@book{Ley1988, author = {Ley, Wilfried}, title = {Handbuch der Raumfahrttechnik : Grundlagen - Nutzung, Raumfahrtsysteme - Produktsicherung u. Produktmanagement / Willi Hallmann; Wilfried Ley}, publisher = {Hanser}, address = {M{\"u}nchen [u.a.]}, isbn = {3446151303}, pages = {XVIII, 792 S : Ill., graph. Darst.}, year = {1988}, language = {de} } @book{Ley1999, author = {Ley, Wilfried}, title = {Raumflugbetrieb : Gemeinschaftsveranstaltung der FH Aachen, der DGLR und der DLR / 12. Raumfahrt-Kolloquium an der Fachhochschule Aachen, 11. November 1999. / Ley Wilfried [Hrsg.]}, publisher = {DGLR}, address = {Bonn}, isbn = {3-932182-07-03}, pages = {VIII, 215 S. : zahlr. Ill., graph. Darst.}, year = {1999}, language = {de} } @book{Ley2000, author = {Ley, Wilfried}, title = {Meteoriten und Space Debris : Gemeinschaftsveranstaltung der FH Aachen, der DGLR und der DLR / 13. Raumfahrt-Kolloquium an der Fachhochschule Aachen, 23. November 2000. / Ley, Wilfried [Hrsg.]}, publisher = {DGLR}, address = {Bonn}, isbn = {3-932182-14-6}, pages = {VIII, 296 S. : zahlr. Ill., graph. Darst.}, year = {2000}, language = {de} } @book{Ley2008, author = {Ley, Wilfried}, title = {Handbuch der Raumfahrttechnik / Ley, Wilfried ; Wittmann, Klaus ; Hallmann, Willi [Hrsg.]}, publisher = {Hanser}, address = {M{\"u}nchen}, isbn = {978-3-446-41185-2}, pages = {814 S. : zahlr. Ill., graph. Darst.}, year = {2008}, language = {de} } @article{LeyPlescherScholzetal.2007, author = {Ley, Wilfried and Plescher, Engelbert and Scholz, Artur and Piepenbrock, Johannes}, title = {COMPASS-1 picosatellite project / Ley, Wilfried ; Plescher, Engelbert ; Scholz, Artur ; Piepenbrock, Johannes}, series = {Small satellites for earth observation : digest of the 6th International symposium of the International Academy of Astronautics, Berlin, April 23 - 26, 2007 / ed. by Rainer Sandau; Hans-Peter R{\"o}ser; Arnoldo Valenzuela}, journal = {Small satellites for earth observation : digest of the 6th International symposium of the International Academy of Astronautics, Berlin, April 23 - 26, 2007 / ed. by Rainer Sandau; Hans-Peter R{\"o}ser; Arnoldo Valenzuela}, publisher = {Wissenschaft und Technik Verl.}, address = {Berlin}, isbn = {9783896855718}, pages = {147 -- 150}, year = {2007}, language = {en} } @book{LeyWittmannHallmann2009, author = {Ley, Wilfried and Wittmann, Klaus and Hallmann, Willi}, title = {Handbook of space technology}, publisher = {Wiley}, address = {Chichester}, isbn = {978-0-470-69739-9}, pages = {XIII, 882 S. : Ill., graph. Darst.}, year = {2009}, language = {en} } @inproceedings{LoebSchartnerDachwaldetal.2011, author = {Loeb, Horst W. and Schartner, Karl-Heinz and Dachwald, Bernd and Ohndorf, Andreas and Seboldt, Wolfgang}, title = {An Interstellar - Heliopause mission using a combination of solar/radioisotope electric propulsion}, series = {Presented at the 32nd International Electric Propulsion Conference}, booktitle = {Presented at the 32nd International Electric Propulsion Conference}, pages = {1 -- 7}, year = {2011}, abstract = {There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft travelling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by ESA.Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope electric propulsion. As a further alternative, we here investigate a combination of solar-electric propulsion and radioisotope-electric propulsion. The solar-electric propulsion stage consists of six 22 cm diameter "RIT-22"ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW BOM is provided by a light-weight solar array. The REP-stage consists of four space-proven 10 cm diameter "RIT-10" ion thrusters that will be operating one after the other for 9 yrs in total. Four advanced radioisotope generators provide 648 W at BOM. The scientific instrument package is oriented at earlier studies. For its mass and electric power requirement 35 kg and 35 W are assessed, respectively. Optimized trajectory calculations, treated in a separate contribution, are based on our "InTrance" method.The program yields a burn out of the REP stage in a distance of 79.6 AU for a usage of 154 kg of Xe propellant. With a C3 = 45,1 (km/s)2 a heliocentric probe velocity of 10 AU/yr is reached at this distance, provided a close Jupiter gravity assist adds a velocity increment of 2.7 AU/yr. A transfer time of 23.8 yrs results for this scenario requiring about 450 kg Xe for the SEP stage, jettisoned at 3 AU. We interpret the SEP/REP propulsion as a competing alternative to solar sail and ballistic/REP propulsion. Omiting a Jupiter fly-by even allows more launch flexibility, leaving the mission duration in the range of the ESA specification.}, language = {en} } @inproceedings{LoebSchartnerSeboldtetal.2006, author = {Loeb, Horst W. and Schartner, Karl-Heinz and Seboldt, Wolfgang and Dachwald, Bernd and Streppel, Joern and Meusemann, Hans and Sch{\"u}lke, Peter}, title = {SEP for a lander mission to the jovian moon europa}, series = {57th International Astronautical Congress}, booktitle = {57th International Astronautical Congress}, doi = {10.2514/6.IAC-06-C4.4.04}, pages = {1 -- 12}, year = {2006}, abstract = {Under DLR-contract, Giessen University and DLR Cologne are studying solar-electric propulsion missions (SEP) to the outer regions of the solar system. The most challenging reference mission concerns the transport of a 1.35-tons chemical lander spacecraft into an 80-RJ circular orbit around Jupiter, which would enable to place a 375 kg lander with 50 kg of scientific instruments on the surface of the icy moon "Europa". Thorough analyses show that the best solution in terms of SEP launch mass times thrusting time would be a two-stage EP module and a triple-junction solar array with concentrators which would be deployed step by step. Mission performance optimizations suggest to propel the spacecraft in the first EP stage by 6 gridded ion thrusters, running at 4.0 kV of beam voltage, which would save launch mass, and in the second stage by 4 thrusters with 1.25 to 1.5 kV of positive high voltage saving thrusting time. In this way, the launch mass of the spacecraft would be kept within 5.3 tons. Without a launcher's C3 and interplanetary gravity assists, Jupiter might be reached within about 4 yrs. The spiraling-down into the parking orbit would need another 1.8 yrs. This "large mission" can be scaled down to a smaller one, e.g., by halving all masses, the solar array power, and the number of thrusters. Due to their reliability, long lifetime and easy control, RIT-22 engines have been chosen for mission analysis. Based on precise tests, the thruster performance has been modeled.}, language = {en} } @article{LoebSchartnerDachwaldetal.2012, author = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Ohndorf, Andreas and Seboldt, Wolfgang}, title = {Interstellar heliopause probe}, series = {Труды МАИ}, journal = {Труды МАИ}, number = {60}, publisher = {Moskauer Staatliches Luftfahrtinstitut (МАИ)}, address = {Moskau}, pages = {2 -- 2}, year = {2012}, abstract = {There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft traveling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by European Space Agency (ESA). Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope-electric propulsion (REP). As a further alternative, we here investigate a combination of solar-electric propulsion (SEP) and REP. The SEP stage consists of six 22-cms diameter RIT-22 ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW at begin of mission (BOM) is provided by a lightweight solar array.}, language = {en} } @inproceedings{LoebSchartnerDachwaldetal.2007, author = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Seboldt, Wolfgang}, title = {SEP-Sample return from a main belt asteroid}, series = {30th International Electric Propulsion Conference}, booktitle = {30th International Electric Propulsion Conference}, pages = {1 -- 11}, year = {2007}, abstract = {By DLR-contact, sample return missions to the large main-belt asteroid "19, Fortuna" have been studied. The mission scenario has been based on three ion thrusters of the RIT-22 model, which is presently under space qualification, and on solar arrays equipped with triple-junction GaAs solar cells. After having designed the spacecraft, the orbit-to-orbit trajectories for both, a one-way SEP mission with a chemical sample return and an all-SEP return mission, have been optimized using a combination of artificial neural networks with evolutionary algorithms. Additionally, body-to-body trajectories have been investigated within a launch period between 2012 and 2015. For orbit-to-orbit calculation, the launch masses of the hybrid mission and of the all-SEP mission resulted in 2.05 tons and 1.56 tons, respectively, including a scientific payload of 246 kg. For the related transfer durations 4.14 yrs and 4.62 yrs were obtained. Finally, a comparison between the mission scenarios based on SEP and on NEP have been carried out favouring clearly SEP.}, language = {en} } @inproceedings{LudowicyRingsFingeretal.2018, author = {Ludowicy, Jonas and Rings, Ren{\´e} and Finger, Felix and Braun, Carsten}, title = {Sizing Studies of Light Aircraft with Serial Hybrid Propulsion Systems}, series = {Luft- und Raumfahrt - Digitalisierung und Vernetzung : Deutscher Luft- und Raumfahrtkongress 2018. 4. - 6. September 2018 - Friedrichshafen}, booktitle = {Luft- und Raumfahrt - Digitalisierung und Vernetzung : Deutscher Luft- und Raumfahrtkongress 2018. 4. - 6. September 2018 - Friedrichshafen}, pages = {11 S.}, year = {2018}, language = {en} } @inproceedings{LudowicyRingsFingeretal.2018, author = {Ludowicy, Jonas and Rings, Ren{\´e} and Finger, Felix and Braun, Carsten}, title = {Sizing Studies of Light Aircraft with Parallel Hybrid Propulsion Systems}, series = {Deutscher Luft- und Raumfahrtkongress 2018}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2018}, doi = {10.25967/480227}, pages = {15 S.}, year = {2018}, language = {en} } @inproceedings{LudowicyRingsFingeretal.2019, author = {Ludowicy, Jonas and Rings, Ren{\´e} and Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Impact of Propulsion Technology Levels on the Sizing and Energy Consumption for Serial HybridElectric General Aviation Aircraft}, series = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, booktitle = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, pages = {14 Seiten}, year = {2019}, language = {en} } @article{LyonsMikuckiGermanetal.2019, author = {Lyons, W. Berry and Mikucki, Jill A. and German, Laura A. and Welch, Kathleen A. and Welch, Susan A. and Gardener, Christopher B. and Tulaczyk, Slawek M. and Pettit, Erin C. and Kowalski, Julia and Dachwald, Bernd}, title = {The Geochemistry of Englacial Brine from Taylor Glacier, Antarctica}, series = {Journal of Geophysical Research: Biogeosciences}, journal = {Journal of Geophysical Research: Biogeosciences}, publisher = {Wiley}, address = {Hoboken}, issn = {2169-8961}, doi = {10.1029/2018JG004411}, year = {2019}, language = {en} } @incollection{MacdonaldMcGrathAppourchauxetal.2014, author = {Macdonald, Malcolm and McGrath, C. and Appourchaux, T. and Dachwald, Bernd and Finsterle, W. and Gizon, L. and Liewer, P. C. and McInnes, Colin R. and Mengali, G. and Seboldt, Wolfgang and Sekii, T. and Solanki, S. K. and Velli, M. and Wimmer-Schweingruber, R. F. and Spietz, Peter and Reinhard, Ruedeger}, title = {Gossamer roadmap technology reference study for a solar polar mission}, series = {Advances in solar sailing}, booktitle = {Advances in solar sailing}, editor = {Macdonald, Malcolm}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {978-3-642-34906-5}, doi = {10.1007/978-3-642-34907-2_17}, pages = {243 -- 257}, year = {2014}, abstract = {A technology reference study for a solar polar mission is presented. The study uses novel analytical methods to quantify the mission design space including the required sail performance to achieve a given solar polar observation angle within a given timeframe and thus to derive mass allocations for the remaining spacecraft sub-systems, that is excluding the solar sail sub-system. A parametric, bottom-up, system mass budget analysis is then used to establish the required sail technology to deliver a range of science payloads, and to establish where such payloads can be delivered to within a given timeframe. It is found that a solar polar mission requires a solar sail of side-length 100-125 m to deliver a 'sufficient value' minimum science payload, and that a 2.5 μm sail film substrate is typically required, however the design is much less sensitive to the boom specific mass.}, language = {en} } @misc{MachadoDahmannKeimeretal.2020, author = {Machado, Patricia Almeida and Dahmann, Peter and Keimer, Jona and Saretzki, Charlotte and St{\"u}bing, Felix and K{\"u}pper, Thomas}, title = {Stress profile and individual workload monitoring in general aviation pilots - an experiment's setting}, series = {23. Annual Meeting of the German Society of Travel Medicine, Coburg, 18.-19.9.2020}, journal = {23. Annual Meeting of the German Society of Travel Medicine, Coburg, 18.-19.9.2020}, doi = {10.55225/hppa.156}, year = {2020}, language = {en} } @misc{MaiwaldDachwald2010, author = {Maiwald, Volker and Dachwald, Bernd}, title = {Mission design for a multiple-rendezvous mission to Jupiter's trojans}, pages = {3}, year = {2010}, abstract = {In this paper, we will provide a feasible mission design for a multiple-rendezvous mission to Jupiter's Trojans. It is based on solar electric propulsion, as being currently used on the DAWN spacecraft, and other flight-proven technology. First, we have selected a set of mission objectives, the prime objective being the detection of water -especially subsurface water -to provide evidence for the Trojans' formation at large solar distances. Based on DAWN and other comparable missions, we have determined suitable payload instruments to achieve these objectives. Afterwards, we have designed a spacecraft that is able to carry the selected payload to the Trojan region and rendezvous successively with three target bodies within a maximum mission duration of 15 years. Accurate low-thrust trajectories have been obtained with a global low-thrust trajectory optimization program (InTrance). During the transfer from Earth to the first target, the spacecraft is propelled by two RIT-22 ion engines from EADS Astrium, whereas a single RIT-15 is used for transfers within the Trojan region to reduce the required power. For power generation, the spacecraft uses a multi-junction solar array that is supported by concentrators. To achieve moderate mission costs, we have restricted the launch mass to a maximum of 1600 kg, the maximum interplanetary injection capability of a Soyuz/Fregat launcher. Our final layout has a mass of 1400 kg, yielding a margin of about 14\%. Nestor (a member of the L4-population) was determined as the first mission target. It can be reached within 4.6 years from launch. The fuel mass ratio for this transfer is about 35\%. The stay time at Nestor is 1.2 years. Eurymedon was selected as the second target (transfer time 3.5 years, stay time 3.0 years) and Irus as the third target (transfer time 2.2 years). The transfers within the Trojan L4-population can be accomplished with fuel mass ratios of about 3\% for each trajectory leg. Including the stay times in orbit around the targets, the mission can be accomplished within a total duration of about 14.5 years. According to our mission analysis, it is also feasible to fly to the L5-population with similar flight times. It has to be noted that -for a first analysis -we have taken only the named targets into account. Allowing also rendezvous with unnamed objects will very likely decrease the mission duration. Based on a scaling of DAWN's mission costs (due to comparable scientific instruments and mission objectives), and taking into account the longer mission duration and the potential re-use of already developed technology, we have estimated that these three rendezvous can be accomplished with a budget of about 250 Million Euros, i.e. about 25\% of ROSETTA's budget.}, language = {en} } @article{MatheisRoethWagner2005, author = {Matheis, Anton and R{\"o}th, Thilo and Wagner, Manfred}, title = {Studentenprojekt "Capro" - eine virtuelle Sportwagenstudie "Vision 2015"}, year = {2005}, abstract = {Design- und Karosseriebaustudenten der FH Aachen entwickeln gemeinsam mit externen Fachleuten unter Einsatz virtueller Entwicklungswerkzeuge ein Konzept f{\"u}r einen Sportwagen}, subject = {Karosseriebau}, language = {de} } @article{MathiakPlescherWillnecker2005, author = {Mathiak, Gerhard and Plescher, Engelbert and Willnecker, Rainer}, title = {Liquid metal diffusion experiments in microgravity - Vibrational effects}, series = {Measurement science and technology}, volume = {Vol. 16}, journal = {Measurement science and technology}, number = {No. 2}, issn = {0957-0233}, doi = {10.1088/0957-0233/16/2/003}, pages = {336}, year = {2005}, language = {en} } @inproceedings{MathiakPlescherWillnecker2003, author = {Mathiak, Gerhard and Plescher, Engelbert and Willnecker, Rainer}, title = {Parabolic flight experiments about vibrational effects on diffusion experiments}, series = {54th International Astronautical Congress of the International Astronautical Federation (IAF) : Bremen, 29 Sept. 2003 through 3 Oct. 2003 ; vol. 1}, booktitle = {54th International Astronautical Congress of the International Astronautical Federation (IAF) : Bremen, 29 Sept. 2003 through 3 Oct. 2003 ; vol. 1}, organization = {International Astronautical Congress of the International Astronautical Federation <54, 2003, Bremen>}, pages = {4389 -- 4396}, year = {2003}, language = {de} }