@inproceedings{GrundmannBauerBorchersetal.2019,
  author    = {Grundmann, Jan Thimo and Bauer, Wlademar and Borchers, Kai and Dumont, Etienne and Grimm, Christian D. and Ho, Tra-Mi and Jahnke, Rico and Koch, Aaron D. and Lange, Caroline and Maiwald, Volker and Meß, Jan-Gerd and Mikulz, Eugen and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Sasaki, Kaname and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and Toth, Norbert and Ceriotti, Matteo and McInnes, Colin and Peloni, Alessandro and Biele, Jens and Krause, Christian and Dachwald, Bernd and Hercik, David and Lichtenheldt, Roy and Wolff, Friederike and Koncz, Alexander and Pelivan, Ivanka and Schmitz, Nicole and Boden, Ralf and Riemann, Johannes and Seboldt, Wolfgang and Wejmo, Elisabet and Ziach, Christian and Mikschl, Tobias and Montenegro, Sergio and Ruffer, Michael and Cordero, Federico and Tardivel, Simon},
  title     = {Solar sails for planetary defense \& high-energy missions},
  series = {IEEE Aerospace Conference Proceedings},
  booktitle = {IEEE Aerospace Conference Proceedings},
  doi       = {10.1109/AERO.2019.8741900},
  pages     = {1 -- 21},
  year      = {2019},
  abstract  = {20 years after the successful ground deployment test of a (20 m) 2 solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and hardware design studies as well as the hardware built in the course of our solar sail technology development. We outline the most likely and most efficient routes to develop solar sails for useful missions in science and applications, based on our developed `now-term' and near-term hardware as well as the many practical and managerial lessons learned from the DLR-ESTEC Gossamer Roadmap. Mission types directly applicable to planetary defense include single and Multiple NEA Rendezvous ((M)NR) for precursor, monitoring and follow-up scenarios as well as sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation. Other mission types such as the Displaced L1 (DL1) space weather advance warning and monitoring or Solar Polar Orbiter (SPO) types demonstrate the capability of near-term solar sails to achieve asteroid rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. Some of these mission types such as SPO, (M)NR and RKI include separable payloads. For one-way access to the asteroid surface, nanolanders like MASCOT are an ideal match for solar sails in micro-spacecraft format, i.e. in launch configurations compatible with ESPA and ASAP secondary payload platforms. Larger landers similar to the JAXA-DLR study of a Jupiter Trojan asteroid lander for the OKEANOS mission can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. The high impact velocities and re-try capability achieved by the RKI mission type on a final orbit identical to the target asteroid's but retrograde to its motion enables small spacecraft size impactors to carry sufficient kinetic energy for deflection.},
  language  = {en}
}
@inproceedings{SeboldtDachwald2003,
  author    = {Seboldt, Wolfgang and Dachwald, Bernd},
  title     = {Solar sails for near-term advanced scientific deep space missions},
  series = {Proceedings of the 8th International Workshop on Combustion and Propulsion},
  booktitle = {Proceedings of the 8th International Workshop on Combustion and Propulsion},
  pages     = {14 Seiten},
  year      = {2003},
  abstract  = {Solar sails are propelled in space by reflecting solar photons off large mirroring surfaces, thereby transforming the momentum of the photons into a propulsive force. This innovative concept for low-thrust space propulsion works without any propellant and thus provides a wide range of opportunities for highenergy low-cost missions. Offering an efficient way of propulsion, solar sailcraft could close a gap in transportation options for highly demanding exploration missions within our solar system and even beyond. On December 17th, 1999, a significant step was made towards the realization of this technology: a lightweight solar sail structure with an area of 20 m × 20 m was successfully deployed on ground in a large facility at the German Aerospace Center (DLR) at Cologne. The deployment from a package of 60 cm × 60 cm × 65 cm with a total mass of less than 35 kg was achieved using four extremely light-weight carbon fiber reinforced plastics (CFRP) booms with a specific mass of 100 g/m. The paper briefly reviews the basic principles of solar sails as well as the technical concept and its realization in the ground demonstration experiment, performed in close cooperation between DLR and ESA. Next possible steps are outlined. They could comprise the in-orbit demonstration of the sail deployment on the upper stage of a low-cost rocket and the verification of the propulsion concept by an autonomous and free flying solar sail in the frame of a scientific mission. It is expected that the present design could be extended to sail sizes of about (40 m)2 up to even (70 m)2 without significant mass penalty. With these areas, the maximum achievable thrust at 1 AU would range between 10 and 40 mN - comparable to some electric thrusters. Such prototype sails with a mass between 50 and 150 kg plus a micro-spacecraft of 50 to 250 kg would have a maximum acceleration in the order of 0.1 mm/s2 at 1 AU, corresponding to a maximum ∆V-capability of about 3 km/s per year. Two near/medium-term mission examples to a near-Earth asteroid (NEA) will be discussed: a rendezvous mission and a sample return mission.},
  language  = {en}
}
@article{DachwaldSeboldt2005,
  author    = {Dachwald, Bernd and Seboldt, W.},
  title     = {Solar Sails for Near- and Medium-Term Scientific Deep Space Missions / W. Sebolt ; B. Dachwald},
  series = {In-space propulsion : edited book of proceedings of the 10-IWCP, the 10th International Workshop on Combustion and Propulsion held in Lerici, La Spezia, Italy, 21-25 September 2003 / [ed.: Luigi T. DeLuca]},
  journal   = {In-space propulsion : edited book of proceedings of the 10-IWCP, the 10th International Workshop on Combustion and Propulsion held in Lerici, La Spezia, Italy, 21-25 September 2003 / [ed.: Luigi T. DeLuca]},
  publisher = {SP Lab, Politecnico di Milano},
  address   = {Milano},
  pages     = {getr. Z{\"a}hlung . Ill.},
  year      = {2005},
  language  = {en}
}
@article{DachwaldKahleWie2006,
  author    = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong},
  title     = {Solar Sailing Kinetic Energy Impactor (KEI) Mission Design Tradeoffs for Impacting and Deflecting Asteroid 99942 Apophis},
  series = {AIAA Guidance, Navigation, and Control Conference \& Exhibit - AIAA Atmospheric Flight Mechanics Conference \& Exhibit - AIAA Modeling and Simulation Technologies Conference \& Exhibit - AIAA/AAS Astrodynamics Specialist Conference \& Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )},
  journal   = {AIAA Guidance, Navigation, and Control Conference \& Exhibit - AIAA Atmospheric Flight Mechanics Conference \& Exhibit - AIAA Modeling and Simulation Technologies Conference \& Exhibit - AIAA/AAS Astrodynamics Specialist Conference \& Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )},
  publisher = {American Institute of Aeronautics and Astronautics},
  address   = {Reston, Va.},
  isbn      = {1-56347-802-1},
  pages     = {1 -- 20},
  year      = {2006},
  language  = {en}
}
@article{DachwaldSeboldt2003,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang},
  title     = {Solar sailcraft of the first generation technology development / Seboldt, Wolfgang ; Dachwald, Bernd},
  year      = {2003},
  language  = {en}
}
@article{DachwaldSeboldt2003,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang},
  title     = {Solar sailcraft of the first generation mission applications to near-earth asteroids},
  year      = {2003},
  language  = {en}
}
@article{DachwaldOhndorfWie2006,
  author    = {Dachwald, Bernd and Ohndorf, A. and Wie, Bong},
  title     = {Solar Sail Trajectory Optimization for the Solar Polar Imager (SPI) Mission},
  series = {AIAA Guidance, Navigation, and Control Conference \& Exhibit - AIAA Atmospheric Flight Mechanics Conference \& Exhibit - AIAA Modeling and Simulation Technologies Conference \& Exhibit - AIAA/AAS Astrodynamics Specialist Conference \& Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )},
  journal   = {AIAA Guidance, Navigation, and Control Conference \& Exhibit - AIAA Atmospheric Flight Mechanics Conference \& Exhibit - AIAA Modeling and Simulation Technologies Conference \& Exhibit - AIAA/AAS Astrodynamics Specialist Conference \& Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )},
  publisher = {American Institute of Aeronautics and Astronautics},
  address   = {Reston, Va.},
  isbn      = {1-56347-802-1},
  pages     = {2 CD-ROMs.},
  year      = {2006},
  language  = {en}
}
@article{DachwaldWie2005,
  author    = {Dachwald, Bernd and Wie, Bong},
  title     = {Solar Sail Trajectory Optimization for Intercepting, Impacting, and Deflecting Near-Earth Asteroids},
  series = {AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17)},
  journal   = {AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17)},
  publisher = {American Institute of Aeronautics and Astronautics},
  address   = {Reston, Va.},
  isbn      = {1-56347-765-3},
  pages     = {2 CD-ROMs},
  year      = {2005},
  language  = {en}
}
@article{DachwaldSeboldtLaemmerzahl2008,
  author    = {Dachwald, Bernd and Seboldt, W. and L{\"a}mmerzahl, W.},
  title     = {Solar Sail Propulsion: An Enabling Technology for Fundamental Physics Missions},
  series = {Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansj{\"o}rg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)},
  journal   = {Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansj{\"o}rg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {978-3-540-34376-9},
  pages     = {379 -- 398},
  year      = {2008},
  language  = {en}
}
@inproceedings{Dachwald2004,
  author    = {Dachwald, Bernd},
  title     = {Solar sail performance requirements for missions to the outer solar system and beyond},
  series = {55th International Astronautical Congress 2004},
  booktitle = {55th International Astronautical Congress 2004},
  doi       = {10.2514/6.IAC-04-S.P.11},
  pages     = {1 -- 9},
  year      = {2004},
  abstract  = {Solar sails enable missions to the outer solar system and beyond, although the solar radiation pressure decreases with the square of solar distance. For such missions, the solar sail may gain a large amount of energy by first making one or more close approaches to the sun. Within this paper, optimal trajectories for solar sail missions to the outer planets and into near interstellar space (200 AU) are presented. Thereby, it is shown that even near/medium-term solar sails with relatively moderate performance allow reasonable transfer times to the boundaries of the solar system.},
  language  = {en}
}
@article{DachwaldWi2007,
  author    = {Dachwald, Bernd and Wi, Bong},
  title     = {Solar Sail Kinetic Energy Impactor Trajectory Optimization for an Asteroid-Deflection Mission},
  series = {Journal of Spacecraft and Rockets. 44 (2007), H. 4},
  journal   = {Journal of Spacecraft and Rockets. 44 (2007), H. 4},
  isbn      = {0022-4650},
  pages     = {755 -- 764},
  year      = {2007},
  language  = {en}
}
@inproceedings{DachwaldKahleWie2006,
  author    = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong},
  title     = {Solar sail Kinetic Energy Impactor (KEI) mission design tradeoffs for impacting and deflecting asteroid 99942 Apophis},
  series = {AIAA/AAS Astrodynamics Specialist Conference and Exhibit},
  booktitle = {AIAA/AAS Astrodynamics Specialist Conference and Exhibit},
  doi       = {10.2514/6.2006-6178},
  pages     = {1 -- 20},
  year      = {2006},
  abstract  = {Near-Earth asteroid 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 so-called gravitational keyholes during its 2029-encounter. Several pre-2029-deflection scenarios to prevent Apophis from doing this have been investigated so far. Because the keyholes are less than 1 km in size, a pre-2029 kinetic impact is clearly the best option because it requires only a small change in Apophis' orbit to nudge it out of a keyhole. A single solar sail Kinetic Energy Impactor (KEI) spacecraft that impacts Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages at about 0.75 AU would be a feasible option to do this. The spacecraft consists of a 160 m x 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. In this paper, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, solar sail Kinetic Energy Impactor (KEI) spacecraft are still a feasible option 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. In this paper, we elaborate potential pre- and post-2029 KEI impact scenarios for a launch in 2020, and investigate tradeoffs between different mission parameters.},
  language  = {en}
}
@incollection{Dachwald2010,
  author    = {Dachwald, Bernd},
  title     = {Solar sail dynamics and control},
  series = {Encyclopedia of Aerospace Engineering},
  booktitle = {Encyclopedia of Aerospace Engineering},
  publisher = {Wiley},
  address   = {Hoboken},
  doi       = {10.1002/9780470686652.eae292},
  year      = {2010},
  abstract  = {Solar sails are large and lightweight reflective structures that are propelled by solar radiation pressure. This chapter covers their orbital and attitude dynamics and control. First, the advantages and limitations of solar sails are discussed and their history and development status is outlined. Because the dynamics of solar sails is governed by the (thermo-)optical properties of the sail film, the basic solar radiation pressure force models have to be described and compared before parameters to measure solar sail performance can be defined. The next part covers the orbital dynamics of solar sails for heliocentric motion, planetocentric motion, and motion at Lagrangian equilibrium points. Afterwards, some advanced solar radiation pressure force models are described, which allow to quantify the thrust force on solar sails of arbitrary shape, the effects of temperature, of light incidence angle, of surface roughness, and the effects of optical degradation of the sail film in the space environment. The orbital motion of a solar sail is strongly coupled to its rotational motion, so that the attitude control of these soft and flexible structures is very challenging, especially for planetocentric orbits that require fast attitude maneuvers. Finally, some potential attitude control methods are sketched and selection criteria are given.},
  language  = {en}
}
@inproceedings{GrundmannBodenCeriottietal.2017,
  author    = {Grundmann, Jan Thimo and Boden, Ralf and Ceriotti, Matteo and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Lange, Caroline and Lichtenheldt, Roy and Pelivan, Ivanka and Peloni, Alessandro and Riemann, Johannes and Spr{\"o}witz, Tom and Tardivel, Simon},
  title     = {Soil to sail-asteroid landers on near-term sailcraft as an evolution of the GOSSAMER small spacecraft solar sail concept for in-situ characterization},
  series = {5th IAA Planetary Defense Conference},
  booktitle = {5th IAA Planetary Defense Conference},
  pages     = {30 Seiten},
  year      = {2017},
  language  = {en}
}
@inproceedings{GrundmannBauerBorchersetal.2018,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Borchers, Kai and Dumont, Etienne and Grimm, Christian D. and Ho, Tra-Mi and Jahnke, Rico and Lange, Caroline and Maiwald, Volker and Mikulz, Eugen and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Riemann, Johannes and Sasaki, Kaname and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Toth, Norbert and Wejmo, Elisabet and Biele, Jens and Krause, Christian and Cerotti, Matteo and Peloni, Alessandro and Dachwald, Bernd},
  title     = {Small Spacecraft Solar Sailing for Small Solar System Body Multiple Rendezvous and Landing},
  series = {2018 IEEE Aerospace Conference : 3-10 March 2018},
  booktitle = {2018 IEEE Aerospace Conference : 3-10 March 2018},
  isbn      = {978-1-5386-2014-4},
  pages     = {20 Seiten},
  year      = {2018},
  language  = {en}
}
@inproceedings{GrundmannMessBieleetal.2017,
  author    = {Grundmann, Jan Thimo and Meß, Jan-Gerd and Biele, Jens and Seefeldt, Patric and Dachwald, Bernd and Spietz, Peter and Grimm, Christian D. and Spr{\"o}witz, Tom and Lange, Caroline and Ulamec, Stephan},
  title     = {Small spacecraft in small solar system body applications},
  series = {IEEE Aerospace Conference 2017, Big Sky, Montana, USA},
  booktitle = {IEEE Aerospace Conference 2017, Big Sky, Montana, USA},
  organization    = {IEEE Aerospace Conference},
  isbn      = {978-1-5090-1613-6},
  doi       = {10.1109/AERO.2017.7943626},
  pages     = {1 -- 20},
  year      = {2017},
  language  = {en}
}
@inproceedings{GrundmannLangeDachwaldetal.2015,
  author    = {Grundmann, Jan Thimo and Lange, Caroline and Dachwald, Bernd and Grimm, Christian and Koch, Aaron and Ulamec, Stephan},
  title     = {Small Spacecraft in Planetary Defence Related Applications-Capabilities, Constraints, Challenges},
  series = {IEEE Aerospace Conference},
  booktitle = {IEEE Aerospace Conference},
  pages     = {1 -- 18},
  year      = {2015},
  abstract  = {In this paper we present an overview of the characteristics and peculiarities of small spacecraft missions related to planetary defence applications. We provide a brief overview of small spacecraft missions to small solar system bodies. On this background we present recent missions and selected projects and related studies at the German Aerospace Center, DLR, that contribute to planetary defence related activities. These range from Earth orbit technology demonstrators to active science missions in interplanetary space. We provide a summary of experience from recently flown missions with DLR participation as well as a number of studies. These include PHILAE, the lander recently arrived on comet 67P/Churyumov-Gerasimenko aboard ESA's ROSETTA comet rendezvous mission, and the Mobile Asteroid Surface Scout, MASCOT, now underway to near-Earth asteroid (162173) 1999 JU3 aboard the Japanese sample-return probe HAYABUSA-2. We introduce the differences between the conventional methods employed in the design, integration and testing of large spacecraft and the new approaches developed by small spacecraft projects. We expect that the practical experience that can be gained from projects on extremely compressed timelines or with high-intensity operation phases on a newly explored small solar system body can contribute significantly to the study, preparation and realization of future planetary defence related missions. One is AIDA (Asteroid Impact \& Deflection Assessment), a joint effort of ESA,JHU/APL, NASA, OCA and DLR, combining JHU/APL's DART (Double Asteroid Redirection Test) and ESA's AIM (Asteroid Impact Monitor) spacecraft in a mission towards near-Eath binary asteroid (65803) Didymos.},
  language  = {en}
}
@inproceedings{GrundmannBieleDachwaldetal.2016,
  author    = {Grundmann, Jan Thimo and Biele, Jens and Dachwald, Bernd and Grimm, Christian and Lange, Caroline and Ulamec, Stephan},
  title     = {Small spacecraft for small solar system body science, planetary defence and applications},
  series = {IEEE Aerospace Conference 2016},
  booktitle = {IEEE Aerospace Conference 2016},
  pages     = {1 -- 20},
  year      = {2016},
  abstract  = {Following the recent successful landings and occasional re-awakenings of PHILAE, the lander carried aboard ROSETTA to comet 67P/Churyumov-Gerasimenko, and the launch of the Mobile Asteroid Surface Scout, MASCOT, aboard the HAYABUSA2 space probe to asteroid (162173) Ryugu we present an overview of the characteristics and peculiarities of small spacecraft missions to small solar system bodies (SSSB). Their main purpose is planetary science which is transitioning from a 'pure' science of observation of the distant to one also supporting in-situ applications relevant for life on Earth. Here we focus on missions at the interface of SSSB science and planetary defence applications. We provide a brief overview of small spacecraft SSSB missions and on this background present recent missions, projects and related studies at the German Aerospace Center, DLR, that contribute to the worldwide planetary defence community. These range from Earth orbit technology demonstrators to active science missions in interplanetary space. We provide a summary of experience from recently flown missions with DLR participation as well as a number of studies. These include PHILAE, the lander of ESA's ROSETTA comet rendezvous mission now on the surface of comet 67P/Churyumov-Gerasimenko, and the Mobile Asteroid Surface Scout, MASCOT, now in cruise to the ~1 km diameter C-type near-Earth asteroid (162173) Ryugu aboard the Japanese sample-return probe HAYABUSA2. We introduce the differences between the conventional methods employed in the design, integration and testing of large spacecraft and the new approaches developed by small spacecraft projects. We expect that the practical experience that can be gained from projects on extremely compressed timelines or with high-intensity operation phases on a newly explored small solar system body can contribute significantly to the study, preparation and realization of future planetary defence related missions. One is AIDA (Asteroid Impact \& Deflection Assessment), a joint effort of ESA, JHU/APL, NASA, OCA and DLR, combining JHU/APL's DART (Double Asteroid Redirection Test) and ESA's AIM (Asteroid Impact Monitor) spacecraft in a mission towards near-Earth binary asteroid system (65803) Didymos. DLR is currently applying MASCOT heritage and lessons learned to the design of MASCOT2, a lander for the AIM mission to support a bistatic low frequency radar experiment with PHILAE/ROSETTA CONSERT heritage to explore the inner structure of Didymoon which is the designated impact target for DART.},
  language  = {en}
}
@inproceedings{GrundmannBauerBieleetal.2018,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Biele, Jens and Boden, Ralf and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Herč{\´i}k, David and Ho, Tra-Mi and Jahnke, Rico and Koch, Aaron D and Koncz, Alexander and Krause, Christian and Lange, Caroline and Lichtenheldt, Roy and Maiwald, Volker and Mikschl, Tobias and Mikulz, Eugen and Montenegro, Sergio and Pelivan, Ivanka and Peloni, Alessandro and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Riemann, Johannes 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 Tardivel, Simon and T{\´o}th, Norbert and Wejmo, Elisabet and Wolff, Friederike and Ziach, Christian},
  title     = {Small spacecraft based multiple near-earth asteroid rendezvous and landing with near-term solar sails and 'Now-Term 'technologies},
  series = {69 th International Astronautical Congress (IAC)},
  booktitle = {69 th International Astronautical Congress (IAC)},
  pages     = {1 -- 18},
  year      = {2018},
  abstract  = {Physical interaction with small solar system bodies (SSSB) is the next step in planetary science, planetary in-situ resource utilization (ISRU), and planetary defense (PD). It requires a broader understanding of the surface properties of the target objects, with particular interest focused on those near Earth. Knowledge of composition, multi-scale surface structure, thermal response, and interior structure is required to design, validate and operate missions addressing these three fields. The current level of understanding is occasionally simplified into the phrase, "If you've seen one asteroid, you've seen one asteroid", meaning that the in-situ characterization of SSSBs has yet to cross the threshold towards a robust and stable scheme of classification. This would enable generic features in spacecraft design, particularly for ISRU and science missions. Currently, it is necessary to characterize any potential target object sufficiently by a dedicated pre-cursor mission to design the mission which then interacts with the object in a complex fashion. To open up strategic approaches, much broader in-depth characterization of potential target objects would be highly desirable. In SSSB science missions, MASCOT-like nano-landers and instrument carriers which integrate at the instrument level to their mothership have met interest. By its size, MASCOT is compatible with small interplanetary missions. The DLR-ESTEC Gossamer Roadmap Science Working Groups' studies identified Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the space science missions only feasible with solar sail propulsion. The Solar Polar Orbiter (SPO) study showed the ability to access any inclination, theDisplaced-L1 (DL1) mission operates close to Earth, where objects of interest to PD and for ISRU reside. Other studies outline the unique capability of solar sails to provide access to all SSSB, at least within the orbit of Jupiter, and significant progress has been made to explore the performance envelope of near-term solar sails for MNR. However, it is difficult for sailcraft to interact physically with a SSSB. We expand and extend the philosophy of the recently qualified DLR Gossamer solar sail deployment technology using efficient multiple sub-spacecraft integration to also include landers for one-way in-situ investigations and sample-return missions by synergetic integration and operation of sail and lander. The MASCOT design concept and its characteristic features have created an ideal counterpart for thisand has already been adapted to the needs of the AIM spacecraft, former part of the NASA-ESA AIDA missionDesigning the 69th International Astronautical Congress (IAC), Bremen, Germany, 1-5 October 2018. IAC-18-F1.2.3 Page 2 of 17 combined spacecraft for piggy-back launch accommodation enables low-cost massively parallel access to the NEA population.},
  language  = {en}
}
@inproceedings{GrundmannBieleDachwaldetal.2017,
  author    = {Grundmann, Jan Thimo and Biele, Jens and Dachwald, Bernd and Grimm, Christian D. and Lange, Caroline and Ulamec, Stephan and Ziach, Christian and Spr{\"o}witz, Tom and Ruffer, Michael and Seefeldt, Patric and Spietz, Peter and Toth, Norbert and Mimasu, Yuya and Rittweger, Andreas and Bibring, Jean-Pierre and Braukhane, Andy and Boden, Ralf Christian and Dumont, Etienne and Jahnke, Stephan Siegfried and Jetzschmann, Michael and Kr{\"u}ger, Hans and Lange, Michael and Gomez, Antonio Martelo and Massonett, Didier and Okada, Tatsuaki and Sagliano, Marco and Sasaki, Kaname and Schr{\"o}der, Silvio and Sippel, Martin and Skoczylas, Thomas and Wejmo, Elisabet},
  title     = {Small landers and separable sub-spacecraft for near-term solar sails},
  series = {The Fourth International Symposium on Solar Sailing 2017},
  booktitle = {The Fourth International Symposium on Solar Sailing 2017},
  pages     = {1 -- 10},
  year      = {2017},
  abstract  = {Following the successful PHILAE landing with ESA's ROSETTA probe and the launch of the MINERVA rovers and the Mobile Asteroid Surface Scout, MASCOT, aboard the JAXA space probe, HAYABUSA2, to asteroid (162173) Ryugu, small landers have found increasing interest. Integrated at the instrument level in their mothership they support small solar system body studies. With efficient capabilities, resource-friendly design and inherent robustness they are an attractive exploration mission element. We discuss advantages and constraints of small sub-spacecraft, focusing on emerging areas of activity such as asteroid diversity studies, planetary defence, and asteroid mining, on the background of our projects PHILAE, MASCOT, MASCOT2, the JAXA-DLR Solar Power Sail Lander Design Study, and others. The GOSSAMER-1 solar sail deployment concept also involves independent separable sub-spacecraft operating synchronized to deploy the sail. Small spacecraft require big changes in the way we do things and occasionally a little more effort than would be anticipated based on a traditional large spacecraft approach. In a Constraints-Driven Engineering environment we apply Concurrent Design and Engineering (CD/CE), Concurrent Assembly, Integration and Verification (CAIV) and Model-Based Systems Engineering (MBSE). Near-term solar sails will likely be small spacecraft which we expect to harmonize well with nano-scale separable instrument payload packages.},
  language  = {en}
}
@inproceedings{LoebSchartnerDachwaldetal.2007,
  author    = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Seboldt, Wolfgang},
  title     = {SEP-Sample return from a main belt asteroid},
  series = {30th International Electric Propulsion Conference},
  booktitle = {30th International Electric Propulsion Conference},
  pages     = {1 -- 11},
  year      = {2007},
  abstract  = {By DLR-contact, sample return missions to the large main-belt asteroid "19, Fortuna" have been studied. The mission scenario has been based on three ion thrusters of the RIT-22 model, which is presently under space qualification, and on solar arrays equipped with triple-junction GaAs solar cells. After having designed the spacecraft, the orbit-to-orbit trajectories for both, a one-way SEP mission with a chemical sample return and an all-SEP return mission, have been optimized using a combination of artificial neural networks with evolutionary algorithms. Additionally, body-to-body trajectories have been investigated within a launch period between 2012 and 2015. For orbit-to-orbit calculation, the launch masses of the hybrid mission and of the all-SEP mission resulted in 2.05 tons and 1.56 tons, respectively, including a scientific payload of 246 kg. For the related transfer durations 4.14 yrs and 4.62 yrs were obtained. Finally, a comparison between the mission scenarios based on SEP and on NEP have been carried out favouring clearly SEP.},
  language  = {en}
}
@inproceedings{LoebSchartnerSeboldtetal.2006,
  author    = {Loeb, Horst W. and Schartner, Karl-Heinz and Seboldt, Wolfgang and Dachwald, Bernd and Streppel, Joern and Meusemann, Hans and Sch{\"u}lke, Peter},
  title     = {SEP for a lander mission to the jovian moon europa},
  series = {57th International Astronautical Congress},
  booktitle = {57th International Astronautical Congress},
  doi       = {10.2514/6.IAC-06-C4.4.04},
  pages     = {1 -- 12},
  year      = {2006},
  abstract  = {Under DLR-contract, Giessen University and DLR Cologne are studying solar-electric propulsion missions (SEP) to the outer regions of the solar system. The most challenging reference mission concerns the transport of a 1.35-tons chemical lander spacecraft into an 80-RJ circular orbit around Jupiter, which would enable to place a 375 kg lander with 50 kg of scientific instruments on the surface of the icy moon "Europa". Thorough analyses show that the best solution in terms of SEP launch mass times thrusting time would be a two-stage EP module and a triple-junction solar array with concentrators which would be deployed step by step. Mission performance optimizations suggest to propel the spacecraft in the first EP stage by 6 gridded ion thrusters, running at 4.0 kV of beam voltage, which would save launch mass, and in the second stage by 4 thrusters with 1.25 to 1.5 kV of positive high voltage saving thrusting time. In this way, the launch mass of the spacecraft would be kept within 5.3 tons. Without a launcher's C3 and interplanetary gravity assists, Jupiter might be reached within about 4 yrs. The spiraling-down into the parking orbit would need another 1.8 yrs. This "large mission" can be scaled down to a smaller one, e.g., by halving all masses, the solar array power, and the number of thrusters. Due to their reliability, long lifetime and easy control, RIT-22 engines have been chosen for mission analysis. Based on precise tests, the thruster performance has been modeled.},
  language  = {en}
}
@inproceedings{WaldmannVeraDachwaldetal.2018,
  author    = {Waldmann, Christoph and Vera, Jean-Pierre de and Dachwald, Bernd and Strasdeit, Henry and Sohl, Frank and Hanff, Hendrik and Kowalski, Julia and Heinen, Dirk and Macht, Sabine and Bestmann, Ulf and Meckel, Sebastian and Hildebrandt, Marc and Funke, Oliver and Gehrt, Jan-J{\"o}ran},
  title     = {Search for life in ice-covered oceans and lakes beyond Earth},
  series = {2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761},
  booktitle = {2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761},
  doi       = {10.1109/AUV.2018.8729761},
  year      = {2018},
  abstract  = {The quest for life on other planets is closely connected with the search for water in liquid state. Recent discoveries of deep oceans on icy moons like Europa and Enceladus have spurred an intensive discussion about how these waters can be accessed. The challenge of this endeavor lies in the unforeseeable requirements on instrumental characteristics both with respect to the scientific and technical methods. The TRIPLE/nanoAUV initiative is aiming at developing a mission concept for exploring exo-oceans and demonstrating the achievements in an earth-analogue context, exploring the ocean under the ice shield of Antarctica and lakes like Dome-C on the Antarctic continent.},
  language  = {en}
}
@inproceedings{GrundmannBauerBodenetal.2019,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Boden, Ralf Christian and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Hercik, D. and Herique, A. and Ho, Tra-Mi and Jahnke, Rico and Kofman, Wlodek and Lange, Caroline and Lichtenheldt, Roy and McInnes, Colin R. 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 Toth, Norbert and Viavattene, Giulia and Wejmo, Elisabet and Wolff, Friederike and Ziach, Christian},
  title     = {Responsive integrated small spacecraft solar sail and payload design concepts and missions},
  series = {Conference: 5th International Symposium on Solar Sailing (ISSS 2019)},
  booktitle = {Conference: 5th International Symposium on Solar Sailing (ISSS 2019)},
  year      = {2019},
  abstract  = {Asteroid mining has the potential to greatly reduce the cost of in-space manufacturing, production of propellant for space transportation and consumables for crewed spacecraft, compared to launching the required resources from Earth's deep gravity well. This paper discusses the top-level mission architecture and trajectory design for these resource-return missions, comparing high-thrust trajectories with continuous low-thrust solar-sail trajectories. This work focuses on maximizing the economic Net Present Value, which takes the time-cost of finance into account and therefore balances the returned resource mass and mission duration. The different propulsion methods will then be compared in terms of maximum economic return, sets of attainable target asteroids, and mission flexibility. This paper provides one more step towards making commercial asteroid mining an economically viable reality by integrating trajectory design, propulsion technology and economic modelling.},
  language  = {en}
}
@inproceedings{GrundmannBauerBodenetal.2019,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Boden, Ralf Christian and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Hercik, D. and Herique, A. and Ho, Tra-Mi and Jahnke, Rico and Kofman, Wlodek and Lange, Caroline and Lichtenheldt, Roy and McInnes, Colin R. and Mikschl, Tobias and Montenegro, Sergio and Moore, Iain and Pelivan, Ivanka and Peloni, Alessandro and Plettenmeier, 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 Toth, Norbert and Viavattene, Giulia and Wejmo, Elisabet and Wolff, Friederike and Ziach, Christian},
  title     = {Responsive exploration and asteroid characterization through integrated solar sail and lander development using small spacecraft technologies},
  series = {IAA Planetary Defense Conference},
  booktitle = {IAA Planetary Defense Conference},
  year      = {2019},
  abstract  = {In parallel to the evolution of the Planetary Defense Conference, the exploration of small solar system bodies has advanced from fast fly-bys on the sidelines of missions to the planets to the implementation of dedicated sample-return and in-situ analysis missions. Spacecraft of all sizes have landed, touch-and-go sampled, been gently beached, or impacted at hypervelocity on asteroid and comet surfaces. More have flown by close enough to image their surfaces in detail or sample their immediate environment, often as part of an extended or re-purposed mission. And finally, full-scale planetary defense experiment missions are in the making. Highly efficient low-thrust propulsion is increasingly applied beyond commercial use also in mainstream and flagship science missions, in combination with gravity assist propulsion. Another development in the same years is the growth of small spacecraft solutions, not in size but in numbers and individual capabilities. The on-going NASA OSIRIS-REx and JAXA HAYABUSA2 missions exemplify the trend as well as the upcoming NEA SCOUT mission or the landers MINERVA-II and MASCOT recently deployed on Ryugu. We outline likely as well as possible and efficient routes of continuation of all these developments towards a propellant-less and highly efficient class of spacecraft for small solar system body exploration: small spacecraft solar sails designed for carefree handling and equipped with carried landers and application modules, for all asteroid user communities -planetary science, planetary defence, and in-situ resource utilization. This projection builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m)² solar sail at DLR Cologne and in the 20 years since. It draws on the background of extensive trajectory optimization studies, the qualified technology of the DLR GOSSAMER-1 deployment demonstrator, and the MASCOT asteroid lander. These enable 'now-term' as well as near-term hardware solutions, and thus responsive fast-paced development. Mission types directly applicable to planetary defense include: single and Multiple NEA Rendezvous ((M)NR) for mitigation precursor, target monitoring and deflection follow-up tasks; sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation; and deployable membrane based methods to modify the asteroid's properties or interact with it. The DLR-ESTEC GOSSAMER Roadmap initiated studies of missions uniquely feasible with solar sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter (SPO) delivery which demonstrate the capability of near-term solar sails to achieve NEA rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. For those mission types using separable payloads, such as SPO, (M)NR and RKI, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. These are an ideal match for solar sails in micro-spacecraft format whose launch configurations are compatible with ESPA and ASAP secondary payload platforms.},
  language  = {en}
}
@article{DachwaldMengaliQuartaetal.2007,
  author    = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandro A. and Circi, Christian},
  title     = {Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ; Bernd Dachwald},
  series = {Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2},
  journal   = {Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2},
  isbn      = {0162-3192},
  pages     = {512 -- 520},
  year      = {2007},
  language  = {en}
}
@inproceedings{Dachwald2017,
  author    = {Dachwald, Bernd},
  title     = {Radiation pressure force model for an ideal laser-enhanced solar sail},
  series = {4th International Symposium on Solar Sailing},
  booktitle = {4th International Symposium on Solar Sailing},
  pages     = {1 -- 5},
  year      = {2017},
  abstract  = {The concept of a laser-enhanced solar sail is introduced and the radiation pressure force model for an ideal laser-enhanced solar sail is derived. A laser-enhanced solar sail is a "traditional" solar sail that is, however, not solely propelled by solar radiation, but additionally by a laser beam that illuminates the sail. The additional laser radiation pressure increases the sail's propulsive force and can give, depending on the location of the laser source, more control authority over the direction of the solar sail's propulsive force vector. This way, laser-enhanced solar sails may augment already existing solar sail mission concepts and make novel mission concepts feasible.},
  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}
}
@inproceedings{SeboldtBlomeDachwaldetal.2004,
  author    = {Seboldt, Wolfgang and Blome, Hans-Joachim and Dachwald, Bernd and Richter, Lutz},
  title     = {Proposal for an integrated European space exploration strategy},
  series = {55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law},
  booktitle = {55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law},
  pages     = {1 -- 10},
  year      = {2004},
  abstract  = {Recently, in his vision for space exploration, US president Bush announced to extend human presence across the solar system, starting with a human return to the Moon as early as 2015 in preparation for human exploration of Mars and other destinations. In Europe, an exploration program, termed AURORA, was established by ESA in 2001 - funded on a voluntary basis by ESA member states - with a clear focus on Mars and the ultimate goal of landing humans on Mars around 2030 in international cooperation. In 2003, a Human Spaceflight Vision Group was appointed by ESA with the task to develop a vision for the role of human spaceflight during the next quarter of the century. The resulting vision focused on a European-led lunar exploration initiative as part of a multi-decade, international effort to strengthen European identity and economy. After a review of the situation in Europe concerning space exploration, the paper outlines an approach for a consistent positioning of exploration within the existing European space programs, identifies destinations, and develops corresponding scenarios for an integrated strategy, starting with robotic missions to the Moon, Mars, and near-Earth asteroids. The interests of the European planetary in-situ science community, which recently met at DLR Cologne, are considered. Potential robotic lunar missions comprise polar landings to search for frozen volatiles and a sample return. For Mars, the implementation of a modest robotic landing mission in 2009 to demonstrate the capability for landing and prepare more ambitious and complex missions is discussed. For near-Earth asteroid exploration, a low-cost in-situ technology demonstration mission could yield important results. All proposed scenarios offer excellent science and could therefore create synergies between ESA's mandatory and optional programs in the area of planetary science and exploration. The paper intents to stimulate the European discussion on space exploration and reflects the personal view of the authors.},
  language  = {en}
}
@inproceedings{PeloniCeriottiDachwald2015,
  author    = {Peloni, A. and Ceriotti, M. and Dachwald, Bernd},
  title     = {Preliminary trajectory design of a multiple NEO rendezvous mission through solar sailing},
  series = {Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014},
  booktitle = {Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014},
  publisher = {Curran},
  address   = {Red Hook, NY},
  isbn      = {978-1-63439-986-9},
  pages     = {5352 -- 5366},
  year      = {2015},
  language  = {en}
}
@article{KezerashviliDachwald2021,
  author    = {Kezerashvili, Roman Ya and Dachwald, Bernd},
  title     = {Preface: Solar sailing: Concepts, technology, and missions II},
  series = {Advances in Space Research},
  volume    = {67},
  journal   = {Advances in Space Research},
  number    = {9},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2021.01.037},
  pages     = {2559 -- 2560},
  year      = {2021},
  language  = {en}
}
@article{DachwaldSeboldtMacdonaldetal.2005,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang and Macdonald, Malcolm and Mengali, Giovanni and Quatra, Alessandro A. and McInnes, Colin R. and Rios-Reyes, Leonel and Scheerers, Daniel J. and Wie, Bong and G{\"o}rlich, Marianne and Lura, Franz and Diedrich, Benjamin and Baturkin, Volodymyr and Coverstone, Victoria L. and Leipold, Manfred and Garbe, Gregory P.},
  title     = {Potential Solar Sail Degradation Effects on Trajectory and Attitude Control},
  series = {AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17)},
  journal   = {AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17)},
  publisher = {American Institute of Aeronautics and Astronautics},
  address   = {Reston, Va.},
  isbn      = {1-56347-765-3},
  pages     = {2 CD-ROMs},
  year      = {2005},
  language  = {en}
}
@inproceedings{DachwaldBaturkinCoverstoneetal.2005,
  author    = {Dachwald, Bernd and Baturkin, Volodymyr and Coverstone, Victoria and Diedrich, Ben and Garbe, Gregory and G{\"o}rlich, Marianne and Leipold, Manfred and Lura, Franz and Macdonald, Malcolm and McInnes, Colin and Mengali, Giovanni and Quarta, Alessandro and Rios-Reyes, Leonel and Scheeres, Daniel J. and Seboldt, Wolfgang and Wie, Bong},
  title     = {Potential effects of optical solar sail degredation on trajectory design},
  series = {AAS/AIAA Astrodynamics Specialist},
  booktitle = {AAS/AIAA Astrodynamics Specialist},
  pages     = {1 -- 23},
  year      = {2005},
  abstract  = {The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions.},
  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{HeiligersSchoutetensDachwald2021,
  author    = {Heiligers, Jeannette and Schoutetens, Frederic and Dachwald, Bernd},
  title     = {Photon-sail equilibria in the alpha centauri system},
  series = {Journal of Guidance, Control, and Dynamics},
  volume    = {44},
  journal   = {Journal of Guidance, Control, and Dynamics},
  number    = {5},
  issn      = {1533-3884},
  doi       = {10.2514/1.G005446},
  pages     = {1053 -- 1061},
  year      = {2021},
  language  = {en}
}
@inproceedings{SchartnerLoebDachwaldetal.2009,
  author    = {Schartner, Karl-Heinz and Loeb, H. W. and Dachwald, Bernd and Ohndorf, Andreas},
  title     = {Perspectives of electric propulsion for outer planetary and deep space missions},
  series = {European Planetary Science Congress 2009},
  booktitle = {European Planetary Science Congress 2009},
  pages     = {416 -- 416},
  year      = {2009},
  abstract  = {Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low-thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3].},
  language  = {en}
}
@inproceedings{DachwaldSeboldtHaeusler2002,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang and H{\"a}usler, Bernd},
  title     = {Performance requirements for near-term interplanetary solar sailcraft missions},
  series = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century},
  booktitle = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century},
  pages     = {9 Seiten},
  year      = {2002},
  abstract  = {Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation. However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions.},
  language  = {en}
}
@article{ScholzRomagnoliDachwaldetal.2011,
  author    = {Scholz, Christina and Romagnoli, Daniele and Dachwald, Bernd and Theil, Stephan},
  title     = {Performance analysis of an attitude control system for solar sails using sliding masses},
  series = {Advances in Space Research},
  volume    = {48},
  journal   = {Advances in Space Research},
  number    = {11},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  pages     = {1822 -- 1835},
  year      = {2011},
  language  = {en}
}
@article{SpietzSproewitzSeefeldtetal.2021,
  author    = {Spietz, Peter and Spr{\"o}witz, Tom and Seefeldt, Patric and Grundmann, Jan Thimo and Jahnke, Rico and Mikschl, Tobias and Mikulz, Eugen and Montenegro, Sergio and Reershemius, Siebo and Renger, Thomas and Ruffer, Michael and Sasaki, Kaname and Sznajder, Maciej and T{\´o}th, Norbert and Ceriotti, Matteo and Dachwald, Bernd and Macdonald, Malcolm and McInnes, Colin and Seboldt, Wolfgang and Quantius, Dominik and Bauer, Waldemar and Wiedemann, Carsten and Grimm, Christian D. and Hercik, David and Ho, Tra-Mi and Lange, Caroline and Schmitz, Nicole},
  title     = {Paths not taken - The Gossamer roadmap's other options},
  series = {Advances in Space Research},
  volume    = {67},
  journal   = {Advances in Space Research},
  number    = {9},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2021.01.044},
  pages     = {2912 -- 2956},
  year      = {2021},
  language  = {en}
}
@article{DachwaldMengaliQuartaetal.2006,
  author    = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandrao A. and Macdonald, Malcolm},
  title     = {Parametric Model and Optimal Control of Solar Sails with Optical Degradation},
  series = {Journal of guidance, control, and dynamics. 29 (2006), H. 5},
  journal   = {Journal of guidance, control, and dynamics. 29 (2006), H. 5},
  isbn      = {0162-3192},
  pages     = {1170 -- 1178},
  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{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{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{DachwaldOhndorfGill2009,
  author    = {Dachwald, Bernd and Ohndorf, A. and Gill, E.},
  title     = {Optimization of low-thrust Earth-Moon transfers using evolutionary neurocontrol / Ohndorf, A. ; Dachwald, B. ; Gill, E.},
  series = {IEEE Congress on Evolutionary Computation, 2009. CEC '09.},
  journal   = {IEEE Congress on Evolutionary Computation, 2009. CEC '09.},
  isbn      = {978-1-4244-2958-5},
  pages     = {358 -- 364},
  year      = {2009},
  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{DachwaldSeboldt2002,
  author    = {Dachwald, Bernd and Seboldt, W.},
  title     = {Optimization of Interplanetary Rendezvous Trajectories for Solar Sailcraft Using a Neurocontroller},
  series = {A collection of technical papers / AIAA Astrodynamics Specialist Conference : Monterey, California, 5 - 8 August 2002. - Vol. 2},
  journal   = {A collection of technical papers / AIAA Astrodynamics Specialist Conference : Monterey, California, 5 - 8 August 2002. - Vol. 2},
  publisher = {American Institute of Aeronautics and Astronautics},
  address   = {Reston, Va.},
  isbn      = {1-56347-549-9},
  pages     = {1263 -- 1270},
  year      = {2002},
  language  = {en}
}
@inproceedings{SchoutetensDachwaldHeiligers2021,
  author    = {Schoutetens, Frederic and Dachwald, Bernd and Heiligers, Jeannette},
  title     = {Optimisation of photon-sail trajectories in the alpha-centauri system using evolutionary neurocontrol},
  series = {8th ICATT (International Conference on Astrodynamics Tools and Techniques) 23 - 25 June 2021, Virtual},
  booktitle = {8th ICATT (International Conference on Astrodynamics Tools and Techniques) 23 - 25 June 2021, Virtual},
  pages     = {1 -- 15},
  year      = {2021},
  abstract  = {With the increased interest for interstellar exploration after the discovery of exoplanets and the proposal by Breakthrough Starshot, this paper investigates the optimisation of photon-sail trajectories in Alpha Centauri. The prime objective is to find the optimal steering strategy for a photonic sail to get captured around one of the stars after a minimum-time transfer from Earth. By extending the idea of the Breakthrough Starshot project with a deceleration phase upon arrival, the mission's scientific yield will be increased. As a secondary objective, transfer trajectories between the stars and orbit-raising manoeuvres to explore the habitable zones of the stars are investigated. All trajectories are optimised for minimum time of flight using the trajectory optimisation software InTrance. Depending on the sail technology, interstellar travel times of 77.6-18,790 years can be achieved, which presents an average improvement of 30\% with respect to previous work. Still, significant technological development is required to reach and be captured in the Alpha-Centauri system in less than a century. Therefore, a fly-through mission arguably remains the only option for a first exploratory mission to Alpha Centauri, but the enticing results obtained in this work provide perspective for future long-residence missions to our closest neighbouring star system.},
  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     = {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}
}
@inproceedings{DachwaldMengaliQuartaetal.2007,
  author    = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandro A and Macdonald, Malcolm and McInnes, Colin R},
  title     = {Optical solar sail degradation modelling},
  series = {1st International Symposium on Solar Sailing},
  booktitle = {1st International Symposium on Solar Sailing},
  pages     = {1 -- 27},
  year      = {2007},
  abstract  = {We propose a simple parametric OSSD model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails.},
  language  = {en}
}