@article{BaaderBoxbergChenetal.2023, author = {Baader, Fabian and Boxberg, Marc S. and Chen, Qian and F{\"o}rstner, Roger and Kowalski, Julia and Dachwald, Bernd}, title = {Field-test performance of an ice-melting probe in a terrestrial analogue environment}, series = {Icarus}, journal = {Icarus}, number = {409}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.icarus.2023.115852}, pages = {Artikel 115852}, year = {2023}, abstract = {Melting probes are a proven tool for the exploration of thick ice layers and clean sampling of subglacial water on Earth. Their compact size and ease of operation also make them a key technology for the future exploration of icy moons in our Solar System, most prominently Europa and Enceladus. For both mission planning and hardware engineering, metrics such as efficiency and expected performance in terms of achievable speed, power requirements, and necessary heating power have to be known. Theoretical studies aim at describing thermal losses on the one hand, while laboratory experiments and field tests allow an empirical investigation of the true performance on the other hand. To investigate the practical value of a performance model for the operational performance in extraterrestrial environments, we first contrast measured data from terrestrial field tests on temperate and polythermal glaciers with results from basic heat loss models and a melt trajectory model. For this purpose, we propose conventions for the determination of two different efficiencies that can be applied to both measured data and models. One definition of efficiency is related to the melting head only, while the other definition considers the melting probe as a whole. We also present methods to combine several sources of heat loss for probes with a circular cross-section, and to translate the geometry of probes with a non-circular cross-section to analyse them in the same way. The models were selected in a way that minimizes the need to make assumptions about unknown parameters of the probe or the ice environment. The results indicate that currently used models do not yet reliably reproduce the performance of a probe under realistic conditions. Melting velocities and efficiencies are constantly overestimated by 15 to 50 \% in the models, but qualitatively agree with the field test data. Hence, losses are observed, that are not yet covered and quantified by the available loss models. We find that the deviation increases with decreasing ice temperature. We suspect that this mismatch is mainly due to the too restrictive idealization of the probe model and the fact that the probe was not operated in an efficiency-optimized manner during the field tests. With respect to space mission engineering, we find that performance and efficiency models must be used with caution in unknown ice environments, as various ice parameters have a significant effect on the melting process. Some of these are difficult to estimate from afar.}, language = {en} } @article{BlomeSeboldtDachwaldetal.2004, author = {Blome, Hans-Joachim and Seboldt, Wolfgang and Dachwald, Bernd and Richter, Lutz}, title = {Proposal for an integrated European Space Exploration Study}, series = {Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch}, journal = {Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch}, publisher = {Univelt}, address = {San Diego, Calif.}, isbn = {0-87703-523-7}, pages = {XI, 432 S. : Ill., graph. Darst.}, year = {2004}, language = {en} } @article{CampenKowalskiLyonsetal.2019, author = {Campen, R. and Kowalski, Julia and Lyons, W.B. and Tulaczyk, S. and Dachwald, Bernd and Pettit, E. and Welch, K. A. and Mikucki, J.A.}, title = {Microbial diversity of an Antarctic subglacial community and high-resolution replicate sampling inform hydrological connectivity in a polar desert}, series = {Environmental Microbiology}, journal = {Environmental Microbiology}, number = {accepted article}, publisher = {Wiley}, address = {Weinheim}, issn = {1462-2920}, doi = {10.1111/1462-2920.14607}, year = {2019}, language = {en} } @article{Dachwald2005, author = {Dachwald, Bernd}, title = {Optimization of very-low-thrust trajectories using evolutionary neurocontrol}, series = {Acta Astronautica. 57 (2005), H. 2-8}, journal = {Acta Astronautica. 57 (2005), H. 2-8}, isbn = {0094-5765}, pages = {175 -- 185}, year = {2005}, language = {en} } @article{Dachwald2004, author = {Dachwald, Bernd}, title = {Minimum Transfer Times for Nonperfectly Reflecting Solar Sailcraft}, series = {Journal of Spacecraft and Rockets. 41 (2004), H. 4}, journal = {Journal of Spacecraft and Rockets. 41 (2004), H. 4}, isbn = {0022-4650}, pages = {693 -- 695}, year = {2004}, language = {en} } @article{Dachwald2005, author = {Dachwald, Bernd}, title = {Optimal Solar Sail Trajectories for Missions to the Outer Solar System}, series = {Journal of guidance, control, and dynamics. 28 (2005), H. 6}, journal = {Journal of guidance, control, and dynamics. 28 (2005), H. 6}, isbn = {0162-3192}, pages = {1187 -- 1193}, year = {2005}, language = {en} } @article{Dachwald2004, author = {Dachwald, Bernd}, title = {Optimization of Interplanetary Solar Sailcraft Trajectories Using Evolutionary Neurocontrol}, series = {Journal of guidance, control, and dynamics. 27 (2004), H. 1}, journal = {Journal of guidance, control, and dynamics. 27 (2004), H. 1}, isbn = {0162-3192}, pages = {66 -- 72}, year = {2004}, language = {en} } @article{Dachwald1996, author = {Dachwald, Bernd}, title = {Entwicklung sicherer und wartbarer Software f{\"u}r den Eurofighter}, series = {Soldat und Technik : Strategie und Technik, Sicherheit (1996)}, journal = {Soldat und Technik : Strategie und Technik, Sicherheit (1996)}, isbn = {0038-0989}, pages = {663 -- 668}, year = {1996}, language = {de} } @article{Dachwald2004, author = {Dachwald, Bernd}, title = {Interplanetary Mission Analysis for Non-Perfectly Reflecting Solar Sailcraft Using Evolutionary Neurocontrol}, series = {Astrodynamics 2003 : proceedings of the AAS/AIAA Astrodynamics Conference held August 3 - 7, 2003, Big Sky, Montana / ed. by Jean de Lafontaine. - Pt. 2. - (Advances in the astronautical sciences ; 116,2)}, journal = {Astrodynamics 2003 : proceedings of the AAS/AIAA Astrodynamics Conference held August 3 - 7, 2003, Big Sky, Montana / ed. by Jean de Lafontaine. - Pt. 2. - (Advances in the astronautical sciences ; 116,2)}, publisher = {Univelt}, address = {San Diego, Calif.}, isbn = {0-87703-509-1}, pages = {1247 -- 1262}, year = {2004}, language = {en} } @article{Dachwald2003, author = {Dachwald, Bernd}, title = {Verwendung eines neuronalen Reglers und evolution{\"a}rer Algorithmen zur Berechnung optimaler interplanetarer Sonnenseglerbahnen}, series = {Deutscher Luft- und Raumfahrtkongress 2003 : M{\"u}nchen, 17. bis 20. November 2003, Motto: 100 Jahre Motorflug - 112 Jahre Menschenflug: Visionen gestalten Zukunft / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 1. - (Jahrbuch ... der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt)}, journal = {Deutscher Luft- und Raumfahrtkongress 2003 : M{\"u}nchen, 17. bis 20. November 2003, Motto: 100 Jahre Motorflug - 112 Jahre Menschenflug: Visionen gestalten Zukunft / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 1. - (Jahrbuch ... der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt)}, address = {Bonn}, pages = {211 -- 218}, year = {2003}, language = {de} } @article{Dachwald2004, author = {Dachwald, Bernd}, title = {Low-Thrust Trajectory Optimization and Interplanetary Mission Analysis Using Evolutionary Neurocontrol}, series = {Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Br{\"u}cke f{\"u}r eine wissensbasierte Gesellschaft / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt)}, journal = {Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Br{\"u}cke f{\"u}r eine wissensbasierte Gesellschaft / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt)}, address = {Bonn}, pages = {917 -- 926}, year = {2004}, language = {en} } @article{Dachwald2004, author = {Dachwald, Bernd}, title = {Evolutionary Neurocontrol: A Smart Method for Global Optimization of Low-Thrust Trajectories}, series = {22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)}, journal = {22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)}, publisher = {American Inst. of Aeronautics and Astronautics}, address = {Reston, Va.}, pages = {2 CD-ROMs}, year = {2004}, language = {en} } @article{Dachwald2004, author = {Dachwald, Bernd}, title = {Optimal Solar Sail Trajectories for Missions to the Outer Solar System}, series = {22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)}, journal = {22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)}, publisher = {American Inst. of Aeronautics and Astronautics}, address = {Reston, Va.}, pages = {2 CD-ROMs}, year = {2004}, language = {en} } @article{Dachwald2005, author = {Dachwald, Bernd}, title = {Optimization of very-low-thrust trajectories using evolutionary neurocontrol}, series = {Acta Astronautica}, volume = {57}, journal = {Acta Astronautica}, number = {2-8}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, isbn = {1879-2030}, pages = {175 -- 185}, year = {2005}, abstract = {Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric).}, language = {en} } @article{DachwaldBallUlamecetal.2009, author = {Dachwald, Bernd and Ball, Andrew J. and Ulamec, Stephan and Price, Michael E.}, title = {A small mission for in situ exploration of a primitive binary near-Earth asteroid / Ball, Andrew J. ; Ulamec, Stephan ; Dachwald, Bernd ; Price, Michael E. ; [u.a.]}, series = {Advances in Space Research. 43 (2009), H. 2}, journal = {Advances in Space Research. 43 (2009), H. 2}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0273-1177}, pages = {317 -- 324}, year = {2009}, language = {en} } @article{DachwaldBaturkinCoverstoneetal.2006, author = {Dachwald, Bernd and Baturkin, Volodymyr and Coverstone, Victoria L. and Dietrich, Benjamin and Garbe, Gregory P. and G{\"o}rlich, Marianne and Leipold, Manfred and Lura, Franz and Macdonald, Malcolm and McInnes, Colin R. and Mengali, Giovanni and Quatra, Alessandro A. and Rios-Reyes, Leonel and Scheeres, Daniel J. and Seboldt, Wolfgang and Wie, Bong}, title = {Potential Effects of Optical Solar Sail Degradation on Interplanetary Trajectory Design}, series = {Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)}, journal = {Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)}, publisher = {Univelt}, address = {San Diego, Calif.}, isbn = {0-87703-527-X}, pages = {2569 -- 2592}, year = {2006}, language = {en} } @article{DachwaldCarnelliVasile2006, author = {Dachwald, Bernd and Carnelli, I. and Vasile, M.}, title = {Low-Thrust Gravity Assist Trajectory Optimization Using Evolutionary Neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile ...}, series = {Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)}, journal = {Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)}, publisher = {Univelt}, address = {San Diego, Calif.}, isbn = {0-87703-527-X}, pages = {1911 -- 1928}, year = {2006}, language = {en} } @article{DachwaldCarnelliVasile2007, author = {Dachwald, Bernd and Carnelli, I. and Vasile, M.}, title = {Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile}, series = {IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore}, journal = {IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {978-1-424-41339-3}, pages = {965 -- 972}, year = {2007}, language = {en} } @article{DachwaldCarnelliVasile2006, author = {Dachwald, Bernd and Carnelli, I. and Vasile, M.}, title = {Evolutionary Neurocontrol as a Novel Method for Low-Thrust Gravity Assist Trajectory Optimization / I. Carnelli ; B. Dachwald ; M. Vasile}, series = {Proceedings of the Twenty-Fifth International Symposium on Space Technology and Science (Selected papers) : Kanazawa, [June 4 through June 11, 2006, at Kanazawa-shi Kanko Kaikan in Kanazawa city] / [Japan Society for Aeronautical and Space Sciences. Kohtaro Matsumoto [ed.-in-chief]}, journal = {Proceedings of the Twenty-Fifth International Symposium on Space Technology and Science (Selected papers) : Kanazawa, [June 4 through June 11, 2006, at Kanazawa-shi Kanko Kaikan in Kanazawa city] / [Japan Society for Aeronautical and Space Sciences. Kohtaro Matsumoto [ed.-in-chief]}, publisher = {JSASS}, address = {Tokyo}, isbn = {4-99005-002-9}, pages = {569 -- 574}, year = {2006}, language = {en} } @article{DachwaldCarnelliVasile2009, author = {Dachwald, Bernd and Carnelli, Ian and Vasile, Massimiliano}, title = {Evolutionary Neurocontrol: A Novel Method for Low-Thrust Gravity-Assist Trajectory Optimization / Carnelli, Ian ; Dachwald, Bernd ; Vasile, Massimiliano}, series = {Journal of guidance control and dynamics. 32 (2009), H. 2}, journal = {Journal of guidance control and dynamics. 32 (2009), H. 2}, publisher = {AIAA}, address = {Reston, Va.}, isbn = {0731-5090}, pages = {616 -- 625}, year = {2009}, language = {en} }