TY - CHAP A1 - Seboldt, Wolfgang A1 - Dachwald, Bernd T1 - Solar sails for near-term advanced scientific deep space missions T2 - Proceedings of the 8th International Workshop on Combustion and Propulsion N2 - 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. KW - solar sail KW - low-thrust KW - near-Earth asteroid KW - sample return KW - solar system Y1 - 2003 N1 - Proceedings of the 8th International Workshop on Combustion and Propulsion. Pozzuoli, Italy, 16 - 21 June 2002. ER - TY - CHAP A1 - Grundmann, Jan Thimo A1 - Bauer, Wlademar A1 - Borchers, Kai A1 - Dumont, Etienne A1 - Grimm, Christian D. A1 - Ho, Tra-Mi A1 - Jahnke, Rico A1 - Koch, Aaron D. A1 - Lange, Caroline A1 - Maiwald, Volker A1 - Meß, Jan-Gerd A1 - Mikulz, Eugen A1 - Quantius, Dominik A1 - Reershemius, Siebo A1 - Renger, Thomas A1 - Sasaki, Kaname A1 - Seefeldt, Patric A1 - Spietz, Peter A1 - Spröwitz, Tom A1 - Sznajder, Maciej A1 - Toth, Norbert A1 - Ceriotti, Matteo A1 - McInnes, Colin A1 - Peloni, Alessandro A1 - Biele, Jens A1 - Krause, Christian A1 - Dachwald, Bernd A1 - Hercik, David A1 - Lichtenheldt, Roy A1 - Wolff, Friederike A1 - Koncz, Alexander A1 - Pelivan, Ivanka A1 - Schmitz, Nicole A1 - Boden, Ralf A1 - Riemann, Johannes A1 - Seboldt, Wolfgang A1 - Wejmo, Elisabet A1 - Ziach, Christian A1 - Mikschl, Tobias A1 - Montenegro, Sergio A1 - Ruffer, Michael A1 - Cordero, Federico A1 - Tardivel, Simon T1 - Solar sails for planetary defense & high-energy missions T2 - IEEE Aerospace Conference Proceedings N2 - 20 years after the successful ground deployment test of a (20 m) 2 solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and hardware design studies as well as the hardware built in the course of our solar sail technology development. We outline the most likely and most efficient routes to develop solar sails for useful missions in science and applications, based on our developed `now-term' and near-term hardware as well as the many practical and managerial lessons learned from the DLR-ESTEC Gossamer Roadmap. Mission types directly applicable to planetary defense include single and Multiple NEA Rendezvous ((M)NR) for precursor, monitoring and follow-up scenarios as well as sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation. Other mission types such as the Displaced L1 (DL1) space weather advance warning and monitoring or Solar Polar Orbiter (SPO) types demonstrate the capability of near-term solar sails to achieve asteroid rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. Some of these mission types such as SPO, (M)NR and RKI include separable payloads. For one-way access to the asteroid surface, nanolanders like MASCOT are an ideal match for solar sails in micro-spacecraft format, i.e. in launch configurations compatible with ESPA and ASAP secondary payload platforms. Larger landers similar to the JAXA-DLR study of a Jupiter Trojan asteroid lander for the OKEANOS mission can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. The high impact velocities and re-try capability achieved by the RKI mission type on a final orbit identical to the target asteroid's but retrograde to its motion enables small spacecraft size impactors to carry sufficient kinetic energy for deflection. Y1 - 2019 U6 - https://doi.org/10.1109/AERO.2019.8741900 N1 - AERO 2019; Big Sky; United States; 2 March 2019 through 9 March 2019 SP - 1 EP - 21 ER - TY - CHAP A1 - Konstantinidis, K. A1 - Kowalski, Julia A1 - Martinez, C. F. A1 - Dachwald, Bernd A1 - Ewerhart, D. A1 - Förstner, R. T1 - Some necessary technologies for in-situ astrobiology on enceladus T2 - Proceedings of the International Astronautical Congress Y1 - 2015 SN - 978-151081893-4 N1 - 6th International Astronautical Congress 2015: Space - The Gateway for Mankind's Future, IAC 2015; Jerusalem; Israel; 12 October 2015 through 16 October 2015 SP - 1354 EP - 1372 ER - TY - CHAP A1 - Digel, Ilya A1 - Temiz Artmann, Aysegül A1 - Nojima, H. A1 - Artmann, Gerhard T1 - Some peculiarities of application of cluster ions generated by plasma in respect of indoor air purification :[abstract] N2 - Recently, the SHARP Corporation, Japan, has developed the world’s first "Plasma Cluster Ions (PCI)" air purification technology using plasma discharge to generate cluster ions. The new plasma cluster device releases positive and negative ions into the air, which are able to decompose and deactivate harmful airborne substances by chemical reactions. Because cluster ions consist of positive and negative ions that normally exist in the natural world, they are completely harmless and safe to humans. The amount of ozone generated by cluster ions is less than 0.01 ppm, which is significantly less than the 0.05-ppm standard for industrial operations and consumer electronics. This amount, thus, has no harming effects whatsoever on the human body. But particular properties and chemical processes in PCI treatment are still under study. It has been shown that PCI in most cases show strongly pronounced irreversible killing effects in respect of airborne microflora due to free-radical induced reactions and can be considered as a potent technology to disinfect both home, medical and industrial appliances. KW - Clusterion KW - Raumluft KW - Luftreiniger KW - Plasmacluster ion technology KW - Air purification Y1 - 2003 ER - TY - CHAP A1 - Staat, Manfred A1 - Tran, Ngoc Trinh T1 - Strain based brittle failure criteria for rocks T2 - Proceedings of (NACOME2022) The 11th National Conference on Mechanics, Vol. 1. Solid Mechanics, Rock Mechanics, Artificial Intelligence, Teaching and Training N2 - When confining pressure is low or absent, extensional fractures are typical, with fractures occurring on unloaded planes in rock. These “paradox” fractures can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. But this criterion makes unrealistic strength predictions in biaxial compression and tension. A new extension strain criterion overcomes this limitation by adding a weighted principal shear component. The weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr–Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting failure modes, which are unexpected in the understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak P. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion. KW - Extension fracture KW - Extension strain criterion KW - Mohr–Coulomb criterion KW - Evolution of damage Y1 - 2023 SN - 978-604-357-084-7 N1 - 11th National Conference on Mechanics (NACOME 2022), December 2-3, 2022, VNU University of Engineering and Technology, Hanoi, Vietnam SP - 500 EP - 509 PB - Nha xuat ban Khoa hoc tu nhien va Cong nghe (Verlag Naturwissenschaft und Technik) CY - Hanoi ER - TY - CHAP A1 - Stadler, Andreas M. A1 - Embs, Jan P. A1 - Zerlin, Kay A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Zaccai, Joe A1 - Büldt, Georg T1 - Temperature transitions of hemoglobin and cytosolic water diffusion in human red blood cells : [poster] N2 - Background Hemoglobin interactions in red blood cells Hemoglobin dynamics in human red blood cells Diffusion of H2O in red blood cells KW - Erythrozyt KW - Hämoglobin KW - cytosolic water diffusion KW - hemoglobin dynamics Y1 - 2007 ER - TY - CHAP A1 - Artmann, Gerhard A1 - Stadler, Andreas M. A1 - Embs, Jan P. A1 - Zaccai, Giuseppe A1 - Büldt, Georg A1 - Digel, Ilya A1 - Temiz Artmann, Aysegül T1 - The crucial role of water in a phase transition of hemoglobin at body temperature : [abstract] N2 - The observation of a temperature transition of hemoglobin occurring at a critical temperature close to body temperature KW - Hämoglobin KW - Erythrozyt KW - Körpertemperatur Y1 - 2010 ER - TY - CHAP A1 - Duprat, J. A1 - Dachwald, Bernd A1 - Hilchenbach, M. A1 - Engrand, Cecile A1 - Espe, C. A1 - Feldmann, M. A1 - Francke, G. A1 - Görög, Mark A1 - Lüsing, N. A1 - Langenhorst, Falko T1 - The MARVIN project: a micrometeorite harvester in Antarctic snow T2 - 44th Lunar and Planetary Science Conference N2 - MARVIN is an automated drilling and melting probe dedicated to collect pristine interplanetary dust particles (micrometeorites) from central Antarctica snow. Y1 - 2013 N1 - 44th Lunar and Planetary Science Conference, March 18-22, 2013, The Woodlands, Texas ER - TY - CHAP A1 - Staat, Manfred A1 - Heitzer, Michael T1 - The restricted influence of kinematic hardening on shakedown loads N2 - Structural design analyses are conducted with the aim of verifying the exclusion of ratcheting. To this end it is important to make a clear distinction between the shakedown range and the ratcheting range. In cyclic plasticity more sophisticated hardening models have been suggested in order to model the strain evolution observed in ratcheting experiments. The hardening models used in shakedown analysis are comparatively simple. It is shown that shakedown analysis can make quite stable predictions of admissible load ranges despite the simplicity of the underlying hardening models. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis. Both give identical or similar shakedown ranges. Structural shakedown analyses show that the loading may have a more pronounced effect than the hardening model. KW - Biomedizinische Technik KW - Einspielen KW - Shakedown KW - Ratcheting KW - Bruchmechanik KW - shakedown KW - material shakedown KW - linear kinematic hardening KW - nonlinear kinematic hardening KW - ratchetting Y1 - 2002 ER - TY - CHAP A1 - Jean-Pierre P., de Vera A1 - Baque, Mickael A1 - Billi, Daniela A1 - Böttger, Ute A1 - Bulat, Sergey A1 - Czupalla, Markus A1 - Dachwald, Bernd A1 - de la Torre, Rosa A1 - Elsaesser, Andreas A1 - Foucher, Frédéric A1 - Korsitzky, Hartmut A1 - Kozyrovska, Natalia A1 - Läufer, Andreas A1 - Moeller, Ralf A1 - Olsson-Francis, Karen A1 - Onofri, Silvano A1 - Sommer, Stefan A1 - Wagner, Dirk A1 - Westall, Frances T1 - The search for life on Mars and in the Solar System - strategies, logistics and infrastructures T2 - 69th International Astronautical Congress (IAC) N2 - The question "Are we alone in the Universe?" is perhaps the most fundamental one that affects mankind. How can we address the search for life in our Solar System? Mars, Enceladus and Europa are the focus of the search for life outside the terrestrial biosphere. While it is more likely to find remnants of life (fossils of extinct life) on Mars because of its past short time window of the surface habitability, it is probably more likely to find traces of extant life on the icy moons and ocean worlds of Jupiter and Saturn. Nevertheless, even on Mars there could still be a chance to find extant life in niches near to the surface or in just discovered subglacial lakes beneath the South Pole ice cap. Here, the different approaches for the detection of traces of life in the form of biosignatures including pre-biotic molecules will be presented. We will outline the required infrastructure for this enterprise and give examples of future mission concepts to investigate the presence of life on other planets and moons. Finally, we will provide suggestions on methods, techniques, operations and strategies for preparation and realization of future life detection missions. KW - life detection KW - Mars KW - icy moons KW - habitability KW - space missions Y1 - 2018 N1 - 69th International Astronautical Congress (IAC), Bremen, Germany, 1-5 October 2018. SP - 1 EP - 8 ER -