@inproceedings{DachwaldKahleWie2007,
  author    = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong},
  title     = {Head-on impact deflection of NEAs: a case study for 99942 Apophis},
  series = {Planetary Defense Conference 2007},
  booktitle = {Planetary Defense Conference 2007},
  pages     = {1 -- 12},
  year      = {2007},
  abstract  = {Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value},
  language  = {en}
}
@inproceedings{HallmannHeideckerSchlottereretal.2016,
  author    = {Hallmann, Marcus and Heidecker, Ansgar and Schlotterer, Markus and Dachwald, Bernd},
  title     = {GTOC8: results and methods of team 15 DLR},
  series = {26th AAS/AIAA Space Flight Mechanics Meeting, Napa, CA},
  booktitle = {26th AAS/AIAA Space Flight Mechanics Meeting, Napa, CA},
  year      = {2016},
  abstract  = {This paper describes the results and methods used during the 8th Global Trajectory Optimization Competition (GTOC) of the DLR team. Trajectory optimization is crucial for most of the space missions and usually can be formulated as a global optimization problem. A lot of research has been done to different type of mission problems. The most demanding ones are low thrust transfers with e.g. gravity assist sequences. In that case the optimal control problem is combined with an integer problem. In most of the GTOCs we apply a filtering of the problem based on domain knowledge.},
  language  = {en}
}
@incollection{McInnesBothmerDachwaldetal.2014,
  author    = {McInnes, Colin R. and Bothmer, Volker and Dachwald, Bernd and Geppert, Ulrich R. M. E. and Heiligers, Jeannette and Hilgers, Alan and Johnson, Les and Macdonald, Malcolm and Reinhard, Ruedeger and Seboldt, Wolfgang and Spietz, Peter},
  title     = {Gossamer roadmap technology reference study for a Sub-L1 Space Weather Mission},
  series = {Advances in solar sailing},
  booktitle = {Advances in solar sailing},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)},
  pages     = {227 -- 242},
  year      = {2014},
  abstract  = {A technology reference study for a displaced Lagrange point space weather mission is presented. The mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy to deliver a low mass platform and payload which can be accommodated on the DLR/ESA Gossamer-3 technology demonstration mission. A direct escape from Geostationary Transfer Orbit is assumed with the sail deployed after the escape burn. The use of a miniaturized, low mass platform and payload then allows the Gossamer-3 solar sail to potentially double the warning time of space weather events. The mission profile and mass budgets will be presented to achieve these ambitious goals.},
  language  = {en}
}
@incollection{MacdonaldMcGrathAppourchauxetal.2014,
  author    = {Macdonald, Malcolm and McGrath, C. and Appourchaux, T. and Dachwald, Bernd and Finsterle, W. and Gizon, L. and Liewer, P. C. and McInnes, Colin R. and Mengali, G. and Seboldt, W. and Sekii, T. and Solanki, S. K. and Velli, M. and Wimmer-Schweingruber, R. F. and Spietz, Peter and Reinhard, Ruedeger},
  title     = {Gossamer roadmap technology reference study for a solar polar mission},
  series = {Advances in solar sailing},
  booktitle = {Advances in solar sailing},
  editor    = {Macdonald, Malcolm},
  publisher = {Springer},
  address   = {Berlin, Heidelberg},
  isbn      = {978-3-642-34906-5},
  doi       = {10.1007/978-3-642-34907-2_17},
  pages     = {243 -- 257},
  year      = {2014},
  abstract  = {A technology reference study for a solar polar mission is presented. The study uses novel analytical methods to quantify the mission design space including the required sail performance to achieve a given solar polar observation angle within a given timeframe and thus to derive mass allocations for the remaining spacecraft sub-systems, that is excluding the solar sail sub-system. A parametric, bottom-up, system mass budget analysis is then used to establish the required sail technology to deliver a range of science payloads, and to establish where such payloads can be delivered to within a given timeframe. It is found that a solar polar mission requires a solar sail of side-length 100-125 m to deliver a 'sufficient value' minimum science payload, and that a 2.5 μm sail film substrate is typically required, however the design is much less sensitive to the boom specific mass.},
  language  = {en}
}
@incollection{DachwaldBoehnhardtBrojetal.2014,
  author    = {Dachwald, Bernd and Boehnhardt, Herrmann and Broj, Ulrich and Geppert, Ulrich R. M. E. and Grundmann, Jan-Thimo and Seboldt, Wolfgang and Seefeldt, Patric and Spietz, Peter and Johnson, Les and K{\"u}hrt, Ekkehard and Mottola, Stefano and Macdonald, Malcolm and McInnes, Colin R. and Vasile, Massimiliano and Reinhard, Ruedeger},
  title     = {Gossamer roadmap technology reference study for a multiple NEO Rendezvous Mission},
  series = {Advances in solar sailing},
  booktitle = {Advances in solar sailing},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)},
  pages     = {211 -- 226},
  year      = {2014},
  abstract  = {A technology reference study for a multiple near-Earth object (NEO) rendezvous mission with solar sailcraft is currently carried out by the authors of this paper. The investigated mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy based on the DLR/ESA Gossamer technology. The main scientific objective of the mission is to explore the diversity of NEOs. After direct interplanetary insertion, the solar sailcraft should—within less than 10 years—rendezvous three NEOs that are not only scientifically interesting, but also from the point of human spaceight and planetary defense. In this paper, the objectives of the study are outlined and a preliminary potential mission profile is presented.},
  language  = {en}
}
@inproceedings{Dachwald2005,
  author    = {Dachwald, Bernd},
  title     = {Global optimization of low-thrust space missions using evolutionary neurocontrol},
  series = {Proceedings of the international workshop on global optimization},
  booktitle = {Proceedings of the international workshop on global optimization},
  pages     = {85 -- 90},
  year      = {2005},
  abstract  = {Low-thrust space propulsion systems enable flexible high-energy deep space missions, but the design and optimization of the interplanetary transfer trajectory is usually difficult. It involves much experience and expert knowledge because the convergence behavior of traditional local trajectory optimization methods depends strongly on an adequate initial guess. Within this extended abstract, evolutionary neurocontrol, a method that fuses artificial neural networks and evolutionary algorithms, is proposed as a smart global method for low-thrust trajectory optimization. It does not require an initial guess. The implementation of evolutionary neurocontrol is detailed and its performance is shown for an exemplary mission.},
  language  = {en}
}
@incollection{DachwaldOhndorf2019,
  author    = {Dachwald, Bernd and Ohndorf, Andreas},
  title     = {Global optimization of continuous-thrust trajectories using evolutionary neurocontrol},
  series = {Modeling and Optimization in Space Engineering},
  booktitle = {Modeling and Optimization in Space Engineering},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-10501-3},
  doi       = {10.1007/978-3-030-10501-3_2},
  pages     = {33 -- 57},
  year      = {2019},
  abstract  = {Searching optimal continuous-thrust trajectories is usually a difficult and time-consuming task. The solution quality of traditional optimal-control methods depends strongly on an adequate initial guess because the solution is typically close to the initial guess, which may be far from the (unknown) global optimum. Evolutionary neurocontrol attacks continuous-thrust optimization problems from the perspective of artificial intelligence and machine learning, combining artificial neural networks and evolutionary algorithms. This chapter describes the method and shows some example results for single- and multi-phase continuous-thrust trajectory optimization problems to assess its performance. Evolutionary neurocontrol can explore the trajectory search space more exhaustively than a human expert can do with traditional optimal-control methods. Especially for difficult problems, it usually finds solutions that are closer to the global optimum. Another fundamental advantage is that continuous-thrust trajectories can be optimized without an initial guess and without expert supervision.},
  language  = {en}
}
@article{DachwaldTuryshevDittusetal.2005,
  author    = {Dachwald, Bernd and Turyshev, Slava G. and Dittus, H. and Shao, M. [u.a.]},
  title     = {Fundamental Physics with the Laser Astrometric Test Of Relativity / S.G. Turyshev ; H. Dittus ; M. Shao ... B.Dachwald ...},
  series = {Proceedings of the 39th ESLAB Symposium "Trends in Space Science and Cosmic Vision 2020" : 19 - 21 April 2005, ESTEC, Noordwijk, the Netherlands / European Space Agency. [Comp. by: F. Favata ...] . - (ESA SP ; 588)},
  journal   = {Proceedings of the 39th ESLAB Symposium "Trends in Space Science and Cosmic Vision 2020" : 19 - 21 April 2005, ESTEC, Noordwijk, the Netherlands / European Space Agency. [Comp. by: F. Favata ...] . - (ESA SP ; 588)},
  publisher = {ESA Publ. Div.},
  address   = {Noordwijk},
  isbn      = {9290928999},
  pages     = {8 -- 11},
  year      = {2005},
  language  = {en}
}
@inproceedings{GrundmannBauerBieleetal.2015,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Biele, Jens and Cordero, Frederico and Dachwald, Bernd and Koncz, Alexander and Krause, Christian and Mikschl, Tobias and Montenegro, Sergio and Quantius, Dominik and Ruffer, Michael and Sasaki, Kaname and Schmitz, Nicole and Seefeldt, Patric and T{\´o}th, Norbert and Wejmo, Elisabet},
  title     = {From Sail to Soil - Getting Sailcraft Out of the Harbour on a Visit to One of Earth's Nearest Neighbours},
  series = {4th IAA Planetary Denfense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy},
  booktitle = {4th IAA Planetary Denfense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy},
  pages     = {20 S.},
  year      = {2015},
  language  = {en}
}
@inproceedings{GrundmannBauerBodenetal.2019,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Boden, Ralf and Ceriotti, Matteo and Chand, Suditi and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Heiligers, Jeannette and Herč{\´i}k, David and H{\´e}rique, Alain and Ho, Tra-Mi and Jahnke, Rico and Kofman, Wlodek and Lange, Caroline and Lichtenheldt, Roy and McInnes, Colin and Meß, Jan-Gerd and Mikschl, Tobias and Mikulz, Eugen and Montenegro, Sergio and Moore, Iain and Pelivan, Ivanka and Peloni, Alessandro and Plettemeier, Dirk and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Riemann, Johannes and Rogez, Yves and Ruffer, Michael and Sasaki, Kaname and Schmitz, Nicole and Seboldt, Wolfgang and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and T{\´o}th, Norbert and Vergaaij, Merel and Viavattene, Giulia and Wejmo, Elisabet and Wiedemann, Carsten and Wolff, Friederike and Ziach, Christian},
  title     = {Flights are ten a sail - Re-use and commonality in the design and system engineering of small spacecraft solar sail missions with modular hardware for responsive and adaptive exploration},
  series = {70th International Astronautical Congress (IAC)},
  booktitle = {70th International Astronautical Congress (IAC)},
  isbn      = {9781713814856},
  pages     = {1 -- 7},
  year      = {2019},
  language  = {en}
}