TY - JOUR A1 - Dachwald, Bernd T1 - Minimum Transfer Times for Nonperfectly Reflecting Solar Sailcraft JF - Journal of Spacecraft and Rockets. 41 (2004), H. 4 Y1 - 2004 SN - 0022-4650 N1 - 2. ISSN: 1533-6794 SP - 693 EP - 695 ER - TY - JOUR A1 - Dachwald, Bernd T1 - Optimization of Interplanetary Solar Sailcraft Trajectories Using Evolutionary Neurocontrol JF - Journal of guidance, control, and dynamics. 27 (2004), H. 1 Y1 - 2004 SN - 0162-3192 N1 - 2. ISSN: 0162-3192. - 3. ISSN: 0731-5090 SP - 66 EP - 72 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 - Seboldt, Wolfgang A1 - Blome, Hans-Joachim A1 - Dachwald, Bernd A1 - Richter, Lutz T1 - Proposal for an integrated European space exploration strategy T2 - 55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law N2 - 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. Y1 - 2004 N1 - 55th International Astronautical Congress 2004 - Vancouver, Canada SP - 1 EP - 10 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Schmidt, Tanja D. A1 - Seboldt, Wolfgang A1 - Auweter-Kurtz, T1 - Flight Opportunities from Mars to Earth for Piloted Missions Using Continuous Thrust Propulsion / Schmidt, Tanja D. ; Dachwald, Bernd ; Seboldt, Wolfgang ; Auweter-Kurtz, Monika Y1 - 2003 N1 - 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 20-23 July 2003, Huntsville, Alabama ; AIAA 2003-4573 SP - 1 EP - 9 PB - - ER - TY - JOUR A1 - Havermann, Marc A1 - Seiler, F. A1 - George, A. A1 - Leopold, F. T1 - Planar Velocity Visualization in High-Speed Wedge Flow using Doppler Picture Velocimetry (DPV) compared with Particle Image Velocimetry (PIV) / Seiler, F. ; Havermann, M. ; George, A. ; Leopold, F. ; Srulijes, J. JF - Journal of Visualization. 6 (2003), H. 3 Y1 - 2003 SN - 1343-8875 SP - 253 EP - 262 PB - - ER - TY - CHAP A1 - Ballmann, Josef A1 - Boucke, Alexander A1 - Braun, Carsten T1 - Aeroelastic sensitivity in the transonic regime T2 - Symposium Transsonicum IV : proceedings of the IUTAM symposium held in Göttingen, Germany, 2 - 6 September 2002 / ed. by Helmut Sobieczky. Fluid mechanics and its applications. Vol. 73 Y1 - 2003 SN - 978-94-010-3998-7 SP - 225 EP - 236 PB - Kluwer Academic CY - Dordrecht ER - TY - CHAP A1 - Britten, G. A1 - Braun, Carsten A1 - Hesse, M. A1 - Ballmann, Josef T1 - Computational aeroelasticity with reduced structural models T2 - Flow modulation and fluid-structure interaction at airplane wings : research results of the Collaborative Research Center SFB 401 at RWTH Aachen, University of Technology, Aachen, Germany / Josef Ballmann (Ed.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 84 Y1 - 2003 SN - 3-540-40209-8 SP - 275 EP - 299 PB - Springer CY - Berlin ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, W. A1 - Richter, L. T1 - Multiple Rendezvous and Sample Return Missions to Near-Earth Asteroids Using Solar Sailcraft JF - Proceedings of the Fifth IAA International Conference on Low Cost Planetary Missions : 24 - 26 September 2003, ESTEC, Noordwijk, the Netherlands / [comp. by R. A. Harris] Y1 - 2003 SN - 92-9092-853-0 N1 - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; International Academy of Astronautics ; European Space Research and Technology Centre SP - 351 EP - 358 PB - ESA CY - Noordwijk ER - TY - JOUR A1 - Dachwald, Bernd A1 - Leipold, M. A1 - Fichtner, H. T1 - Heliopause Explorer - A Sailcraft Mission to the Outer Boundaries of the Solar System / M. Leipold ; H. Fichtner ; B. Heber ... B. Dachwald ... JF - Proceedings of the Fifth IAA International Conference on Low Cost Planetary Missions : 24 - 26 September 2003, ESTEC, Noordwijk, the Netherlands / [comp. by R. A. Harris] Y1 - 2003 SN - 92-9092-853-0 N1 - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; International Academy of Astronautics ; European Space Research and Technology Centre SP - 367 EP - 375 PB - ESA CY - Noordwijk ER - TY - JOUR A1 - Bohn, Dieter A1 - Funke, Harald T1 - Experimental investigations into the nonuniform flow in a 4-stage turbine with special focus on the flow equalization in the first turbine stage JF - ASME TURBO EXPO, Proceedings of the ASME Turbo Expo, 2003 Y1 - 2003 SN - 0-7918-3689-4 N1 - ASME TURBO EXPO 2003, Proceedings, Vol. 6: Turbomachinery, Pt. A, Atlanta, US, Jun 16-19, 2003 SP - 281 EP - 289 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang T1 - Solar sailcraft of the first generation mission applications to near-earth asteroids Y1 - 2003 N1 - 54th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law 29 September - 3 October 2003, Bremen, Germany IAC-03-Q.5.06 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang T1 - Solar sailcraft of the first generation technology development / Seboldt, Wolfgang ; Dachwald, Bernd Y1 - 2003 N1 - 54th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law 29 September - 3 October 2003, Bremen, Germany IAC-03-S.03 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 - JOUR A1 - Esch, Thomas A1 - Salber, Wolfgang A1 - Wolters, Peter A1 - Geiger, José A1 - Dilthey, Jochen T1 - Synergies of variable valve actuation and direct injection JF - Direct injection SI engine technology 2002 : [SAE 2002 world congress, Detroit, Michigan, USA, March 4 - 7, 2002]. Y1 - 2002 SN - 0-7680-0961-8 N1 - Konferenz-Einzelbericht SP - 45 EP - 53 PB - Society of Automotive Engineers CY - Warrendale, Pa ER - TY - BOOK A1 - Havermann, Marc A1 - Ende, Herrybert A1 - Schwenzer, Michael T1 - Shock tunnel study on the interaction of a lateral jet with a supersonic cross flow : West East High-Speed Flow Field Conference, Marseille, France, April 22 - 26, 2002; axe de recherches 2.14 / Havermann, M.; Ende, H.; Schwenzer, M. Institut Franco-Allemand de Recherches de Saint-Louis Y1 - 2002 N1 - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 620 PB - ISL CY - Saint-Louis ER - TY - BOOK A1 - Havermann, Marc A1 - Haertig, J. A1 - Rey, C. A1 - George, A. T1 - Application of particle image velocimetry to high-speed supersonic flows in a shock tunnel : 11th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, Portugal, July 8 - 11, 2002; Schwerpunkt 0 / Institut Franco-Allemand de Recherches de Saint-Louis. Havermann, M. ... Y1 - 2002 N1 - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 640 PB - ISL CY - Saint-Louis ER - TY - JOUR A1 - Havermann, Marc A1 - Haertig, J. A1 - Rey, C. A1 - George, A. T1 - Particle image velocimetry in mach 3.5 and 4.5 shock-tunnel flows / Haertig, J. ; Havermann, M. ; Rey, C. ; George, A. JF - AIAA journal. 40 (2002), H. 6 Y1 - 2002 SN - 0001-1452 N1 - Printausgabe in der Bereichsbibliothek Eupener Str. Signatur: 23 Z 701 SP - 1056 EP - 1060 PB - - ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, W. T1 - Optimization of Interplanetary Rendezvous Trajectories for Solar Sailcraft Using a Neurocontroller JF - A collection of technical papers / AIAA Astrodynamics Specialist Conference : Monterey, California, 5 - 8 August 2002. - Vol. 2 Y1 - 2002 SN - 1-56347-549-9 N1 - Astrodynamics Specialist Conference <2002, Monterey, Calif.> American Institute of Aeronautics and Astronautics ; AIAA paper number: AIAA-2002-4989 SP - 1263 EP - 1270 PB - American Institute of Aeronautics and Astronautics CY - Reston, Va. ER - TY - PAT A1 - Mertens, Josef A1 - Lajain, Henri T1 - Method of fabricating leading edge nose structures of aerodynamic surfaces : patent no.: US 6,415,510 B2 ; date of patent: Jul. 9, 2002 Y1 - 2002 N1 - Volltext auch in der Datenbank http://publikationen.dpma.de/ zu finden unter der Nummer US000006415510B2 PB - United States Patent and Trademark Office CY - [Washington, DC] ER -