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  - Staat, Manfred
A1  - Heitzer, M.
A1  - Lang, H.
A1  - Wirtz, K.
T1  - Direct Finite Element Route for Design-by-Analysis of Pressure Components
JF  - International Journal of Pressure Vessels and Piping. 82 (2005), H. 1
Y1  - 2005
SN  - 0308-0161
SP  - 61
EP  - 67
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels
JF  - International Journal of Pressure Vessels and Piping. 82 (2005), H. 3
Y1  - 2005
SN  - 0308-0161
SP  - 217
EP  - 225
ER  - 
TY  - JOUR
A1  - Temiz Artmann, Aysegül
A1  - Linder, Peter
A1  - Kayser, Peter
A1  - Digel, Ilya
T1  - NMR in vitro effects on proliferation, apoptosis, and viability of human chondrocytes and osteoblasts
JF  - Methods and findings in Experimental and Clinical Pharmacology. 27 (2005), H. 6
Y1  - 2005
SN  - 0379-0355
SP  - 391
EP  - 394
ER  - 
TY  - JOUR
A1  - Temiz Artmann, Aysegül
A1  - Kayatekin, Muammer B.
A1  - Uysal, N.
A1  - Resmi, H.
T1  - Does antioxidant supplementation alter the effects of acute exercise on erythrocyte aggregation, deformability and endothelium adhesion in untrained rats? Kayatekin, Muammer B.; Uysal N.; Resmi, H.; Bediz, Seref C.; Temiz Artmann, A.; Genç, S.; Tugyan, K.
JF  - International Journal for Vitamin and Nutrition Research. 75 (2005), H. 4
Y1  - 2005
SN  - 0300-9831
SP  - 243
EP  - 250
ER  - 
TY  - JOUR
A1  - Temiz Artmann, Aysegül
A1  - Resmi, Halil
A1  - Akhunlar, Hülya
A1  - Güner, Gül
T1  - In vitro effects of high glucose concentrations on membrane protein sulfhydryl oxidation, G-actin and deformability of human erythrocytes. Resmi, Halil ; Akhunlar, Hülya ; Temiz Artmann, Aysegül ; Güner, Gül
JF  - Cell biochemistry and function. 23 (2005), H. 3
Y1  - 2005
SN  - 0263-6484
SP  - 163
EP  - 168
ER  - 
TY  - JOUR
A1  - Temiz Artmann, Aysegül
A1  - Akhisaroglu, M.
A1  - Sercan, Z.
A1  - Kayatekin, B. M.
T1  - Adhesion of Erythrocytes to Endothelial Cells After Acute Exercise: Differences in Red Blood Cells from Juvenile and Adult Rats. Temiz Artmann, A.; Akhisaroglu, M.; Sercan, Z.; Kayatekin, BM.; Yorukoglu, K.; Kirkali, G.
JF  - Physiological  Research (2005)
Y1  - 2005
SN  - 0862-8408
N1  - pre-press article
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Multiple Near-Earth Asteroid Rendezvous and Sample Return Using First Generation Solar Sailcraft
JF  - Acta Astronautica. 57 (2005), H. 11
Y1  - 2005
SN  - 0094-5765
SP  - 864
EP  - 875
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of very-low-thrust trajectories using evolutionary neurocontrol
JF  - Acta Astronautica. 57 (2005), H. 2-8
Y1  - 2005
SN  - 0094-5765
SP  - 175
EP  - 185
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimal Solar Sail Trajectories for Missions to the Outer Solar System
JF  - Journal of guidance, control, and dynamics. 28 (2005), H. 6
Y1  - 2005
SN  - 0162-3192
N1  - 2. ISSN: 0162-3192. - 3. ISSN: 0731-5090
SP  - 1187
EP  - 1193
ER  -