@article{DachwaldSchmidtSeboldtetal.2003, author = {Dachwald, Bernd and Schmidt, Tanja D. and Seboldt, Wolfgang and Auweter-Kurtz,}, title = {Flight Opportunities from Mars to Earth for Piloted Missions Using Continuous Thrust Propulsion / Schmidt, Tanja D. ; Dachwald, Bernd ; Seboldt, Wolfgang ; Auweter-Kurtz, Monika}, publisher = {-}, pages = {1 -- 9}, year = {2003}, language = {en} } @article{HeinrichsPietrzykZiemons2003, author = {Heinrichs, U. and Pietrzyk, U. and Ziemons, Karl}, title = {Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3}, series = {2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, journal = {2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, issn = {1082-3654}, pages = {682 -- 686}, year = {2003}, abstract = {Within the Crystal Clear Collaboration four centres are developing 2nd generation high performance small animal PET scanners for different kinds of animals and medical applications. The first prototypes are PMT-based systems including depth of interaction (DOI) detection by using a phoswich layer of LSO and LuYAP. The aim of these simulation studies is to optimize sensitivity and spatial resolution of given designs, which vary in FOVs caused by different detector configurations (ring/octagon) and sizes. For this purpose the simulation tool GEANT3 (CERN) was used. The simulations have shown that all PMT designs with one-to-one coupling of crystals have a very nonlinear axial sensitivity profile. By shifting every other PMT 1/4 of a PMT length in axial direction the sampling of the FOVs became more homogeneous. At an energy threshold of 350keV the regression coefficient increases from 0.818 for the non-shifted to 0.993 for the shifted design. Simulations of a point source centred in the FOV (threshold: 350keV) resulted in sensitivities of 4.2\% for a 4×20PMT (LSO/LuYAP a 10mm) and 3.8\% for a 4×16PMT (LSO/LuYAP a 8mm) ring design. The 3D-MLEM reconstruction of a point source shows the enormous improvement of resolution using a crystal double layer with DOI (3.1mm at 40mm from CFOV) instead of a 20mm single layer (11.9mm).}, language = {en} } @article{HeinrichsPietrzykZiemons2003, author = {Heinrichs, U. and Pietrzyk, U. and Ziemons, Karl}, title = {Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3}, series = {IEEE Transactions on Nuclear Science}, volume = {50}, journal = {IEEE Transactions on Nuclear Science}, number = {5}, isbn = {0018-9499}, pages = {1428 -- 1432}, year = {2003}, abstract = {Within the Crystal Clear Collaboration (CCC), four centers are developing second generation high performance small animal positron emission tomography (PET) scanners for different kinds of animals and medical applications. The first prototypes are photomultiplier tube (PMT)-based systems including depth of interaction (DOI) detection by using a phoswich layer of lutetium oxyorthosilicate (LSO) and lutetium yttrium aluminum perovskite (LuYAP). The aim of these simulation studies is to optimize sensitivity and spatial resolution of given designs, which vary in fields of view (FOVs) caused by different detector configurations (ring/octagon) and sizes. For this purpose the simulation tool GEANT3 (CERN, Geneva, Switzerland) was used.}, language = {en} } @article{StreunBrandenburgLarueetal.2003, author = {Streun, M. and Brandenburg, G. and Larue, H. and Saleh, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.}, title = {Pulse shape discrimination of LSO and LuYAP scintillators for depth of interaction detection in PET}, series = {2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, journal = {2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, issn = {1082-3654}, pages = {1636 -- 1639}, year = {2003}, abstract = {A feasible way to gain the depth of interaction information in a PET scanner is the use of phoswich detectors. In general the layer of interaction is identified front the pulse shape of the corresponding scintillator material. In this work pulses from LSO and LuYAP crystals were investigated in order to find a practical method of distinguishing. It turned out that such a pulse processing could he kept simple due to an additional slow component in the light decay of the LuYAP pulse. At the same time the short decay time guarantees that the major amount of the light output is still collected within a short pulse recording time.}, language = {en} } @article{StreunBrandenburgLarueetal.2003, author = {Streun, M. and Brandenburg, G. and Larue, H. and Saleh, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.}, title = {Pulse shape discrimination of LSO and LuYAP scintillators for depth of interaction detection in PET}, series = {IEEE Transactions on Nuclear Science}, volume = {50}, journal = {IEEE Transactions on Nuclear Science}, number = {3}, isbn = {0018-9499}, pages = {344 -- 347}, year = {2003}, abstract = {A feasible way to gain the depth of interaction information in a positron emission tomography scanner is the use of phoswich detectors. In general, the layer of interaction is identified from the pulse shape of the corresponding scintillator material. In this work, pulses from LSO and LuYAP crystals were investigated in order to find a practical method of distinguishing. It turned out that such a pulse processing could be kept simple because of an additional slow component in the light decay of the LuYAP pulse. At the same time, the short decay time guarantees that the major amount of the light output is still collected within a short pulse recording time.}, language = {en} } @inproceedings{RingbeckAlbrechtFreyetal.2003, author = {Ringbeck, Thorsten and Albrecht, M. and Frey, J. and [u.a.],}, title = {Time-of-Flight 3D-camera for autonomous navigation and industrial automation}, series = {Proceedings : 11th international conference, 13 - 15 May 2003, Exhibition Centre Nuremberg, Germany ; an event of the Association for Sensor Technology, AMA}, booktitle = {Proceedings : 11th international conference, 13 - 15 May 2003, Exhibition Centre Nuremberg, Germany ; an event of the Association for Sensor Technology, AMA}, editor = {Lerch, Reinhard}, edition = {CD-ROM-Ausg.}, publisher = {AMA Service}, address = {Wunstorf/Germany}, year = {2003}, language = {en} } @incollection{BallmannBouckeBraun2003, author = {Ballmann, Josef and Boucke, Alexander and Braun, Carsten}, title = {Aeroelastic sensitivity in the transonic regime}, series = {Symposium Transsonicum IV : proceedings of the IUTAM symposium held in G{\"o}ttingen, Germany, 2 - 6 September 2002 / ed. by Helmut Sobieczky. Fluid mechanics and its applications. Vol. 73}, booktitle = {Symposium Transsonicum IV : proceedings of the IUTAM symposium held in G{\"o}ttingen, Germany, 2 - 6 September 2002 / ed. by Helmut Sobieczky. Fluid mechanics and its applications. Vol. 73}, publisher = {Kluwer Academic}, address = {Dordrecht}, isbn = {978-94-010-3998-7}, pages = {225 -- 236}, year = {2003}, language = {en} } @incollection{BrittenBraunHesseetal.2003, author = {Britten, G. and Braun, Carsten and Hesse, M. and Ballmann, Josef}, title = {Computational aeroelasticity with reduced structural models}, series = {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}, booktitle = {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}, publisher = {Springer}, address = {Berlin}, isbn = {3-540-40209-8}, pages = {275 -- 299}, year = {2003}, language = {en} } @article{PalmerLindemann2003, author = {Palmer, J. W. and Lindemann, Markus}, title = {Business models and market mechanisms : evaluating efficiency in consumer electronic markets}, series = {Data base and advanced information systems. Bd. 34 (2003), H. 2}, journal = {Data base and advanced information systems. Bd. 34 (2003), H. 2}, issn = {0105-9912}, pages = {23 -- 38}, year = {2003}, language = {en} } @inproceedings{SchwarzerVieiraMuelleretal.2003, author = {Schwarzer, Klemens and Vieira, Maria Eugenia and M{\"u}ller, Christoph and Lehmann, Harry and Coutinho, Lecimara}, title = {Modular solar thermal desalination system with flat plate collector}, series = {RIO 3 - World Climate \& Energy Event : proceedings of the international conference held in Rio de Janeiro, Brazil, 1 -5 december 2003 / chief-ed.: Stefan Krauter ...}, booktitle = {RIO 3 - World Climate \& Energy Event : proceedings of the international conference held in Rio de Janeiro, Brazil, 1 -5 december 2003 / chief-ed.: Stefan Krauter ...}, publisher = {Krauter}, address = {Rio de Janeiro}, isbn = {85-902710-2-1}, pages = {281 -- 286}, year = {2003}, language = {en} } @inproceedings{SedlacekGesslerSchleseretal.2003, author = {Sedlacek, G. and Geßler, A. and Schleser, Markus and Mund, F. and V{\"o}lling, B.}, title = {Verbindungen vorgefertigter Textilbetonbauteile}, series = {Textile reinforced structures : proceedings of the 2nd Colloquium on Textile Reinforced Structures (CTRS2), Dresden, Germany, 29.9. - 1.10.2003}, booktitle = {Textile reinforced structures : proceedings of the 2nd Colloquium on Textile Reinforced Structures (CTRS2), Dresden, Germany, 29.9. - 1.10.2003}, publisher = {Techn. Univ.}, address = {Dresden}, organization = {Colloquium on Textile Reinforced Structures <2, 2003, Dresden>}, isbn = {3-86005-386-8}, pages = {481 -- 493}, year = {2003}, language = {en} } @article{KraemerBongaertsBovenbergetal.2003, author = {Kr{\"a}mer, Marco and Bongaerts, Johannes and Bovenberg, Roel and Kremer, Susanne and M{\"u}ller, Ulrike and Orf, Sonja and Wubbolts, Marcel and Raeven, Leon}, title = {Metabolic engineering for microbial production of shikimic acid}, series = {Metabolic engineering}, volume = {Vol. 5}, journal = {Metabolic engineering}, number = {Iss. 4}, issn = {1096-7184 (E-Journal); 1096-7176 (Print)}, pages = {277 -- 283}, year = {2003}, language = {en} } @article{HellwigVolkmann2003, author = {Hellwig, Angelika and Volkmann, Lutz}, title = {Maximally edge-connected digraphs}, series = {Australasian journal of combinatorics}, volume = {Vol. 27}, journal = {Australasian journal of combinatorics}, issn = {1034-4942 (E-Journal); 1034-4942 (Print)}, pages = {23 -- 32}, year = {2003}, language = {en} } @inproceedings{DoeringZillerHortmanns2003, author = {D{\"o}ring, Bernd and Ziller, Claudia and Hortmanns, M.}, title = {Ventilation of double facades by external dynamic wind pressure}, series = {11th International Conference on Wind Engineering. 1}, booktitle = {11th International Conference on Wind Engineering. 1}, publisher = {The Wind Science and Engineering Research Center}, address = {Lubbock, Tex.}, organization = {International Conference on Wind Engineering <11, 2003, Lubbock, Tex.>}, pages = {721 -- 730}, year = {2003}, language = {en} } @inproceedings{ZillerDoering2003, author = {Ziller, Claudia and D{\"o}ring, Bernd}, title = {Influence of the external dynamic wind pressure on the ventilation of double facades}, series = {Research in building physics: proceedings of the Second International Conference on Building Physics : Leuven, Belgium, 14-18 September 2003}, booktitle = {Research in building physics: proceedings of the Second International Conference on Building Physics : Leuven, Belgium, 14-18 September 2003}, editor = {Carmeliet, J. and Hens, H. and Vermeir, G.}, publisher = {Taylor and Francis}, address = {Hoboken}, organization = {International Conference on Building Physics <2, 2003, Leuven>}, isbn = {9058095657, 9789058095657}, pages = {527 -- 533}, year = {2003}, language = {en} } @inproceedings{DetertGligorevicHaaketal.2003, author = {Detert, T. and Gligorevic, Snjezana and Haak, W. and Sorger, Ulrich}, title = {Maximum-likelihood channel estimation using the spreading matrix in fast time-variant frequency selective channels}, series = {Proceedings of the 3rd IEEE International Symposium on Signal Processing and Information Technology, ISSPIT 2003 : 14 - 17 December 2003, Darmstadt, Germany}, booktitle = {Proceedings of the 3rd IEEE International Symposium on Signal Processing and Information Technology, ISSPIT 2003 : 14 - 17 December 2003, Darmstadt, Germany}, organization = {Institute of Electrical and Electronics Engineers}, isbn = {0-7803-8292-7}, pages = {347 -- 350}, year = {2003}, language = {en} } @inproceedings{DyllaFerreinLakemeyer2003, author = {Dylla, Frank and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {AllemaniACs 2003 team description}, series = {RoboCup 2003 : Robot Soccer World Cup VII}, booktitle = {RoboCup 2003 : Robot Soccer World Cup VII}, pages = {1 -- 3}, year = {2003}, language = {en} } @inproceedings{MoritzYoshinobuFingeretal.2003, author = {Moritz, Werner and Yoshinobu, Tatsuo and Finger, Friedhelm and Krause, Steffi and Sch{\"o}ning, Michael Josef}, title = {Amorphous silicon as semiconductor material for high resolution LAPS}, series = {Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimar{\~a}es, Portugal, September 21 - 24, 2003}, booktitle = {Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimar{\~a}es, Portugal, September 21 - 24, 2003}, pages = {48 -- 49}, year = {2003}, language = {en} } @inproceedings{ErmelenkoYoshinobuMourzinaetal.2003, author = {Ermelenko, Y. and Yoshinobu, T. and Mourzina, Y. and Sch{\"o}ning, Michael Josef and Vlasov, Y. and Iwasaki, H.}, title = {A multisensor based on laser scanned silicon transducer (LSST): development and properties}, series = {Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimar{\~a}es, Portugal, September 21 - 24, 2003}, booktitle = {Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimar{\~a}es, Portugal, September 21 - 24, 2003}, pages = {72 -- 73}, year = {2003}, language = {en} } @inproceedings{YoshinobuSchoeningFingeretal.2003, author = {Yoshinobu, T. and Sch{\"o}ning, Michael Josef and Finger, F. and Moritz, W. and Iwasaki, H.}, title = {Thin-film a-Si LAPS : Preparation and pH sensitivity}, series = {Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimar{\~a}es, Portugal, September 21 - 24, 2003}, booktitle = {Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimar{\~a}es, Portugal, September 21 - 24, 2003}, pages = {88 -- 89}, year = {2003}, language = {en} } @article{BaroudWuBohneretal.2003, author = {Baroud, G. and Wu, J.Z. and Bohner, M and Sponagel, Stefan and Steffen, T.}, title = {How to determine the permeability for cement infiltration into osteoporotic cancellous bone}, series = {Medical Engineering \& Physics. 25 (2003), H. 4}, journal = {Medical Engineering \& Physics. 25 (2003), H. 4}, issn = {1350-4533}, pages = {283 -- 288}, year = {2003}, abstract = {Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63\% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.}, subject = {Osteoporose}, language = {en} } @article{Staat2003, author = {Staat, Manfred}, title = {Shakedown and ratchetting under tension-torsion loadings: analysis and experiments}, year = {2003}, abstract = {Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.}, subject = {Einspielen }, language = {en} } @inproceedings{Staat2003, author = {Staat, Manfred}, title = {Design by Analysis of Pressure Components by non-linear Optimization}, year = {2003}, abstract = {This paper presents the direct route to Design by Analysis (DBA) of the new European pressure vessel standard in the language of limit and shakedown analysis (LISA). This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for some examples from the DBA-Manual. One observation from the examples is, that the optimisation approach gives reliable and close lower bound solutions leading to simple and optimised design decision.}, language = {en} } @article{KaemperPicardBrilletal.2003, author = {K{\"a}mper, Klaus-Peter and Picard, Antoni and Brill, Manfred and Cassel, Detlev and Jentsch, Andreas and Merten, Sabine and Rollwa, Markus}, title = {The Virtual Clean Room - a new tool in teaching MST process technologies}, year = {2003}, abstract = {The Virtual Clean Room - a new tool in teaching MST process technologies University education in high-technology fields like MST is not complete without intensive laboratory sessions. Students cannot fully grasp the complexity and the special problems related to the manufacturing of microsystems without a thorough hands-on experience in a MST clean room.}, subject = {Virtuelle Maschine}, language = {en} } @article{SeiblerZevnikKueterLuksetal.2003, author = {Seibler, Jost and Zevnik, Branko and K{\"u}ter-Luks, Birgit and Andreas, Susanne and Kern, Heidrun and Hennek, Thomas and Rode, Anja and Heimann, Cornelia and Faust, Nicole and Kauselmann, Gunther and Schoor, Michael and Jaenisch, Rudolf and Rajewsky, Klaus and K{\"u}hn, Ralf and Schwenk, Frieder}, title = {Rapid generation of inducible mouse mutants}, series = {Nucleic Acids Research}, volume = {33}, journal = {Nucleic Acids Research}, number = {4}, issn = {1362-4962}, doi = {10.1093/nar/gng012}, pages = {e12}, year = {2003}, language = {en} } @inproceedings{ChudobaButenwegPfeiffer2003, author = {Chudoba, Rostislav and Butenweg, Christoph and Pfeiffer, Frank}, title = {Textile reinforced concrete. Part I: Process model for collaborative research and development}, series = {Digital proceedings / IKM 2003, proceedings 16th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering [Elektronische Ressource : 10. - 12. Juni 2003, Weimar] / Bauhaus-Universit{\"a}t Weimar. Ed.: K. G{\"u}rlebeck; L. Hempel; C. K{\"o}nke}, booktitle = {Digital proceedings / IKM 2003, proceedings 16th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering [Elektronische Ressource : 10. - 12. Juni 2003, Weimar] / Bauhaus-Universit{\"a}t Weimar. Ed.: K. G{\"u}rlebeck; L. Hempel; C. K{\"o}nke}, publisher = {IKM}, address = {Weimar}, organization = {Internationales Kolloquium {\"u}ber Anwendungen der Informatik und Mathematik in Architektur und Bauwesen <16, 2003, Weimar>}, pages = {1 -- 8}, year = {2003}, language = {en} } @inproceedings{KonradChudobaButenwegetal.2003, author = {Konrad, M. and Chudoba, Rostislav and Butenweg, Christoph and Bruckermann, O.}, title = {Textile reinforced concrete. Part II: Multi-level modeling concept}, series = {Digital proceedings / IKM 2003, proceedings 16th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering [Elektronische Ressource : 10. - 12. Juni 2003, Weimar] / Bauhaus-Universit{\"a}t Weimar. Ed.: K. G{\"u}rlebeck; L. Hempel; C. K{\"o}nke}, booktitle = {Digital proceedings / IKM 2003, proceedings 16th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering [Elektronische Ressource : 10. - 12. Juni 2003, Weimar] / Bauhaus-Universit{\"a}t Weimar. Ed.: K. G{\"u}rlebeck; L. Hempel; C. K{\"o}nke}, publisher = {IKM}, address = {Weimar}, organization = {Internationales Kolloquium {\"u}ber Anwendungen der Informatik und Mathematik in Architektur und Bauwesen <16, 2003, Weimar>}, pages = {1 -- 11}, year = {2003}, language = {en} } @inproceedings{ButenwegKuhlmannLopezetal.2003, author = {Butenweg, Christoph and Kuhlmann, Winfried and Lopez, M. and Fernandez, S.}, title = {Seismic vulnerability assessment of the Aachen Cathedral based on measurements and numerical simulations}, series = {International Conference on Earthquake Engineering to mark 40 years from Catastrophic 1963 Skopje Earthquake, Skopje 2003}, booktitle = {International Conference on Earthquake Engineering to mark 40 years from Catastrophic 1963 Skopje Earthquake, Skopje 2003}, organization = {International conference in earthquake engineering to mark 40 years from catastrophic 1963 Skopje earthquake <2003, Skopje>}, pages = {1 -- 8}, year = {2003}, language = {en} } @incollection{StaatHeitzer2003, author = {Staat, Manfred and Heitzer, Michael}, title = {Probabilistic limit and shakedown problems}, series = {Numerical methods for limit and shakedown analysis. Deterministic and probabilistic problems}, volume = {15}, booktitle = {Numerical methods for limit and shakedown analysis. Deterministic and probabilistic problems}, editor = {Staat, Manfred and Heitzer, Michael}, publisher = {John von Neumann Institute for Computing (NIC)}, address = {J{\"u}lich}, isbn = {3-00-010001-6}, pages = {217 -- 268}, year = {2003}, language = {en} } @article{KearneyHerrmannNavaetal.2003, author = {Kearney, D. and Herrmann, Ulf and Nava, P. and Kelly, B. and Mahoney, R. and Pacheco, J. and Cable, R. and Potrovitza, N. and Blake, D. and Price, H.}, title = {Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field}, series = {Journal of Solar Energy Engineering}, volume = {125}, journal = {Journal of Solar Energy Engineering}, number = {2}, issn = {1528-8986}, doi = {10.1115/1.1565087}, pages = {170 -- 176}, year = {2003}, language = {en} } @book{StaatHeitzer2003, author = {Staat, Manfred and Heitzer, Michael}, title = {Numerical methods for limit and shakedown analysis. Deterministic and probabilistic problems.}, publisher = {John von Neumann Institute for Computing (NIC)}, address = {J{\"u}lich}, isbn = {3-00-010001-6}, pages = {2, xiii, 282 Seiten}, year = {2003}, 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} }