@inproceedings{DachwaldKahleWie2006, author = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong}, title = {Solar sail Kinetic Energy Impactor (KEI) mission design tradeoffs for impacting and deflecting asteroid 99942 Apophis}, series = {AIAA/AAS Astrodynamics Specialist Conference and Exhibit}, booktitle = {AIAA/AAS Astrodynamics Specialist Conference and Exhibit}, doi = {10.2514/6.2006-6178}, pages = {1 -- 20}, year = {2006}, abstract = {Near-Earth asteroid 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several so-called gravitational keyholes during its 2029-encounter. Several pre-2029-deflection scenarios to prevent Apophis from doing this have been investigated so far. Because the keyholes are less than 1 km in size, a pre-2029 kinetic impact is clearly the best option because it requires only a small change in Apophis' orbit to nudge it out of a keyhole. A single solar sail Kinetic Energy Impactor (KEI) spacecraft that impacts Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages at about 0.75 AU would be a feasible option to do this. The spacecraft consists of a 160 m x 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. In this paper, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, solar sail Kinetic Energy Impactor (KEI) spacecraft are still a feasible option to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value. In this paper, we elaborate potential pre- and post-2029 KEI impact scenarios for a launch in 2020, and investigate tradeoffs between different mission parameters.}, language = {en} } @article{DachwaldKahleWie2006, author = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong}, title = {Solar Sailing Kinetic Energy Impactor (KEI) Mission Design Tradeoffs for Impacting and Deflecting Asteroid 99942 Apophis}, series = {AIAA Guidance, Navigation, and Control Conference \& Exhibit - AIAA Atmospheric Flight Mechanics Conference \& Exhibit - AIAA Modeling and Simulation Technologies Conference \& Exhibit - AIAA/AAS Astrodynamics Specialist Conference \& Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )}, journal = {AIAA Guidance, Navigation, and Control Conference \& Exhibit - AIAA Atmospheric Flight Mechanics Conference \& Exhibit - AIAA Modeling and Simulation Technologies Conference \& Exhibit - AIAA/AAS Astrodynamics Specialist Conference \& Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )}, publisher = {American Institute of Aeronautics and Astronautics}, address = {Reston, Va.}, isbn = {1-56347-802-1}, pages = {1 -- 20}, year = {2006}, language = {en} } @article{DachwaldMengaliQuartaetal.2006, author = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandrao A. and Macdonald, Malcolm}, title = {Parametric Model and Optimal Control of Solar Sails with Optical Degradation}, series = {Journal of guidance, control, and dynamics. 29 (2006), H. 5}, journal = {Journal of guidance, control, and dynamics. 29 (2006), H. 5}, isbn = {0162-3192}, pages = {1170 -- 1178}, year = {2006}, language = {en} } @inproceedings{LoebSchartnerSeboldtetal.2006, author = {Loeb, Horst W. and Schartner, Karl-Heinz and Seboldt, Wolfgang and Dachwald, Bernd and Streppel, Joern and Meusemann, Hans and Sch{\"u}lke, Peter}, title = {SEP for a lander mission to the jovian moon europa}, series = {57th International Astronautical Congress}, booktitle = {57th International Astronautical Congress}, doi = {10.2514/6.IAC-06-C4.4.04}, pages = {1 -- 12}, year = {2006}, abstract = {Under DLR-contract, Giessen University and DLR Cologne are studying solar-electric propulsion missions (SEP) to the outer regions of the solar system. The most challenging reference mission concerns the transport of a 1.35-tons chemical lander spacecraft into an 80-RJ circular orbit around Jupiter, which would enable to place a 375 kg lander with 50 kg of scientific instruments on the surface of the icy moon "Europa". Thorough analyses show that the best solution in terms of SEP launch mass times thrusting time would be a two-stage EP module and a triple-junction solar array with concentrators which would be deployed step by step. Mission performance optimizations suggest to propel the spacecraft in the first EP stage by 6 gridded ion thrusters, running at 4.0 kV of beam voltage, which would save launch mass, and in the second stage by 4 thrusters with 1.25 to 1.5 kV of positive high voltage saving thrusting time. In this way, the launch mass of the spacecraft would be kept within 5.3 tons. Without a launcher's C3 and interplanetary gravity assists, Jupiter might be reached within about 4 yrs. The spiraling-down into the parking orbit would need another 1.8 yrs. This "large mission" can be scaled down to a smaller one, e.g., by halving all masses, the solar array power, and the number of thrusters. Due to their reliability, long lifetime and easy control, RIT-22 engines have been chosen for mission analysis. Based on precise tests, the thruster performance has been modeled.}, language = {en} } @inproceedings{KorschDafnisReimerdesetal.2006, author = {Korsch, Helge and Dafnis, Athanasios and Reimerdes, Hans-G{\"u}nther and Braun, Carsten and Ballmann, Josef}, title = {Dynamic qualification of the HIRENASD elastic wing model}, series = {Motto: Luft- und Raumfahrt: Lehre, Forschung, Industrie - gemeinsam innovativ. Deutscher Luft- und Raumfahrtkongress 2006 : Braunschweig, 06. bis 09. November 2006. Jahrbuch / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt. 2006}, booktitle = {Motto: Luft- und Raumfahrt: Lehre, Forschung, Industrie - gemeinsam innovativ. Deutscher Luft- und Raumfahrtkongress 2006 : Braunschweig, 06. bis 09. November 2006. Jahrbuch / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt. 2006}, publisher = {Dt. Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth (DGLR)}, address = {Bonn}, pages = {1441 -- 1450}, year = {2006}, language = {en} } @misc{RainerRoestelWahle2006, author = {Rainer, N{\"a}hle and R{\"o}stel, Reinhard and Wahle, Michael}, title = {Lagerungssystem in einem Raumfahrzeug : Patentschrift}, publisher = {Deutsches Patent- und Markenamt}, address = {M{\"u}nchen}, pages = {7 S.: graph. Darst.}, year = {2006}, language = {de} } @misc{PischingerEschDuesmann2006, author = {Pischinger, Martin and Esch, Thomas and Duesmann, Klaus}, title = {Elektromagnetischer Aktuator mit gelenkig abgest{\"u}tzter R{\"u}ckstellfeder}, year = {2006}, abstract = {Die Erfindung betrifft einen elektromagnetischen Aktuator zur Bet{\"a}tigung eines Stellgliedes (7) mit wenigstens einem gesteuert bestrombaren Elektromagneten (1, 2) und einem mit dem Stellglied (7) in Wirkverbindung stehenden Anker (5), der bei Bestromung des Elektromagneten (1, 2) gegen die Kraft wenigstens einer an einem Geh{\"a}use (12) abgest{\"u}tzten R{\"u}ckstellfeder (10) an der Polfl{\"a}che (3, 4) des Elektromagneten (1, 2) zur Anlage kommt, und daß zumindest der Anker (5) {\"u}ber eine sph{\"a}rische Gelenkanordnung (11) auf der R{\"u}ckstellfeder (10) abgest{\"u}tzt ist.}, language = {de} } @inproceedings{HuthElsenHartwigetal.2006, author = {Huth, Thomas and Elsen, Olaf and Hartwig, Christoph and Esch, Thomas}, title = {Innovative modular valve trains for 2015 - logistic benefits by EMVT}, series = {IFAC Proceedings Volumes, Volume 39, Issue 3}, booktitle = {IFAC Proceedings Volumes, Volume 39, Issue 3}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.3182/20060517-3-FR-2903.00172}, pages = {315 -- 320}, year = {2006}, abstract = {In this paper the way to a 5-day-car with respect to a modular valve train systems for spark ignited combustion engines is shown. The necessary product diversity is shift from mechanical or physical components to software components. Therefore, significant improvements of logistic indicators are expected and shown. The working principle of a camless cylinder head with respect to an electromagnetical valve train (EMVT) is explained and it is demonstrated that shifting physical diversity to software is feasible. The future design of combustion engine systems including customisation can be supported by a set of assistance tools which is shown exemplary.}, language = {en} } @article{BecretGrossenTrillaetal.2007, author = {B{\´e}cret, P. and Grossen, J. and Trilla, J. and Robinson, A. and Bosschaerts, W. and Funke, Harald and Hendrick, P.}, title = {Testing and numerical study of a 10 kW hydrogen micro combustor}, series = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, journal = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, pages = {367 -- 370}, year = {2007}, language = {en} } @article{RobinsonRoennaFunke2007, author = {Robinson, A. E. and R{\"o}nna, Uwe and Funke, Harald}, title = {Testing of a 10 kW diffusive micro-mix combustor for hydrogen-fuelled micro-scale gas turbines}, series = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, journal = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, pages = {225 -- 228}, year = {2007}, language = {en} } @article{FunkeRobinson2007, author = {Funke, Harald and Robinson, A. E.}, title = {Development of a new test rig for a micro scale hydrogen combustion chamber}, series = {Proceedings of the 2nd European Conference for Aero-Space Sciences : July 1 - 6, 2007, Brussels, Belgium}, journal = {Proceedings of the 2nd European Conference for Aero-Space Sciences : July 1 - 6, 2007, Brussels, Belgium}, publisher = {-}, pages = {1 -- 8}, year = {2007}, language = {en} } @article{McArdellBarteltKowalski2007, author = {McArdell, Brian W. and Bartelt, Perry and Kowalski, Julia}, title = {Field observations of basal forces and fluid pore pressure in a debris flow}, series = {Geophysical Research Letters (GRL)}, volume = {34}, journal = {Geophysical Research Letters (GRL)}, number = {7}, isbn = {0094-8276}, year = {2007}, abstract = {Using results from an 8 m2 instrumented force plate we describe field measurements of normal and shear stresses, and fluid pore pressure for a debris flow. The flow depth increased from 0.1 to 1 m within the first 12 s of flow front arrival, remained relatively constant until 100 s, and then gradually decreased to 0.5 m by 600 s. Normal and shear stresses and pore fluid pressure varied in-phase with the flow depth. Calculated bulk densities are ρb = 2000-2250 kg m-3 for the bulk flow and ρf = 1600-1750 kg m-3 for the fluid phase. The ratio of effective normal stress to shear stress yields a Coulomb basal friction angle of ϕ = 26° at the flow front. We did not find a strong correlation between the degree of agitation in the flow, estimated using the signal from a geophone on the force plate, and an assumed dynamic pore fluid pressure. Our data support the idea that excess pore-fluid pressures are long lived in debris flows and therefore contribute to their unusual mobility.}, language = {en} } @inproceedings{KowalskiBarteltMcElwaine2007, author = {Kowalski, Julia and Bartelt, Perry and McElwaine, J.}, title = {Two-phase debris flow modeling}, series = {Geophysical Research Abstracts}, booktitle = {Geophysical Research Abstracts}, year = {2007}, language = {en} } @book{BlomeZaun2007, author = {Blome, Hans-Joachim and Zaun, Harald}, title = {Der Urknall : Anfang und Zukunft des Universums 2., aktualisierte Aufl.}, publisher = {Beck}, address = {M{\"u}nchen}, isbn = {3-406-50837-5}, pages = {128 S.}, year = {2007}, language = {de} } @article{OverduinBlomeHoell2007, author = {Overduin, James and Blome, Hans-Joachim and Hoell, Josef}, title = {Wolfgang Priester: from the big bounce to the Lambda-dominated universe}, series = {Naturwissenschaften}, volume = {94}, journal = {Naturwissenschaften}, number = {6}, isbn = {0028-1042}, pages = {417 -- 429}, year = {2007}, language = {en} } @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} } @article{WittmannBibringRosenbaueretal.2007, author = {Wittmann, Klaus and Bibring, J.-P. and Rosenbauer, H. and Boehnhardt, H.}, title = {The Rosetta Lander ("Philae") Investigations / Bibring, J.-P. ; Rosenbauer, H. ; Boehnhardt, H. ; [...] Wittmann, K.}, series = {Space Science Reviews. 128 (2007), H. 1-4}, journal = {Space Science Reviews. 128 (2007), H. 1-4}, isbn = {0038-6308}, pages = {205 -- 220}, year = {2007}, language = {en} } @book{Esch2007, author = {Esch, Thomas}, title = {Verbrennungstechnik. - 6. Aufl., [Umdruck]. - (Angewandte Thermodynamik und Verbrennungstechnik)}, publisher = {Fachhochschule Aachen, Lehr- und Forschungsgebiet Thermodynamik und Verbrennungstechnik}, address = {Aachen}, pages = {Getr. Z{\"a}hlung : Ill. und graph. Darst.}, year = {2007}, language = {de} } @article{GerhardtSchoenwaldKonrath2007, author = {Gerhardt, Hans Joachim and Sch{\"o}nwald, J. and Konrath, B.}, title = {Verwendung von Leichtgas bei Brandsimulationen - unzul{\"a}ssig oder sinnvoll?}, series = {VFDB-Zeitschrift : Forschung, Technik und Management im Brandschutz. 56 (2007), H. 1}, journal = {VFDB-Zeitschrift : Forschung, Technik und Management im Brandschutz. 56 (2007), H. 1}, isbn = {0042-1804}, pages = {29 -- 31}, year = {2007}, language = {de} } @book{Esch2007, author = {Esch, Thomas}, title = {Experimentelle Untersuchungen an Antriebssystemen von Kraft-, Luft- und Raumfahrzeugen : Vorlesungsumdruck. Bd. 1}, publisher = {Fachhochschule Aachen, Lehr- und Forschungsgebiet Thermodynamik und Verbrennungstechnik}, address = {Aachen}, pages = {Getr. Z{\"a}hlung : zahlr. Ill. und graph. Darst.}, year = {2007}, language = {de} }