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LOFAR on the Moon: Mission Configuration and Orbit Design

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LOFAR on the Moon: Mission Configuration and Orbit Design LOFAR on the Moon: Mission Configuration and Orbit Design Maximizing the Payload Mass Using Chemical or Electri- cal Propulsion Lucas Antignac May 12, 2015 Master of Science Thesis Aerospace Engineering - Space Exploration LOFAR on the Moon: Mission Configuration and Orbit Design Maximizing the Payload Mass Using Chemical or Electrical Propulsion Master of Science Thesis For the degree of Master of Science in Aerospace Engineering at the Delft University of Technology Lucas Antignac (4176189) Under the supervision of: Ir. R. Noomen Ir. H. Cruijssen Ir. L. Meijer May 12, 2015 Faculty of Aerospace Engineering · Delft University of Technology Abstract Unperturbed observation of deep space radio waves is impossible to achieve from Earth but could be managed if the instruments were positioned in a place shielded from Earth, such as the far side of the Moon or the Shackleton crater, situated at its South Pole. In order to keep the costs of such a mission as low as possible, the VEGA launcher needs to be used. This MSc Thesis studies the possible mission designs and trajectories to land a minimum of 150 kg of payload in such a place. For the eight mission scenarios considered, the spacecraft can either use a Chemical Propulsion System (CPS) or an Electric Propulsion System (EPS) for the transfer to Low Lunar Orbit (LLO), the spacecraft can either circularize around the Moon in a polar orbit or in an orbit situated in the lunar orbital plane, and the relay can either be sent to the Lagrangian point L2 (L2) or be landed on the Moon. After preselecting the four feasible mission scenarios, a Matlab program was coded to simulate the trajectories flown from Low Earth Orbit (LEO) to LLO using either a CPS or an EPS, the trajectory from LLO to L2 using a CPS which is applicable to certain mission scenarios only, and the trajectory for the descent and landing also using a CPS. The inclination of the lunar orbital plane with respect to the launching site varying during the year, it was chosen to take the worst-case scenario for this report. The subsystem masses were then assessed to determine the payload mass that can be placed on the Moon. It was found that with the most successful CPS mission 34 kg of payload could be placed on the rim of the Shackleton crater, while 107 kg could be placed at that same place when using an EPS. For both cases, no relay module was sent to L2 and the spacecraft circularized around the Moon in a polar orbit. Even though the payload mass does not meet the 150 kg requirement, the reader should not forget that this study belongs to the preliminary design phase of the mission: he could therefore look into the recommendations for further work to alter several parameters that could change the outcome of this report. Master of Science Thesis Lucas Antignac ii Abstract Lucas Antignac Master of Science Thesis List of Acronyms ADS-NL Airbus Defence and Space Netherlands AOCS Attitude and Orbital Control System CCW Counter-Clockwise CPS Chemical Propulsion System CW Clockwise DL Descent and Landing EPS Electric Propulsion System ESA European Space Agency GTO Geostationary Transfer Orbit L2 Lagrangian point L2 LEO Low Earth Orbit LLO Low Lunar Orbit LOFAR LOw Frequency ARray MSc Master of Science OBC On Board Computer PCU Power Conditioning Unit SOI Sphere Of Influence SPS Stackable Platform System TCS Thermal Control System TTC Telemetry, Tracking and Command Master of Science Thesis Lucas Antignac iv List of Acronyms TU Delft Delft University of Technology VEGA Vettore Europeo di Generazione Avanzata (Advanced Generation European Carrier Rocket) Lucas Antignac Master of Science Thesis Table of Contents Abstract i List of Acronyms iii Preface ix Acknowledgments xi 1 General Introduction1 2 The Mission3 2-1 Purposes of LOFAR on the Moon.......................... 3 2-2 Mission outline.................................... 5 2-2-1 VEGA launcher............................... 5 2-2-2 Earth-Moon transfer............................. 6 2-2-3 Landing the payload on the Moon..................... 7 2-2-4 Relay options................................ 7 2-3 Goal of this MSc thesis............................... 8 2-4 Optional mission scenarios............................. 9 2-4-1 Mission design considerations, assumptions and constraints........ 9 2-4-2 Study of the different mission scenarios.................. 10 2-4-3 Summary.................................. 12 2-5 Approach for this study............................... 13 2-5-1 Transfer orbits................................ 13 2-5-2 Spacecraft architecture........................... 13 2-5-3 Transfer orbit representation........................ 17 Master of Science Thesis Lucas Antignac vi Table of Contents 3 From LEO to LLO Using CPS 19 3-1 Introduction..................................... 19 3-2 Discretization of the VEGA performance chart................... 19 3-3 Optimal parking orbit around the Earth...................... 21 3-3-1 Considerations................................ 21 3-3-2 Matlab solving................................ 22 3-4 Simplification of the problem: from 3D to 2D................... 24 3-5 The in-plane three-body problem.......................... 26 3-5-1 Equations of motion............................. 26 3-5-2 Explanation of the Matlab program..................... 29 3-5-3 Calculations: inputs and results....................... 33 3-5-4 Minimum value of ∆Vtot .......................... 36 3-6 Results and conclusions............................... 37 4 From LEO to LLO Using EPS 39 4-1 Introduction..................................... 39 4-2 Procedure...................................... 39 4-2-1 Transfer orbit................................ 40 4-2-2 Perturbations................................ 41 4-2-3 Acceleration provided by the engines.................... 42 4-3 Constraints and assumptions............................ 43 4-3-1 Available power............................... 43 4-3-2 Time constraint............................... 45 4-3-3 Transfer geometry and constraints..................... 46 4-3-4 Constraints on the engines......................... 48 4-4 Apogee raising.................................... 50 4-4-1 The “spiral out” orbit............................ 50 4-4-2 Influences of thrust, specific impulse and altitude of parking orbit on the transfer time................................. 50 4-4-3 First engine selection: transfer time.................... 53 4-4-4 Second engine selection: mass at lunar altitude.............. 54 4-4-5 Time in Van Allen belts........................... 56 4-5 Lunar capture.................................... 58 4-6 Results........................................ 63 5 From LLO to the Lagrangian Point L2 65 5-1 Introduction..................................... 65 5-2 Theorem of image trajectories........................... 66 5-3 Procedure...................................... 67 5-4 Computations.................................... 69 5-4-1 From L2 to LLO............................... 69 5-4-2 The image orbit............................... 71 5-5 Overall results and conclusions........................... 73 Lucas Antignac Master of Science Thesis Table of Contents vii 6 From LLO to Lunar Surface 75 6-1 Introduction..................................... 75 6-2 Descent....................................... 76 6-3 Hovering and landing................................ 79 6-4 Overall results.................................... 80 7 Best Mission Scenario 81 7-1 Introduction..................................... 81 7-2 Different mission scenarios............................. 81 7-3 Mass left in LLO................................... 83 7-4 Mission Scenarios C2, C3 and C4.......................... 85 7-5 Mission Scenario E3................................. 86 7-5-1 Overview of transfer parameters...................... 86 7-5-2 Electrical stage............................... 86 7-5-3 Lander.................................... 87 7-6 Results........................................ 89 8 Conclusion and Recommendations 93 8-1 General conclusion.................................. 93 8-2 Recommendations for further work......................... 94 A Old Preface 97 Master of Science Thesis Lucas Antignac viii Table of Contents Lucas Antignac Master of Science Thesis Preface [An unconventional preface was first written before being judged of unprofessional quality. This old preface can be found in AppendixA.] This Master of Science (MSc) thesis was carried out at the company Airbus Defence and Space Netherlands (ADS-NL), formerly called Dutch Space, situated in Leiden, The Netherlands. This MSc thesis is supervised by Ron Noomen, assistant professor at the disciplinary group Astrodynamics and Space Missions of the Aerospace Engineering faculty at Delft University of Technology (TU Delft), together with Henk Cruijssen, Systems Engineer at the Research and Development Projects department of ADS-NL and Lex Meijer, Lead Engineer of the Operations, Optical and Electrical Engineering department of ADS-NL. Master of Science Thesis Lucas Antignac x Preface Lucas Antignac Master of Science Thesis Acknowledgments I would like to take this opportunity to thank my TU Delft supervisor, Ir. R. Noomen for guiding me through this work, and more generally my Master of Science program. Being my Master coordinator, he helped me out in the completion of my studies from the first day until the end of my Master of Science Thesis and challenged the results of my thesis all along its completion. I am also grateful to Ir. H. Cruijssen, systems engineer at Airbus
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