TY  - CHAP
A1  - Kemper, Hans
A1  - Hellenbroich, Gereon
A1  - Esch, Thomas
T1  - Concept of an innovative passenger-car hybrid drive for European driving conditions
T2  - Hybrid vehicles and energy management : 6th symposium ; 18th and 19th February 2009, Stadthalle Braunschweig
N2  - The downsizing of spark ignition engines in conjunction with turbocharging is considered to be a promising method for reducing CO₂ emissions. Using this concept, FEV has developed a new, highly efficient drivetrain to demonstrate fuel consumption reduction and drivability in a vehicle based on the Ford Focus ST. The newly designed 1.8L turbocharged gasoline engine incorporates infinitely variable intake and outlet control timing and direct fuel injection utilizing piezo injectors centrally located. In addition, this engine uses a prototype FEV engine control system, with software that was developed and adapted entirely by FEV. The vehicle features a 160 kW engine with a maximum mean effective pressure of 22.4 bar and 34 % savings in simulated fuel consumption. During the first stage, a new electrohydraulically actuated hybrid transmission with seven forward gears and one reverse gear and a single dry starting clutch will be integrated. The electric motor of the hybrid is directly connected to the gear set of the transmission. Utilizing the special gear set layout, the electric motor can provide boost during a change of gears, so that there is no interruption in traction. Therefore, the transmission system combines the advantages of a double clutch controlled gear change (gear change without an interruption in traction) with the efficient, cost-effective design of an automated manual transmission system. Additionally, the transmission provides a purely electric drive system and the operation of an air-conditioning compressor during the engine stop phases. One other alternative is through the use of CAI (Controlled Auto Ignition), which incorporates a process developed by FEV for controlled compression ignition.
Y1  - 2009
SN  - 978-3-937655-20-8
SP  - 264
EP  - 287
PB  - Gesamtzentrum für Verkehr (GZVB)
CY  - Braunschweig
ER  - 
TY  - CHAP
A1  - Funke, Harald
A1  - Esch, Thomas
A1  - Roosen, Peter
ED  - Bartz, Wilfried J.
T1  - Using motor gasoline for aircrafts - coping with growing bio-fuel-caused risks by understanding cause-effect relationship
T2  - Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009
N2  - The utilisation of vehicle-oriented gasoline in general aviation is very desirable for both ecological and economical reasons, as well as for general considerations of availability. As of today vehicle fuels may be used if the respective engine and cell are certified for such an operation. For older planes a supplementary technical certificate is provided for gasoline mixtures with less than 1 % v/v ethanol only, though. Larger admixtures of ethanol may lead to sudden engine malfunction and should be considered as considerable security risks. Major problems are caused by the partially ethanol non-withstanding materials, a necessarily changed stochiometric adjustment of the engine for varying ethanol shares and the tendency for phase separation in the presence of absorbed water. The concepts of the flexible fuel vehicles are only partially applicable in the view of air security.
Y1  - 2009
SN  - 978-3-924813-75-8
SP  - 237
EP  - 244
PB  - Technische Akademie Esslingen (TAE)
CY  - Ostfildern
ER  - 
TY  - CHAP
A1  - Horikawa, Atsushi
A1  - Ashikaga, Mitsugu
A1  - Yamaguchi, Masato
A1  - Ogino, Tomoyuki
A1  - Aoki, Shigeki
A1  - Wirsum, Manfred
A1  - Funke, Harald
A1  - Kusterer, Karsten
T1  - Combined heat and power supply demonstration of Micro-Mix Hydrogen Combustion Applied to M1A-17 Gas Turbine
T2  - Proceedings of ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) (Volume 3A)
N2  - Kawasaki Heavy Industries, Ltd. (KHI), Aachen University of Applied Sciences, and B&B-AGEMA GmbH have investigated the potential of low NOx micro-mix (MMX) hydrogen combustion and its application to an industrial gas turbine combustor. Engine demonstration tests of a MMX combustor for the M1A-17 gas turbine with a co-generation system were conducted in the hydrogen-fueled power generation plant in Kobe City, Japan.
This paper presents the results of the commissioning test and the combined heat and power (CHP) supply demonstration. In the commissioning test, grid interconnection, loading tests and load cut-off tests were successfully conducted. All measurement results satisfied the Japanese environmental regulation values. Dust and soot as well as SOx were not detected. The NOx emissions were below 84 ppmv at 15 % O2. The noise level at the site boundary was below 60 dB. The vibration at the site boundary was below 45 dB.
During the combined heat and power supply demonstration, heat and power were supplied to neighboring public facilities with the MMX combustion technology and 100 % hydrogen fuel. The electric power output reached 1800 kW at which the NOx emissions were 72 ppmv at 15 % O2, and 60 %RH. Combustion instabilities were not observed. The gas turbine efficiency was improved by about 1 % compared to a non-premixed type combustor with water injection as NOx reduction method. During a total equivalent operation time of 1040 hours, all combustor parts, the M1A-17 gas turbine as such, and the co-generation system were without any issues.
KW  - industrial gas turbine
KW  - combustor development
KW  - fuels
KW  - hydrogen
KW  - emission
Y1  - 2022
SN  - 978-0-7918-8599-4
U6  - https://doi.org/10.1115/GT2022-81620
N1  - ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition
June 13–17, 2022 Rotterdam, Netherlands
PB  - American Society of Mechanical Engineers
CY  - Fairfield
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Borchers, Kai
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Lange, Caroline
A1  - Maiwald, Volker
A1  - Mikulz, Eugen
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Sasaki, Kaname
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Toth, Norbert
A1  - Wejmo, Elisabet
A1  - Biele, Jens
A1  - Krause, Christian
A1  - Cerotti, Matteo
A1  - Peloni, Alessandro
A1  - Dachwald, Bernd
T1  - Small Spacecraft Solar Sailing for Small Solar System Body Multiple Rendezvous and Landing
T2  - 2018 IEEE Aerospace Conference : 3-10 March 2018
Y1  - 2018
SN  - 978-1-5386-2014-4
ER  - 
TY  - CHAP
A1  - Gierse, Andreas
A1  - Krämer, Stefan
A1  - Daab, Dominique J.
A1  - Hessel, Joana
A1  - Baader, Fabian
A1  - Müller, Brigitte S.
A1  - Wagner, Tobias
A1  - Gdalewitsch, Georg
A1  - Plescher, Engelbert
A1  - Pfützenreuter, Lysan
T1  - Experimental in-flight modal-analysis of a sounding rocket structure
T2  - 21st ESA Symposium on Rocket and Ballon related Research
Y1  - 2013
SN  - 9789290922858
SP  - 341
EP  - 346
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Biele, Jens
A1  - Boden, Ralf
A1  - Ceriotti, Matteo
A1  - Cordero, Federico
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian
A1  - Herčík, David
A1  - Herique, Alain
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Koch, Aaron
A1  - Kofman, Wlodek
A1  - Koncz, Alexander
A1  - Krause, Christian
A1  - Lange, Caroline
A1  - Lichtenheldt, Roy
A1  - Maiwald, Volker
A1  - Mikschl, Tobias
A1  - Mikulz, Eugen
A1  - Montenegro, Sergio
A1  - Pelivan, Ivanka
A1  - Peloni, Alessandro
A1  - Plettemeier, Dirk
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Ruffer, Michael
A1  - Sasaki, Kaname
A1  - Schmitz, Nicole
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Sznajder, Maciej
A1  - Tardivel, Simon
A1  - Toth, Norbert
A1  - Wejmo, Elisabet
A1  - Wolff, Friederike
A1  - Ziach, Christian
T1  - Efficient massively parallel prospection for ISRU by multiple near-earth asteroid rendezvous using near-term solar sails and'now-term'small spacecraft solutions
T2  - 2nd Asteroid Science Intersections with In-Space Mine Engineering – ASIME 2018
N2  - Physical interaction with small solar system bodies (SSSB) is key for in-situ resource utilization (ISRU). The design of mining missions requires good understanding of SSSB properties, including composition, surface and interior structure, and thermal environment. But as the saying goes "If you've seen one asteroid, you've seen one Asteroid": Although some patterns may begin to appear, a stable and reliable scheme of SSSB classification still has to be evolved. Identified commonalities would enable generic ISRU technology and spacecraft design approaches with a high degree of re-use. Strategic approaches require much broader in-depth characterization of the SSSB populations of interest to the ISRU community. The DLR-ESTEC GOSSAMER Roadmap Science Working Groups identified target-flexible Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the missions only feasible with solar sail propulsion, showed the ability to access any inclination and a wide range of heliocentric distances as well as continuous operation close to Earth's orbit where low delta-v objects reside.
Y1  - 2018
N1  - 2nd Asteroid Science Intersections with In-Space Mine Engineering – ASIME 2018
16-17 April 2018, Belval, Luxembourg
SP  - 1
EP  - 33
ER  - 
TY  - CHAP
A1  - Seboldt, Wolfgang
A1  - Dachwald, Bernd
T1  - Solar sails for near-term advanced scientific deep space missions
T2  - Proceedings of the 8th International Workshop on Combustion and Propulsion
N2  - 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.
KW  - solar sail
KW  - low-thrust
KW  - near-Earth asteroid
KW  - sample return
KW  - solar system
Y1  - 2003
N1  - Proceedings of the 8th International Workshop on Combustion and Propulsion. Pozzuoli, Italy, 16 - 21 June 2002.
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Wurm, P.
T1  - Mission analysis for an advanced solar photon thruster
T2  - 60th International Astronautical Congress 2009, IAC 2009
N2  - The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), is a solar sail design concept, for which the two basic functions of the solar sail, namely light collection and thrust direction, are uncoupled. In this paper, we introduce a novel SPT concept, termed the Advanced Solar Photon Thruster (ASPT). This model does not suffer from the simplified assumptions that have been made for the analysis of compound solar sails in previous studies. We present the equations that describe the force, which acts on the ASPT. After a detailed design analysis, the performance of the ASPT with respect to the conventional flat solar sail (FSS) is investigated for three interplanetary mission scenarios: An Earth-Venus rendezvous, where the solar sail has to spiral towards the Sun, an Earth-Mars rendezvous, where the solar sail has to spiral away from the Sun, and an Earth-NEA rendezvous (to near-Earth asteroid 1996FG3), where a large orbital eccentricity change is required. The investigated solar sails have realistic near-term characteristic accelerations between 0.1 and 0.2mm/s2. Our results show that a SPT is not superior to the flat solar sail unless very idealistic assumptions are made.
KW  - Interplanetary flight
Y1  - 2009
SN  - 978-161567908-9
N1  - 60th International Astronautical Congress 2009, IAC 2009; Daejeon; South Korea; 12 October 2009 through 16 October 2009
VL  - 8
SP  - 6838
EP  - 6851
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Thoma, Andreas
A1  - Fisher, Alex
A1  - Braun, Carsten
T1  - Improving the px4 avoid algorithm by bio-inspired flight strategies
T2  - DLRK2020 - „Luft- und Raumfahrt – Verantwortung in allen Dimensionen“
Y1  - 2020
U6  - https://doi.org/10.25967/530183
N1  - Deutscher Luft- und Raumfahrtkongress 2020, 1. bis 3. September 2020 – Online, „Luft- und Raumfahrt – Verantwortung in allen Dimensionen“
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Xu, Changsheng
A1  - Feldmann, Marco
A1  - Plescher, Engelbert
A1  - Digel, Ilya
A1  - Artmann, Gerhard
T1  - Development and testing of a subsurface probe for detection of life in deep ice : [abstract]
N2  - We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named “IceMole”, is currently developed, built, and tested at the FH Aachen University of Applied Sciences’ Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).
KW  - Eisschicht
KW  - Sonde
KW  - subsurface probe
KW  - subsurface ice research
Y1  - 2011
ER  - 
TY  - CHAP
A1  - Peloni, Alessandro
A1  - Ceriotti, Matteo
A1  - Dachwald, Bernd
T1  - Solar-Sailing Trajectory Design for Close-up NEA Observations Mission
T2  - 4th IAA Planetary Defense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy
Y1  - 2015
N1  - IAA-PDC-15-P-19
ER  - 
TY  - CHAP
A1  - Peloni, A.
A1  - Ceriotti, M.
A1  - Dachwald, Bernd
T1  - Preliminary trajectory design of a multiple NEO rendezvous mission through solar sailing
T2  - Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014
Y1  - 2015
SN  - 978-1-63439-986-9
SP  - 5352
EP  - 5366
PB  - Curran
CY  - Red Hook, NY
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Mikucki, Jill A.
A1  - Tulaczyk, Slawek
A1  - Digel, Ilya
A1  - Feldmann, Marco
A1  - Espe, Clemens
A1  - Plescher, Engelbert
A1  - Xu, Changsheng
T1  - IceMole - a maneuverable probe for clean in-situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems : extended abstract / SCAR Open Science Conference 2012, Session 29: Advancing Clean Technologies for Exploration of Glacial Aquatic Ecosystems
N2  - The ”IceMole“ is a novel maneuverable subsurface ice probe for clean in-situ analysis and sampling of subsurface ice and subglacial water/brine. It is developed and build at FH Aachen University of Applied Sciences’ Astronautical Laboratory. A first prototype was successfully tested on the Swiss Morteratsch glacier in 2010. Clean sampling is achieved with a hollow ice screw (as it is used in mountaineering) at the tip of the probe. Maneuverability is achieved with a differentially heated melting head. Funded by the German Space Agency (DLR), a consortium led by FH Aachen currently develops a much more advanced IceMole probe, which includes a sophisticated system for obstacle avoidance, target detection, and navigation in the ice. We intend to use this probe for taking clean samples of subglacial brine at the Blood Falls (McMurdo Dry Valleys, East Antarctica) for chemical and microbiological analysis. In our conference contribution, we 1) describe the IceMole design, 2) report the results of the field tests of the first prototype on the Morteratsch glacier, 3) discuss the probe’s potential for the clean in-situ analysis and sampling of subsurface ice and subglacial liquids, and 4) outline the way ahead in the development of this technology.
KW  - Eisschicht
KW  - Sonde
KW  - subsurface ice
KW  - subglacial aquatic ecosystems
Y1  - 2012
ER  - 
TY  - CHAP
A1  - Kapoor, Hrshi
A1  - Braun, Carsten
A1  - Boller, Christian
ED  - Casciati, Fabio
T1  - Modelling and optimisation of maintenance intervals to realize structural health monitoring applications on aircraft
T2  - Structural health monitoring 2010 : proceedings of the Fifth European Workshop on Structural Health Monitoring held at Sorrento, Naples, Italy, June 28 - July 4, 2010 ; [EWSHM]
Y1  - 2010
SN  - 978-1-60595-024-2
SP  - 55
EP  - 63
PB  - DEStech Publ.
CY  - Lancaster, Pa.
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Biele, Jens
A1  - Boden, Ralf
A1  - Ceriotti, Matteo
A1  - Cordero, Federico
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Herčík, David
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Koch, Aaron D
A1  - Koncz, Alexander
A1  - Krause, Christian
A1  - Lange, Caroline
A1  - Lichtenheldt, Roy
A1  - Maiwald, Volker
A1  - Mikschl, Tobias
A1  - Mikulz, Eugen
A1  - Montenegro, Sergio
A1  - Pelivan, Ivanka
A1  - Peloni, Alessandro
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Ruffer, Michael
A1  - Sasaki, Kaname
A1  - Schmitz, Nicole
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Sznajder, Maciej
A1  - Tardivel, Simon
A1  - Tóth, Norbert
A1  - Wejmo, Elisabet
A1  - Wolff, Friederike
A1  - Ziach, Christian
T1  - Small spacecraft based multiple near-earth asteroid rendezvous and landing with near-term solar sails and ‘Now-Term ‘technologies
T2  - 69 th International Astronautical Congress (IAC)
N2  - 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.
KW  - multiple NEA rendezvous
KW  - solar sail
KW  - GOSSAMER-1
KW  - MASCOT
KW  - small spacecraft
Y1  - 2018
N1  - 69th International Astronautical Congress (IAC), Bremen, Germany, 1-5 October 2018.
https://www.bho-legal.com/1-5-october-2018-69th-international-astronautical-congress-2018-in-bremen-germany/
SP  - 1
EP  - 18
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Boden, Ralf Christian
A1  - Ceriotti, Matteo
A1  - Cordero, Federico
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Hercik, D.
A1  - Herique, A.
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Kofman, Wlodek
A1  - Lange, Caroline
A1  - Lichtenheldt, Roy
A1  - McInnes, Colin R.
A1  - Mikschl, Tobias
A1  - Montenegro, Sergio
A1  - Moore, Iain
A1  - Pelivan, Ivanka
A1  - Peloni, Alessandro
A1  - Plettenmeier, Dirk
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Rogez, Yves
A1  - Ruffer, Michael
A1  - Sasaki, Kaname
A1  - Schmitz, Nicole
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Sznajder, Maciej
A1  - Toth, Norbert
A1  - Viavattene, Giulia
A1  - Wejmo, Elisabet
A1  - Wolff, Friederike
A1  - Ziach, Christian
T1  - Responsive exploration and asteroid characterization through integrated solar sail and lander development using small spacecraft technologies
T2  - IAA Planetary Defense Conference
N2  - 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.
Y1  - 2019
N1  - Conference: IAA Planetary Defense ConferenceAt: Washington DC, USA
29.04-03.05.2019
ER  - 
TY  - CHAP
A1  - Möhren, Felix
A1  - Bergmann, Ole
A1  - Janser, Frank
A1  - Braun, Carsten
T1  - On the determination of harmonic propeller loads
T2  - AIAA SCITECH 2023 Forum
N2  - Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures.
Y1  - 2023
U6  - https://doi.org/10.2514/6.2023-2404
N1  - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, Md & Online
PB  - AIAA
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Global optimization of low-thrust space missions using evolutionary neurocontrol
T2  - Proceedings of the international workshop on global optimization
N2  - 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.
KW  - Evolutionary Neurocontrol
KW  - Spacecraft Trajectory Optimization
KW  - Low-Thrust Propulsion
Y1  - 2005
SP  - 85
EP  - 90
ER  - 
TY  - CHAP
A1  - Schartner, Karl-Heinz
A1  - Loeb, H. W.
A1  - Dachwald, Bernd
A1  - Ohndorf, Andreas
T1  - Perspectives of electric propulsion for outer planetary and deep space missions
T2  - European Planetary Science Congress 2009
N2  - 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].
Y1  - 2009
N1  - European Planetary Science Congress 2009, 13-18 September, Potsdam, Germany
SP  - 416
EP  - 416
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Boden, Ralf
A1  - Ceriotti, Matteo
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Lange, Caroline
A1  - Lichtenheldt, Roy
A1  - Pelivan, Ivanka
A1  - Peloni, Alessandro
A1  - Riemann, Johannes
A1  - Spröwitz, Tom
A1  - Tardivel, Simon
T1  - Soil to sail-asteroid landers on near-term sailcraft as an evolution of the GOSSAMER small spacecraft solar sail concept for in-situ characterization
T2  - 5th IAA Planetary Defense Conference
KW  - multiple NEA rendezvous
KW  - solar sail
KW  - GOSSAMER-1
KW  - MASCOT
KW  - asteroid sample return
Y1  - 2017
N1  - 5th IAA Planetary Defense Conference – PDC 2017
15-19 May 2017, Tokyo, Japan
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Solar sail performance requirements for missions to the outer solar system and beyond
T2  - 55th International Astronautical Congress 2004
N2  - 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.
Y1  - 2004
U6  - https://doi.org/10.2514/6.IAC-04-S.P.11
N1  - 55th International Astronautical Congress 2004 - Vancouver, Canada
SP  - 1
EP  - 9
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Xu, Changsheng
A1  - Feldmann, Marco
A1  - Plescher, Engelbert
T1  - IceMole : Development of a novel subsurface ice probe and testing of the first prototype on the Morteratsch Glacier
T2  - EGU General Assembly 2011 Vienna | Austria | 03 – 08 April 2011
N2  - We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named “IceMole”, is currently developed, built, and tested at the FH Aachen University of Applied Sciences’ Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).
Y1  - 2011
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Biele, Jens
A1  - Dachwald, Bernd
A1  - Grimm, Christian
A1  - Lange, Caroline
A1  - Ulamec, Stephan
T1  - Small spacecraft for small solar system body science, planetary defence and applications
T2  - IEEE Aerospace Conference 2016
N2  - 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.
Y1  - 2016
SP  - 1
EP  - 20
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Biele, Jens
A1  - Cordero, Frederico
A1  - Dachwald, Bernd
A1  - Koncz, Alexander
A1  - Krause, Christian
A1  - Mikschl, Tobias
A1  - Montenegro, Sergio
A1  - Quantius, Dominik
A1  - Ruffer, Michael
A1  - Sasaki, Kaname
A1  - Schmitz, Nicole
A1  - Seefeldt, Patric
A1  - Tóth, Norbert
A1  - Wejmo, Elisabet
T1  - From Sail to Soil – Getting Sailcraft Out of the Harbour on a Visit to One of Earth’s Nearest Neighbours
T2  - 4th IAA Planetary Denfense Conference - PDC 2015,  13-17 April 2015, Frascati, Roma, Italy
Y1  - 2015
ER  - 
TY  - CHAP
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Gomez, Francisco
A1  - Bil, Cees
T1  - On the Applicability of Empirical Drag Estimation Methods for Unmanned Air Vehicle Design   Read More: https://arc.aiaa.org/doi/10.2514/6.2018-3192
T2  - 2018 Aviation Technology, Integration, and Operations Conference, AIAA AVIATION Forum
Y1  - 2018
U6  - https://doi.org/10.2514/6.2018-3192
SN  - 1533-385X
N1  - AIAA 2018-3192
SP  - Article 3192
ER  - 
TY  - CHAP
A1  - Pirovano, Laura
A1  - Seefeldt, Patric
A1  - Dachwald, Bernd
A1  - Noomen, Ron
T1  - Attitude and orbital modeling of an uncontrolled solar-sail experiment in low-Earth orbit
T2  - 25th International Symposium on Space Flight Dynamics ISSFD
N2  - Gossamer-1 is the first project of the three-step Gossamer roadmap, the purpose of which is to develop, prove and demonstrate that solar-sail technology is a safe and reliable propulsion technique for long-lasting and high-energy missions. This paper firstly presents the structural analysis performed on the sail to understand its elastic behavior. The results are then used in attitude and orbital simulations. The model considers the main forces and torques that a satellite experiences in low-Earth orbit coupled with the sail deformation. Doing the simulations for varying initial conditions in attitude and rotation rate, the results show initial states to avoid and maximum rotation rates reached for correct and faulty deployment of the sail. Lastly comparisons with the classic flat sail model are carried out to test the hypothesis that the elastic behavior does play a role in the attitude and orbital behavior of the sail
KW  - Solar sail
KW  - Gossamer structures
KW  - Attitude dynamics
KW  - Orbital dynamics
Y1  - 2015
N1  - 25th International Symposium on Space Flight Dynamics ISSFD
October 19 – 23, 2015, Munich, Germany
https://issfd.org/2015/
SP  - 1
EP  - 15
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Loeb, Horst W.
A1  - Schartner, Karl-Heinz
T1  - A comparison of SEP and NEP for a main belt asteroid sample return mission
T2  - 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007
N2  - Innovative interplanetary deep space missions, like a main belt asteroid sample
return mission, require ever larger velocity increments (∆V s) and thus ever
more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion
systems can significantly enhance or even enable such high-energy missions. In
1995, a European-Russian Joint Study Group (JSG) presented a study report
on “Advanced Interplanetary Missions Using Nuclear-Electric Propulsion”
(NEP). One of the investigated reference missions was a sample return (SR)
from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant,
Topaz-25, however, could not be realized and also the worldwide developments
in space reactor hardware stalled. In this paper, we investigate, whether such
a mission is also feasible using a solar electric propulsion (SEP) system and
compare our SEP results to corresponding NEP results.
Y1  - 2007
SP  - 1
EP  - 10
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Häusler, Bernd
T1  - Performance requirements for near-term interplanetary solar sailcraft missions
T2  - 6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century
N2  - 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.
Y1  - 2002
N1  - 6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century, Versailles, France, 14-16 May 2002
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Kahle, Ralph
A1  - Wie, Bong
T1  - Head-on impact deflection of NEAs: a case study for 99942 Apophis
T2  - Planetary Defense Conference 2007
N2  - 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
Y1  - 2007
N1  - Planetary Defense Conference 2007, Wahington D.C., USA, 05-08 March 2007
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Mayntz, Joscha
A1  - Keimer, Jona
A1  - Dahmann, Peter
A1  - Hille, Sebastian
A1  - Stumpf, Eike
A1  - Fisher, Alex
A1  - Dorrington, Graham
T1  - Electrical Drive and Regeneration in General Aviation Flight with Propellers
T2  - Deutscher Luft- und Raumfahrtkongress 2020
N2  - Electric flight has the potential for a more sustainable and energy-saving way of aviation compared to fossil fuel aviation. The electric motor can be used as a generator inflight to regenerate energy during descent. Three different approaches to regenerating with electric propeller powertrains are proposed in this paper. The powertrain is to be set up in a wind tunnel to determine the propeller efficiency in both working modes as well as the noise emissions. Furthermore, the planned flight tests are discussed. In preparation for these tests, a yaw stability analysis is performed with the result that the aeroplane is controllable during flight and in the most critical failure case. The paper shows the potential for inflight regeneration and addresses the research gaps in the dual role of electric powertrains for propulsion and regeneration of general aviation aircraft.
KW  - Propeller Aerodynamics
KW  - Flight Tests
KW  - Flight Mechanics
KW  - Electrical Flight
KW  - Inflight Regeneration, Recuperation
Y1  - 2022
U6  - https://doi.org/10.25967/530100
N1  - Deutscher Luft- und Raumfahrtkongress 2020, 1. - 3. September 2020, Online
PB  - DGLR
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Braun, Carsten
A1  - Boucke, Alexander
A1  - Ballmann, Josef
T1  - Numerical prediction of the wing deformation of a high speed transport aircraft type wind tunnel model by direct aeroelastic simulation
T2  - Conference proceedings : CEAS/AIAA/DGLR International Forum on Aeroelasticity and Structural Dynamics IFASD 2005 : München, June 28 - July 1, 2005. DGLR-Bericht. 2005,04
Y1  - 2005
SN  - 3-932182-43-X
PB  - DGLR
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Konstantinidis, K.
A1  - Kowalski, Julia
A1  - Martinez, C. F.
A1  - Dachwald, Bernd
A1  - Ewerhart, D.
A1  - Förstner, R.
T1  - Some necessary technologies for in-situ astrobiology on enceladus
T2  - Proceedings of the International Astronautical Congress
Y1  - 2015
SN  - 978-151081893-4
N1  - 6th International Astronautical Congress 2015: Space - The Gateway for Mankind's Future, IAC 2015; Jerusalem; Israel; 12 October 2015 through 16 October 2015
SP  - 1354
EP  - 1372
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results
T2  - European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007
N2  - Interplanetary trajectories for low-thrust spacecraft are often characterized by multiple revolutions around the sun. Unfortunately, the convergence of traditional trajectory optimizers that are based on numerical optimal control methods depends strongly on an adequate initial guess for the control function (if a direct method is used) or for the starting values of the adjoint vector (if an indirect method is used). Especially when many revolutions around the sun are re-
quired, trajectory optimization becomes a very difficult and time-consuming task that involves a lot of experience and expert knowledge in astrodynamics and optimal control theory, because an adequate initial guess is extremely hard to find. Evolutionary neurocontrol (ENC) was proposed as a smart method for low-thrust trajectory optimization that fuses artificial neural networks and evolutionary algorithms to so-called evolutionary neurocontrollers (ENCs) [1]. Inspired by natural archetypes, ENC attacks the trajectoryoptimization problem from the perspective of artificial intelligence and machine learning, a perspective that is quite different from that of optimal control theory. Within the context of ENC, a trajectory is regarded as the result of a spacecraft steering strategy that maps permanently the actual spacecraft state and the actual target state onto the actual spacecraft control vector. This way, the problem of searching the optimal spacecraft trajectory is equivalent to the problem of searching (or "learning") the optimal spacecraft steering strategy. An artificial neural network is used to implement such a spacecraft steering strategy. It can be regarded as a parameterized function (the network function) that is defined by the internal network parameters. Therefore, each distinct set of network parameters defines a different network function and thus a different steering strategy. The problem of searching the optimal steering strategy is now equivalent to the problem of searching the optimal set of network parameters. Evolutionary algorithms that work on a population of (artificial) chromosomes are used to find the optimal network parameters, because the parameters can be easily mapped onto a chromosome. The trajectory optimization problem is solved when the optimal chromosome is found. A comparison of solar sail trajectories that have been published by others [2, 3, 4, 5] with ENC-trajectories has shown that ENCs can be successfully applied for near-globally optimal spacecraft control [1, 6] and that they are able to find trajectories that are closer to the (unknown) global optimum, because they explore the trajectory search space more exhaustively than a human expert can do. The obtained trajectories are fairly accurate with respect to the terminal constraint. If a more accurate trajectory is required, the ENC-solution can be used as an initial guess for a local trajectory optimization method. Using ENC, low-thrust trajectories can be optimized without an initial guess and without expert attendance.
Here, new results for nuclear electric spacecraft and for solar sail spacecraft are presented and it will be shown that ENCs find very good trajectories even for very difficult problems. Trajectory optimization results are presented for 1. NASA's Solar Polar Imager Mission, a mission to attain a highly inclined close solar orbit with a solar sail [7] 2. a mission to de ect asteroid Apophis with a solar sail from a retrograde orbit with a very-high velocity impact [8, 9] 3. JPL's \2nd Global Trajectory Optimization Competition", a grand tour to visit four asteroids from different classes with a NEP spacecraft
Y1  - 2007
ER  - 
TY  - CHAP
A1  - Loeb, Horst W.
A1  - Schartner, Karl-Heinz
A1  - Seboldt, Wolfgang
A1  - Dachwald, Bernd
A1  - Streppel, Joern
A1  - Meusemann, Hans
A1  - Schülke, Peter
T1  - SEP for a lander mission to the jovian moon europa
T2  - 57th International Astronautical Congress
N2  - 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.
Y1  - 2006
U6  - https://doi.org/10.2514/6.IAC-06-C4.4.04
N1  - 57th International Astronautical Congress, 02 October 2006 - 06 October 2006, Valencia, Spain.
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Gehler, M.
A1  - Ober-Blöbaum, S.
A1  - Dachwald, Bernd
T1  - Application of discrete mechanics and optimal control to spacecraft in non-keplerian motion around small solar system bodies
T2  - Procceedings of the 60th International Astronautical Congress
N2  - Prolonged operations close to small solar system bodies require a sophisticated control logic to minimize propellant mass and maximize operational efficiency. A control logic based on Discrete Mechanics and Optimal Control (DMOC) is proposed and applied to both conventionally propelled and solar sail spacecraft operating at an arbitrarily shaped asteroid in the class of Itokawa. As an example, stand-off inertial hovering is considered, recently identified as a challenging part of the Marco Polo mission. The approach is easily extended to stand-off orbits. We show that DMOC is applicable to spacecraft control at small objects, in particular with regard to the fact that the changes in gravity are exploited by the algorithm to optimally control the spacecraft position. Furthermore, we provide some remarks on promising developments.
KW  - Spacecraft
Y1  - 2009
SN  - 978-161567908-9
N1  - 60th International Astronautical Congress 2009, IAC 2009; Daejeon; South Korea; 12 October 2009 through 16 October 2009
SP  - 1360
EP  - 1371
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Kallweit, Stephan
A1  - Schleupen, Josef
A1  - Dahmann, Peter
A1  - Bagheri, Mohsen
A1  - Engemann, Heiko
T1  - Entwicklung eines Kletterroboters zur Diagnose und Instandsetzung von Windenergieanlagen (SMART)
T2  - Automatisierung im Fokus von Industrie 4.0 : Tagungsband AALE 2016 ; 13. Fachkonferenz, Lübeck
Y1  - 2016
SN  - 978-3-8356-7312-0
N1  - AALE-Konferenz <13., 2016, Lübeck>
SP  - 207
EP  - 212
PB  - DIV Deutscher Industrieverlag GmbH
CY  - München
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Radiation pressure force model for an ideal laser-enhanced solar sail
T2  - 4th International Symposium on Solar Sailing
N2  - 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.
Y1  - 2017
N1  - 4th International Symposium on Solar Sailing
17-20 January 2017, Kyōto, Japan
SP  - 1
EP  - 5
ER  - 
TY  - CHAP
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Case studies in initial sizing for hybrid-electric general aviation aircraft
T2  - 2018 AIAA/IEEE Electric Aircraft Technologies Symposium, Cincinnati, Ohio
Y1  - 2018
U6  - https://doi.org/10.2514/6.2018-5005
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Baturkin, Volodymyr
A1  - Coverstone, Victoria
A1  - Diedrich, Ben
A1  - Garbe, Gregory
A1  - Görlich, Marianne
A1  - Leipold, Manfred
A1  - Lura, Franz
A1  - Macdonald, Malcolm
A1  - McInnes, Colin
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro
A1  - Rios-Reyes, Leonel
A1  - Scheeres, Daniel J.
A1  - Seboldt, Wolfgang
A1  - Wie, Bong
T1  - Potential effects of optical solar sail degredation on trajectory design
T2  - AAS/AIAA Astrodynamics Specialist
N2  - 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.
Y1  - 2005
N1  - 2005 AAS/AIAA Astrodynamics Specialist Conference, 7-11.08.2005. Lake Tahoe, California
https://www.space-flight.org/AAS_meetings/2005_astro/2005_astro.html
SP  - 1
EP  - 23
ER  - 
TY  - CHAP
A1  - Waldmann, Christoph
A1  - Vera, Jean-Pierre de
A1  - Dachwald, Bernd
A1  - Strasdeit, Henry
A1  - Sohl, Frank
A1  - Hanff, Hendrik
A1  - Kowalski, Julia
A1  - Heinen, Dirk
A1  - Macht, Sabine
A1  - Bestmann, Ulf
A1  - Meckel, Sebastian
A1  - Hildebrandt, Marc
A1  - Funke, Oliver
A1  - Gehrt, Jan-Jöran
T1  - Search for life in ice-covered oceans and lakes beyond Earth
T2  - 2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761
N2  - 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.
KW  - Planetary exploration
KW  - Jupiter
KW  - ice moons
KW  - underwater vehicle
KW  - Antarctica
Y1  - 2018
U6  - https://doi.org/10.1109/AUV.2018.8729761
ER  - 
TY  - CHAP
A1  - Duprat, J.
A1  - Dachwald, Bernd
A1  - Hilchenbach, M.
A1  - Engrand, Cecile
A1  - Espe, C.
A1  - Feldmann, M.
A1  - Francke, Gero
A1  - Görög, Mark
A1  - Lüsing, N.
A1  - Langenhorst, Falko
T1  - The MARVIN project: a micrometeorite harvester in Antarctic snow
T2  - 44th Lunar and Planetary Science Conference
N2  - MARVIN is an automated drilling and melting probe dedicated to collect pristine interplanetary dust particles (micrometeorites) from central Antarctica snow.
Y1  - 2013
N1  - 44th Lunar and Planetary Science Conference, March 18-22, 2013, The Woodlands, Texas
ER  - 
TY  - CHAP
A1  - Finger, Felix
A1  - Khalsa, R.
A1  - Kreyer, Jörg
A1  - Mayntz, Joscha
A1  - Braun, Carsten
A1  - Dahmann, Peter
A1  - Esch, Thomas
A1  - Kemper, Hans
A1  - Schmitz, O.
A1  - Bragard, Michael
T1  - An approach to propulsion system modelling for the conceptual design of hybrid-electric general aviation aircraft
T2  - Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt
N2  - In this paper, an approach to propulsion system modelling for hybrid-electric general aviation aircraft is presented. Because the focus is on general aviation aircraft, only combinations of electric motors and reciprocating combustion engines are explored. Gas turbine hybrids will not be considered. The level of the component's models is appropriate for the conceptual design stage. They are simple and adaptable, so that a wide range of designs with morphologically different propulsive system architectures can be quickly compared. Modelling strategies for both mass and efficiency of each part of the propulsion system (engine, motor, battery and propeller) will be presented.
Y1  - 2019
ER  - 
TY  - CHAP
A1  - Finger, Felix
A1  - de Vries, Reynard
A1  - Vos, Roelof
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - A comparison of hybrid-electric aircraft sizing methods
T2  - AIAA Scitech 2020 Forum
N2  - The number of case studies focusing on hybrid-electric aircraft is steadily increasing, since these configurations are thought to lead to lower operating costs and environmental impact than traditional aircraft. However, due to the lack of reference data of actual hybrid-electric aircraft, in most cases, the design tools and results are difficult to validate. In this paper, two independently developed approaches for hybrid-electric conceptual aircraft design are compared. An existing 19-seat commuter aircraft is selected as the conventional baseline, and both design tools are used to size that aircraft. The aircraft is then re-sized under consideration of hybrid-electric propulsion technology. This is performed for parallel, serial, and fully-electric powertrain architectures. Finally, sensitivity studies are conducted to assess the validity of the basic assumptions and approaches regarding the design of hybrid-electric aircraft. Both methods are found to predict the maximum take-off mass (MTOM) of the reference aircraft with less than 4% error. The MTOM and payload-range energy efficiency of various (hybrid-) electric configurations are predicted with a maximum difference of approximately 2% and 5%, respectively. The results of this study confirm a correct formulation and implementation of the two design methods, and the data obtained can be used by researchers to benchmark and validate their design tools.
Y1  - 2020
U6  - https://doi.org/10.2514/6.2020-1006
N1  - AIAA Scitech 2020 Forum, Driving aerospace solutions for global challenges, Orlando, 06. - 10. January 2020
ER  - 
TY  - CHAP
A1  - Thenent, N. E.
A1  - Dahmann, Peter
T1  - Increasing aircraft design flexibility ‐ The development of a hydrostatic transmission for gliders with self‐launching capability
T2  - Deutscher Luft- und Raumfahrtkongress 2011 : Bremen, 27. bis 29. September 2011 ; Tagungsband
Y1  - 2011
SN  - 978-3-9321-8274-7
SP  - 865
EP  - 883
PB  - Dt. Gesellschaft für Luft- und Raumfahrt
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Finger, Felix
A1  - Götten, Falk
A1  - Braun, Carsten
T1  - Initial Sizing for a Family of Hybrid-Electric VTOL General Aviation Aircraft
T2  - 67. Deutscher Luft- und Raumfahrtkongress 2018
Y1  - 2018
ER  - 
TY  - CHAP
A1  - Digel, Ilya
A1  - Dachwald, Bernd
A1  - Artmann, Gerhard
A1  - Linder, Peter
A1  - Funke, O.
T1  - A concept of a probe for particle analysis and life detection in icy environments
N2  - A melting probe equipped with autofluorescence-based detection system combined with a light scattering unit, and, optionally, with a microarray chip would be ideally suited to probe icy environments like Europa’s ice layer as well as the polar ice layers of Earth and Mars for recent and extinct live.
KW  - Sonde
KW  - Eisschicht
KW  - Autofluoreszenzverfahren
KW  - Lichtstreuungsbasierte Instrumente
KW  - autofluorescence-based detection system
KW  - light scattering analysis
Y1  - 2009
ER  - 
TY  - CHAP
A1  - Ludowicy, Jonas
A1  - Rings, René
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Impact of Propulsion Technology Levels on the Sizing and Energy Consumption for Serial HybridElectric General Aviation Aircraft
T2  - Asia Pacific International Symposium on Aerospace Technology. APISAT 2019
Y1  - 2019
ER  - 
TY  - CHAP
A1  - Thenent, N. E.
A1  - Dahmann, Peter
T1  - Hydrostatic propeller drive
T2  - Proceedings of the conference : 18 - 20 May, 2011 Tampere, Finland / the Twelth Scandinavian International Conference on Fluid Power, SICFP'11. Ed.: Harri Sairiala ... Vol. 1
Y1  - 2011
SN  - 978-952-15-2517-9
SP  - 217
EP  - 227
CY  - Tampere
ER  - 
TY  - CHAP
A1  - Korsch, Helge
A1  - Dafnis, Athanasios
A1  - Reimerdes, Hans-Günther
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Dynamic qualification of the HIRENASD elastic wing model
T2  - Motto: Luft- und Raumfahrt: Lehre, Forschung, Industrie - gemeinsam innovativ. Deutscher Luft- und Raumfahrtkongress 2006 : Braunschweig, 06. bis 09. November 2006. Jahrbuch / Deutsche Gesellschaft für Luft- und Raumfahrt. 2006
Y1  - 2006
SP  - 1441
EP  - 1450
PB  - Dt. Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth (DGLR)
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Niedermeier, H.
A1  - Clemens, J.
A1  - Kowalski, Julia
A1  - Macht, S.
A1  - Heinen, D.
A1  - Hoffmann, R.
A1  - Linder, Peter
T1  - Navigation system for a research ice probe for antarctic glaciers
T2  - IEEE/ION Position, Location and Navigation Symposium (PLANS) ; 5-8 May 2014, Monterey, Calif.
Y1  - 2014
SN  - 978-1-4799-3319-8
SP  - 959
EP  - 975
PB  - IEEE
CY  - Piscataway, NJ
ER  -