Pawel Swica1 Entry/Integration Hours Worked: Team Member Pawel Swica

2 Objectives Determine interplanetary orbit path and entry speed Research heat shield materials and heating formulae Determine shield mass based on best material Determine entry position and likely landing area

Pawel Swica3 Orbit Evaluation Study yielded an entry velocity of 3.6 km/s However, the orbit relied on a large change in velocity at earth orbit Published materials* detailed how an ion engine powered by solar cells coupled with planetary assist maneuvers would make launch less expensive Published entry speed of 6.5 km/s was used Following slides detail study that in the end was not used * “ Titan Explorer: The Next Step in the Exploration of a Mysterious World, ” Levine, Joel S., Wright, Henry S.; NASA Langley Research Center

Pawel Swica4 Relevant Equations For Orbit Orbital Mechanics for Engineering Students, Curtis, Howard D.; 2005

Pawel Swica5 Orbit Diagrams

Pawel Swica6 Orbit Diagrams

Pawel Swica7 Orbit Diagrams

Pawel Swica8 Resulting trade study

Pawel Swica9 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) * “Updated TPS Requirements for Missions to Titan,” Laub, B and Chen, Y.-K.; NASA Ames Research Center

Pawel Swica10 Relevant Equations Dynamics and Thermodynamics of Planetary Entry, W.H.T. Loh, Prentice Hall Space Technology Series, Heating per unit area -Atmospheric constant -Radius of shield -Sea level or ground density C Worked 50/50 with Nick DeLucca

Pawel Swica11 Heat Shield Results Results were taken from Laub paper for mass and material SRAM-14 material and less radiative heating gave up to 98 kg mass savings from previous study* which gave a mass of 153 kg Heat shield mass will be approximately 55 kg with shape detailed Back aero shell remains the same as in previous study*, given as weighing 29 kg with shape detailed * “Titan Explorer: The Next Step in the Exploration of a Mysterious World,” Levine, Joel S., Wright, Henry S.; NASA Langley Research Center

Pawel Swica12 Heating Graph and Shield Dimensions Figure 4. Entry heating graphFigure 5. Aeroshell model “Updated TPS Requirements for Missions to Titan,” Laub, B and Chen, Y.-K.; NASA Ames Research Center

Pawel Swica13 TPS Materials Study “Aeroshell Design Techniques for Aerocapture Entry Vehicles,” Dyke, R. Eric, Hrinda, Glenn A.; NASA Langley Research Center, AIAA

Pawel Swica14 Entry Corridor Our gathered materials were insufficient 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 º down at entry interface (1000 km) with 5º margin in either direction Corridor defined in AIAA , upper bound defined by “skip-out,” lower bound defined by unmanageable heating Modeling in simulink showed successful entry in this corridor with some additional margin “Titan Explorer Entry, Descent, and Landing Trajectory Design,” Fisch, Lindberg, and Lockwood; AAS February 4, 2006 “Approach Navigation for a Titan Aerocapture Orbiter,” Haw, Robert J.; Jet Propulsion Laboratory; AIAA

Pawel Swica15 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 Swica16 Relevant Calculations Orbital Mechanics for Engineering Students, Curtis, Howard D.; 2005

Pawel Swica17 Results Ontario Lacus lies at latitude 72º* S and the downstream distance given by simulink is 1200 km Probe can land as close as 181 km from Ontario Lacus If the planet is facing the wrong way, this distance could become almost 1800 km Depends on timing the approach just right, which is beyond the scope of our analysis Either way, distance is within travel range of the probe Group mate Jon Anderson estimated a 30,000 km range Also, adjusting to land at Ontario Lacus is well within the entry corridor * “NASA - NASA Confirms Liquid Lake On Saturn Moon,”

Pawel Swica18 Vpython Model To verify results a Vpython (iterative visual modeling language) orbit script was modified to match the precise conditions given by the calculations To ensure accuracy, starting point is about 180 Titan radii out Success of program and calculations indicated by probe reaching conditions given by publication (50º at entry interface) Titan and entry interface shown to scale, probe enlarged

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