TY - CHAP A1 - Dachwald, Bernd A1 - Kahle, Ralph A1 - Wie, Bong T1 - Solar sail Kinetic Energy Impactor (KEI) mission design tradeoffs for impacting and deflecting asteroid 99942 Apophis T2 - AIAA/AAS Astrodynamics Specialist Conference and Exhibit N2 - 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. KW - Solar Sail KW - Asteroid Deflection KW - Planetary Protection KW - Trajectory Optimization Y1 - 2006 U6 - http://dx.doi.org/10.2514/6.2006-6178 N1 - AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 21 August 2006 - 24 August 2006, Keystone, Colorado(USA). SP - 1 EP - 20 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Mengali, Giovanni A1 - Quarta, Alessandrao A. A1 - Macdonald, Malcolm T1 - Parametric Model and Optimal Control of Solar Sails with Optical Degradation JF - Journal of guidance, control, and dynamics. 29 (2006), H. 5 Y1 - 2006 SN - 0162-3192 N1 - 2. ISSN: 0731-5090 SP - 1170 EP - 1178 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Ohndorf, A. A1 - Wie, Bong T1 - Solar Sail Trajectory Optimization for the Solar Polar Imager (SPI) Mission JF - 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 ) Y1 - 2006 SN - 1-56347-802-1 N1 - American Institute of Aeronautics and Astronautics ; American Astronautical Society ; AIAA/AAS Astrodynamics Specialist Conference & Exhibit <2006, Keystone, Colo.> ; AIAA paper number: AIAA-2006-6177 PB - American Institute of Aeronautics and Astronautics CY - Reston, Va. ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, W. A1 - Richter, L. T1 - Multiple rendezvous and sample return missions to near-Earth objects using solar sailcraft / Dachwald, B. ; Seboldt, W. ; Richter, L. JF - Acta Astronautica. 59 (2006), H. 8-11 Y1 - 2006 SN - 0094-5765 N1 - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; Selected Proceedings SP - 768 EP - 776 ER - TY - JOUR A1 - Dethloff, Nina A1 - Kroll-Ludwigs, Kathrin T1 - The Constitutional Court as Driver of Reforms in German Family Law JF - International Survey of Family Law Y1 - 2018 SP - 217 EP - 234 ER - TY - JOUR A1 - Digel, Ilya A1 - Maggakis-Kelemen, Christina A1 - Zerlin, Kay A1 - Linder, Peter T1 - Body temperature-related structural transitions of monotremal and human hemoglobin JF - Biophysical Journal. 91 (2006), H. 8 Y1 - 2006 SN - 1542-0086 SP - 3014 EP - 3021 ER - TY - JOUR A1 - Dikta, Gerhard T1 - Time series methods to forecast patent filings JF - Forecasting innovations : methods for predicting numbers of patent filings ; with 71 tables / Peter Hingley ; Marc Nicolas (ed.), Y1 - 2006 SN - 978-3-540-35991-3 U6 - http://dx.doi.org/10.1007/3-540-35992-3_6 N1 - ISBN 3-540-35991-5 SP - 95 EP - 124 PB - Springer CY - Berlin [u.a.] ER - TY - JOUR A1 - Dikta, Gerhard A1 - Kvesic, Marsel A1 - Schmidt, Christian T1 - Bootstrap Approximations in Model Checks for Binary Data JF - Journal of the American Statistical Association. 101 (2006), H. 474 Y1 - 2006 SN - 0162-1459 SP - 521 EP - 530 ER - TY - CHAP A1 - Dilthey, Ulrich A1 - Schleser, Markus ED - Barroso de Aguiar, Jose ED - Jalali, Said ED - Camoes, Aires ED - Ferrera, Rui Miguel T1 - Composite improvement of textile reinforced concrete by polymeric impregnation of the textiles T2 - International Symposium Polymers in Concrete : proceedings of ISPIC 2006, 2-4 April 2006 - University of Minho - Guimarães, Portugal Y1 - 2006 SN - 972-99179-1-4 SP - 185 EP - 192 PB - Universidade do Minho, Departamento de Engenharia Civil CY - Guimarães ER - TY - CHAP A1 - Dilthey, Ulrich A1 - Schleser, Markus A1 - Möller, M. A1 - Weichhold, O. ED - Hegger, Josef T1 - Application of polymers in textile reinforced concrete : from the interface to construction elements T2 - Textile reinforced concrete : proceedings of the 1. International RILEM Conference, held at the RWTH Aachen, September 6/7, 2006. (RILEM proceedings ; 50) Y1 - 2006 SN - 2-912143-97-7 SP - 55 EP - 64 PB - RILEM Publ. CY - Bagneux ER -