmosphere Entry Simulation 113 Hours Nick De Lucca 31 Atmospheric Profile • Needed Information – Density – Temperature • Sources – From 50 km to 1000 km data pulled from plots generated by others – Sea level to 50 km data from email correspondence. Nick De Lucca 32 Titan Entry Simulation • Goals: – Determine flight characteristics as a function of time – Analyze heating • Simulation Method: – Newtonian aerodynamics – Attempted heating calculation – Given original version of simulation by Professor Garrard Nick De Lucca 33 Newtonian Aerodynamics • Formulas: GMm Fg R2 1 2 m FD v 2 B FB Vg B m CD A c 20.05 T Nick De Lucca 34 Simulation Methods and Parameters • Polar Coordinate System – Using Velocity and Flight Path angle as reference directions • Atmospheric Modeling – Two exponential profiles for density – Three linear temperature profiles Nick De Lucca 35 Thermodynamic Analysis • Original Plan: Model using Simulink – Too complicated to manage within time allowance and with our current • Current Method – Adapt the results of others – Scale for our ballistic coefficient – Determine location of peak heating by normalizing Nick De Lucca 36 Simulation Scope • Three Total Simulations: – 1000 km to 8 km: entry capsule – 8 km to 5.6 km heat shield with inflating airship • Time variant ballistic coefficient • Buoyancy – 5.6k km and below heat shield with helicopter Nick De Lucca 37 Results • • • • Total time taken: 3947 seconds m Peak deceleration: 86.6 s 2 Maximum heating rate: 146 W Total heat Transferred: 22552 J Nick De Lucca 38 Results Position 1000 900 800 700 Altitude 600 500 400 300 200 100 0 0 200 400 600 Down Range (km) Nick De Lucca 800 1000 1200 39 Results Position 8.5 8 Altitude (km) 7.5 7 6.5 6 5.5 5 1174 1174.05 1174.1 1174.15 1174.2 1174.25 Down Range (km) Nick De Lucca 1174.3 1174.35 1174.4 40 Results 1000 900 800 700 Altitude 600 Position 500 Normalized Heating 400 Normalized Deceleration 300 200 100 0 0 200 400 600 Down Range (km) 800 Nick De Lucca 1000 1200 41 Results Velocity 7 6 Velocity (km/s) 5 4 3 2 1 0 0 200 400 600 800 1000 Time (s) Stephen Hu 1200 1400 1600 1800 2000 42 Results Time Dependencies 1200 1000 Distance (km) 800 Down Range 600 Altitude Normalized Heating 400 Normalized Deceleration 200 0 0 200 400 600 800 1000 Time (s) Nick De Lucca 1200 1400 1600 1800 2000 43 Methods for improvement • Non-Newtonian aerodynamics • CFD for the heat shield Nick De Lucca 44 References • Dynamics and Thermodynamics of Planetary Entry. W.H.T. Loh. Prentice-Hall Space Technology Series. 1963. • Kazeminejad et al. Temperature Variations in Titan's Upper Atmosphere: Impact on Cassini/Huygens. Annales Geophysicae 23. pp1183-1189. 2005 Stephen Hu 45 Titan Entry Descent and Deployment: Descent Phase Parachute Decelerator System for Aeroshell Separation Travis Noffke •Decelerator System Definition •Parachute Characterization and Mechanics •Aeroshell Separation Analysis •System Integration •Hours: 104 11/19/2008 Travis Noffke 46 Primary Goals 1. Provide deceleration force to top of aeroshell 2. Clearance of unnecessary system components 3. Minimize payload descent stability disruption 11/19/2008 Travis Noffke 47 Requirements 1. Deploy decelerator at altitude which allows for airship inflation prior to final separation and deployment 2. 10 meter clearance between top aeroshell and leading payload within 5 seconds 3. Maintain stable descent of each payload component to respective deployment phase 11/19/2008 Travis Noffke 10 meters Payload Containment 48 System Events 1. 2. 3. 4. 5. Aeroshell separation mechanism fires Mortar fires deployment bag Parachute inflates Deceleration on top aeroshell Complete separation V top Payload Containment V payload 11/19/2008 Travis Noffke 49 Design Tasks Geometry Selection Parachute Characterization • Sizing • Opening Forces Conical Ribbon 1.5 m Diameter nom • Loading • Mass Ratio • Ballistic Coefficient • Material Selection • Canopy Design 11/19/2008 Kevlar© 29 Travis Noffke 50 Drag Generation and Time v terminal = 12 m/s c D = 0.50 Altitude = 8 km Atmospheric Density (ρ)= 3.910 kg/m^3 11/19/2008 Travis Noffke 51 Opening Forces 11/19/2008 Travis Noffke 52 Separation Mechanics Example of separation mechanism Commonly used in spacecraft Performance must meet requirements One of several methods Figure 5. Separation Spring Concept 11/19/2008 Travis Noffke 53 Canopy Structure 11/19/2008 Travis Noffke 54 Canopy Material Kevlar© 29 • • • • Highest strength-weight ratio Superior tensile strength Space tested Used in heritage systems 11/19/2008 Travis Noffke 55 Further Studies • Separation System – Nominal functionality test – Drop testing • Parachute Decelerator System – Deployment Test – Drop Test • Stability Analysis – Test body and flow measurements for appropriate Re 11/19/2008 Travis Noffke 56 Additional Information (Backup Slides) Deceleration Method Trade Study Complexity: Cost: Risk: Efficiency: Availability Effectiveness 11/19/2008 Aero-control Rockets Parachutes Surfaces High Low Med High Low High High Low Med Low High High Med High Med High High Med Travis Noffke 57 Additional Information (Backup Slides) Parachute Geometry Study Characterization Reliability: Mass: Average Oscillation Angle Drag Coefficient Range Opening Force Coefficient Performance Comparison Reliability: Mass: Average Oscillation Angle: Drag Coefficient Range: Opening Force Coefficient: 11/19/2008 Conical Ribbon High Less ±3° .5 to .6 1.05 to 1.3 Conical Ribbon + + + + + Travis Noffke Disc-Gap-Band High More ±10 to 15° .52 to .58 1.3 Disc-Gap-Band + + 58 Additional Information (Backup Slides) Parachute Cluster Configuration Trade Study Single Conical Cluster Ribbon Parachute Reliability: High High Difficulty: Med Low Redundancy: High Low Stability High+ HighCost: High Low Mass: High Med Andy Welsh 11/19/2008 Travis Noffke 59 Additional Information (Backup Slides) Parachute Avoidance Trade Study Rocket Assisted Parachute Separation Separation Complexity: High Med Cost: High Low Risk: Med Low Effectiveness: High MedAndy Welsh 11/19/2008 Travis Noffke 60 Additional Information (Backup Slides) Used Derivations: 11/19/2008 Travis Noffke 61 Additional Information (Backup Slides) 11/19/2008 Travis Noffke 62 Team Member Jon Anderson Hours Worked: 118 Jon Anderson 63 Outline Outline: • • • • • • • • Objective • Vehicle selection • Airship Design Design constraints Assumptions General design Performance Deployment Enabling technologies Recommendation and conclusion Jon Anderson 64 Objective Goal – Vehicle Selection: Conducted trade studies and vehicle selection process to determine the best possible vehicle to complete the science mission. Goal - Airship: The primary mission of the airship is to function as a relay between the orbiter and the helicopter. The secondary mission of the airship is to function as a reserve platform capable of carrying out the science mission should the helicopter become inoperable. Jon Anderson 65 Performance Float mass Operational Cruse Velocity Max Velocity Min Climb/Descent Rate * Range Service Ceiling Absolute Ceiling Estimated Lifetime * Length Width Volume Mass He Needed (10% reserve) Jon Anderson 195 Kg 2.5 m/s 2.98 m/s 50 m/min 36200 km 5 km 40 km 150 days 13.83 m 3.45 m 34.47 m 27.4 kg 3 66 Vehicle Selection Mass (lower is better): This category physically rates the aerial vehicles on their expected mass. Technology Development Needs (Lower is better): This category qualitatively rates the aerial vehicles on the amount of research and development needed to make the design option feasible. Operational Risk (Lower is better): This category qualitatively rates the aerial vehicles on the “risk” associated with deploying and operating on Titan. Environmental Tolerance (Higher is better): This category qualitatively rates the aerial vehicles on their ability to withstand the environment and correct faults. Jon Anderson 67 Vehicle Selection Surface Capability (Higher is better): This category qualitatively rates the aerial vehicles on their ability to interact with the Titan surface. While all aerial vehicle options can move close to the surface, only the helicopter and combination can physically land on the surface. Mission Completion Probability (Higher is better): This category qualitatively rates the aerial vehicles on their ability to complete the mission Deployment Ability (Higher is better): This category qualitatively rates the aerial vehicles on their deployment methods. Jon Anderson 68 Vehicle Selection Category Helicopter Airship Helicopter & Airship Combination Mass 320 kg 490 kg UNK kg Technology Development Needs Medium Lower High Operational Risk Medium Low Medium Environmental Tolerance Medium High Medium Surface Capability High Medium High Mission Completion Probability Medium Medium High Deployment Ability Medium Jon Anderson High High 69 Design Constraints • Communication payload • Extra redundancy – orbiter and helicopter • Science payload • Propulsion subsystem • Mass assumptions – initial starting value • Power subsystem • MMRGT Jon Anderson 70 Assumptions Mass Assumption: • Needed initial estimate for mass of hull and structural components • Found fraction of weight for non-hull components vs NASA • Estimated initial weight • Designed airship, calculated final mass • Reiterated process with calculated mass Jon Anderson 71 350 12000000 300 10000000 250 8000000 200 6000000 150 4000000 100 2000000 50 Reynolds Number 14000000 Drag (N) Reynolds # and Drag vs Velocity Reynolds number Drag 0 0 0 1 2 3 4 5 6 7 Velocity (m/s) Jon Anderson 72 Power Required/Available vs Velocity 500 450 400 Power (W) 350 300 Power Required - Drag 250 200 Full System Operation - Power Available with 20% margin 150 Full Proplusion Operation - Power Available with 20% margin 100 50 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Velocity (m/s) Jon Anderson 73 Inflation time/percent vs Lift 1.2 350 300 1 0.8 200 0.6 150 0.4 100 0.2 Inflation Time (sec) 250 50 0 0 0 20 40 60 80 100 120 Buoyant Force/Lift (N) Jon Anderson 140 160 180 Lift 3 min inflation time 5 min inflation time 74 Deployment Airship inflation immediate • Both bayonets and main envelope • Changing ballistic coefficient • Separate via explosive shearing bolts • Immediately max velocity Jon Anderson 75 Enabling Technologies Multi Mission Radioisotope Thermal Generator • • • • Heat exchanger – not fins Centrifugal turbine – low power/mass flow levels Alternator – bearing system, no gears Centrifugal Compressor • • 5 fold increase in power Lower mass Jon Anderson 76 Recommendation and Conclusion High Altitude Design Detailed data bandwidth analysis Hull/system optimization Experments Jon Anderson 77 Questions? Jon Anderson 78 Backup slides - Mass Component Mass (kg) Mass after 20% Margin (kg) Subsystem Power 2nd Generation MMRTG Battery - 12 A h lithium Turbomachinery Turbine Compressor Piping Electric Motor Alternator 17 0.47 3.94 0.9 0.9 0.716 1.08 1.08 20.4 0.564 4.728 1.08 1.08 0.8592 1.296 1.296 26.086 31.3032 Propeller, axel, case* 5.25 6.3 Total 5.25 6.3 3 10 1.3 3.6 12 1.56 14.3 17.16 0.114 2.7 2.1 9.8 1.5 1 6 0.1368 3.24 2.52 11.76 1.8 1.2 7.2 23.214 27.8568 0.9 9 4.4 0.32 0.38 5 1.08 10.8 5.28 0.384 0.456 6 20 24 Total Propulsion Science Instruments Haze and Cloud Partical Detector Mass Spectrometer Panchromatic Visible Light Imager Total Communication X-Band Omni - LGA SDST X-up/X-down X-Band TWTA UHF Transceiver (2) UHF Omni UHF Diplexer (2) Additional Hardware (switches, cables, etc.) Total ACDS Sun Sensors IMU (2) Radar Altimeter Antennas for Radar Altimeter Absorber for Radar Altimeter Air Data System with pressure and temperature Jon Anderson Total 79 Backup slides - Mass C&DH Flight Processor Digital I/O - CAPI Board State of Health and Attitude Control Power Distribution (2) Power Control Mother Board 0.6 0.6 0.6 1.2 0.6 0.8 0.72 0.72 0.72 1.44 0.72 0.96 Power Converters (For Integrated Avionics Unit) Chassis Solid State Data Recorder 0.8 3.4 1.6 0.96 4.08 1.92 10.2 12.24 Airship Hull Gondola* Tail Section: 4 Fins and attachments* Attitude Control Helium Mass (Float at 5 km) Inflation tank for Helium* Bayonet fans and eqipment 4.57 8.4 8.4 4 29.95 19.17 5.5 5.484 10.08 10.08 4.8 35.94 23.004 6.6 Total 79.99 95.988 Inflight and during operation 8.27 9.924 Total 8.27 9.924 Total Airship Dry Mass 187.31 224.772 Total Aiship Float Mass 217.26 260.712 Total Structure Thermal Jon Anderson 80 Backup slides Power Power Required after Required (W) 20% Margin (W) Component Subsystem Power 580 W Generated Proplusion Propeller/Engine See Figure 2 See Figure 2 Total See Figure 2 See Figure 2 Fans (2) 90 108 Total 90 108 Haze and Cloud Partical Detector Mass Spectrometer Panchromatic Visible Light Imager 20 28 10 Total 58 Bayonets Science Instruments Communication UHF Transceiver 69.6 74.88 Total 74.8 Jon Anderson 89.76 81 Backup slides - Power ACDS* C&DH* Sun Sensors IMU Radar Altimeter Air Data System with pressure and temperature 0.56 22.2 37.6 7.72 Total 68.08 Flight Processor; >200 MIPS, AD750, cPCI Digital I/O - CAPI Board State of Health and Attitude Control - SMACI Power Distribution Power Control Power Converters (For Integrated Avionics Unit) Solid State Data Recorder 11.6 3.44 3.44 6.88 3.44 13.84 0.64 Total 43.28 Total Power Required without proplusion with all systems operating Straight and level 244.16 Total Power Available for Propulsion - Straight and level 335.84 Jon Anderson 82 References 1. Ravi Prakash. Design of a Long Endurance Titan VTOL Vehicle. Guggenheim School of Aerospace Engineering. 2006 2. Jeffery L Hall. Titan Airship Explorer. JPL. 2002. 3. Dr. Joel S. Levine. Titan Explorer: The Next Step in the Exploration of a Mysterious World. NASA Langley Research Center. 2005 4. Wolfram: The Mathematica Book, Wolfram Media, Inc., Fourth Edition, 1999 5. Gradshteyn/Ryzhik: Table of Integrals, Series and Products, Academic Press, Second Printing, 1981 Jon Anderson 83 Equations Buoyancy and Volume equations: B ( atm He ) g tianVAirship He patmM RTatm m V Shape and Surface Area equations: 4 V ab 2 ,4 : 1 3 3b 2 10b 2 2 S 2 b 2 abr 1 r 56b 2 b cos 1 a r b2 1 2 a Sources: Stephen Hu 84 Equations Drag and Reynolds number equations: 1/ 3 C DV , Hull D Re l .172 d 1. 2 d d .252 1.302 l l 1/ 6 Re 1 U 2V 2 / 3C DV , Hull 2 V (2b) Thrust and power available equations: Powerrequired DU foward Stephen Hu 85 Diagram of Airship Stephen Hu 86 Team Member Stephen Hu Deployment Vehicle Selection Helicopter Design Hours Worked: 98 Stephen Hu 87 Helicopter Design Introduction General Characteristics Constraints Deployment Conclusions Recommendations Stephen Hu 88 Introduction 1. Investigation of the surface and lakes of Titan 2. VTOL capability 3. Dependable performance in hostile environments 4. Able to last four months under constant operation Stephen Hu 89 Constraints • Environment – – – – Temperature Wind Solar Energy Atmospheric Density • Volume/Storage – Diameter of Heat Shield – Airship Storage Stephen Hu 90 General Characteristics Vehicle: Helicopter Type: Coaxial Number of Blades per rotor: 2 blades Airfoil: NACA 0012 Stephen Hu 91 Deployment • Post-Airship Separation • Generator startup • Freefall rotor startup • Heat Shield separation Stephen Hu 92 Mass and Power Constraints Power Required to Hover (W) 1400 1200 1000 800 600 400 Power Required to Hover 200 Power Available 0 0 50 100 150 200 250 300 350 Mass (kg) Stephen Hu 93 Blade Radius vs. Power Required Power Required to Hover (W) 3000 m=155.4 2500 2000 m=186.5 1500 1000 500 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 Blade Radius (m) Stephen Hu 94 Forward Velocity vs. Power Required 1400 Power Required (W) 1200 1000 800 600 m=155.4 400 m=186.5 200 Power Available 0 0 1 2 3 4 5 6 7 8 9 10 Forward Velocity (m/s) Stephen Hu 95 Conclusions Characteristics/Performance Mass (kg) Payload Mass (kg) Expected 155.4 15.00 Contingency (20%) 186.5 18.00 Rotor Diameter (m) Main Blade Chord (m) Fuselage Length (m) Fuselage Height (m) Total Height (m) 1.364 0.091 2.56 0.77 1 1.426 0.095 2.56 0.77 Total Width (m) Max Climb Rate (m/s) Spinup Time (s) Max Cruise Velocity (m/s) 0.8 2.292 7.961 7.46 Optimal Cruise Velocity (m/s) Range (km)* 3.1 188.0 Altitude (km) 15 Stephen Hu 1 0.8 1.349 9.096 6.95 3.6 175.1 10 96 Recommendations • More in-depth aerodynamic design • Materials • Payload • Deployment Stephen Hu 97 References 1. "The Vertical Profile of Winds on Titan." www.nature.com. 8 Dec. 2005. Nature: International Weekly Journal of Science. <http://www.nature.com/nature/journal/v438/n7069/full/nature0 4060.html>. 2. Wright, Henry S. Design of a Long Endurance Titan VTOL Vehicle. Georgia Institute of Technology. <https://wiki.umn.edu/pub/titanedd/deployment/vtol_design_pa per.pdf>. 3. Leishman, Gordon. Principles of Helicopter Aerodynamics. Cambridge UP, 2006. Stephen Hu 98 FMEA • Aeroshell separation failure, probability low, mission failure • Helicopter failure, probability medium, some loss of data, airship has some redundancy •Airship failure, probability low, shorter data transfer window, some instrument loss • Parachute failure, probability low, possible mission failure Andrew Welsh 99 FMEA •Helicopter one engine failure, probability low, extremely decreased functionality • Helicopter two engine failure, probability low, helicopter failure • Heat shield failure, probability low, mission failure • Incorrect entry position, probability medium, possible mission failure or wasted time for airship and helicopter to reach intended position Andrew Welsh 100 FMEA Environmental, Societal, and Global Impacts: • Launch failure, environmental radiation contamination or death, find alternate power source or plant a tree • Noisy launch, plant a tree • Excessive exhaust from launch, plant a tree Andrew Welsh 101 FMEA • Life found on Titan causes panic, hide the truth, prepare public for truth, military law • Contaminate Titan with Earth organisms, sterilization • Scientific breakthroughs eliminate human jobs, socialism Andrew Welsh 102