TY - CHAP A1 - Macdonald, Malcolm A1 - McGrath, C. A1 - Appourchaux, T. A1 - Dachwald, Bernd A1 - Finsterle, W. A1 - Gizon, L. A1 - Liewer, P. C. A1 - McInnes, Colin R. A1 - Mengali, G. A1 - Seboldt, W. A1 - Sekii, T. A1 - Solanki, S. K. A1 - Velli, M. A1 - Wimmer-Schweingruber, R. F. A1 - Spietz, Peter A1 - Reinhard, Ruedeger ED - Macdonald, Malcolm T1 - Gossamer roadmap technology reference study for a solar polar mission T2 - Advances in solar sailing N2 - 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. Y1 - 2014 SN - 978-3-642-34906-5 U6 - http://dx.doi.org/10.1007/978-3-642-34907-2_17 SP - 243 EP - 257 PB - Springer CY - Berlin, Heidelberg ER - TY - JOUR A1 - Dachwald, Bernd A1 - Mikucki, Jill A1 - Tulaczyk, Slawek A1 - Digel, Ilya A1 - Espe, Clemens A1 - Feldmann, Marco A1 - Francke, Gero A1 - Kowalski, Julia A1 - Xu, Changsheng T1 - IceMole : A maneuverable probe for clean in situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems JF - Annals of Glaciology N2 - There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample. KW - Antarctic Glaciology KW - Extraterrestrial Glaciology KW - Glaciological instruments and methods KW - Subclacial exploration KW - Subglacial lakes Y1 - 2014 U6 - http://dx.doi.org/10.3189/2014AoG65A004 SN - 1727-5644 VL - 55 IS - 65 SP - 14 EP - 22 PB - Cambridge University Press CY - Cambridge ER - TY - CHAP A1 - Dachwald, Bernd A1 - Ulamec, Stephan A1 - Biele, Jens T1 - Clean in situ subsurface exploration of icy environments in the solar system T2 - Habitability of other planets and satellites. - (Cellular origin, life in extreme habitats and astrobiology ; 28) N2 - "To assess the habitability of the icy environments in the solar system, for example, on Mars, Europa, and Enceladus, the scientific analysis of material embedded in or underneath their ice layers is very important. We consider self-steering robotic ice melting probes to be the best method to cleanly access these environments, that is, in compliance with planetary protection standards. The required technologies are currently developed and tested." Y1 - 2013 SN - 978-94-007-6545-0 (Druckausgabe) SN - 978-94-007-6546-7 (E-Book) SP - 367 EP - 397 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Krämer, Stefan A1 - Daab, Dominique Jonas A1 - Müller, Brigitte A1 - Wagner, Tobias A1 - Baader, Fabian A1 - Hessel, Joana A1 - Gdalewitsch, Georg A1 - Plescher, Engelbert A1 - Dachwald, Bernd A1 - Wahle, Michael A1 - Gierse, Andreas A1 - Vetter, Rudolf A1 - Pfützenreuter, Lysan T1 - Development and flight-testing of a system to isolate vibrations for microgravity experiments on sounding rockets JF - 21st ESA Symposium on Rocket and Balloon Research Y1 - 2013 SP - 1 EP - 8 ER - TY - CHAP A1 - Konstantinidis, K. A1 - Dachwald, Bernd A1 - Ohndorf, A. A1 - Dykta, P. A1 - Voigt, K. A1 - Förstner, R. T1 - Enceladus explorer (ENEX): A lander mission to probe subglacial water pockets on Saturn's moon enceladus for life T2 - 64th International Astronautical Congress 2013 (IAC 2013) : Beijing, China, 23 - 27 September 2013. (Proceedings of the International Astronautical Congress, IAC ; 2) Y1 - 2013 SN - 978-1-62993-909-4 SP - 1340 EP - 1350 PB - Curran CY - Red Hook, NY 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 - Dachwald, Bernd A1 - Feldmann, Marco A1 - Espe, Clemens A1 - Plescher, Engelbert A1 - Konstantinidis, K. A1 - Forstner, R. T1 - Enceladus explorer - A maneuverable subsurface probe for autonomous navigation through deep ice T2 - 63rd International Astronautical Congress 2012, IAC 2012; Naples; Italy; 1 October 2012 through 5 October 2012. (Proceedings of the International Astronautical Congress, IAC ; 3) Y1 - 2012 SN - 978-1-62276-979-7 SP - 1756 EP - 1766 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Borggrafe, Andreas A1 - Ohndorf, Andreas A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang T1 - Analysis of interplanetary solar sail trajectories with attitude dynamics T2 - Dynamics and Control of Space Systems 2012 N2 - We present a new approach to the problem of optimal control of solar sails for low-thrust trajectory optimization. The objective was to find the required control torque magnitudes in order to steer a solar sail in interplanetary space. A new steering strategy, controlling the solar sail with generic torques applied about the spacecraft body axes, is integrated into the existing low-thrust trajectory optimization software InTrance. This software combines artificial neural networks and evolutionary algorithms to find steering strategies close to the global optimum without an initial guess. Furthermore, we implement a three rotational degree-of-freedom rigid-body attitude dynamics model to represent the solar sail in space. Two interplanetary transfers to Mars and Neptune are chosen to represent typical future solar sail mission scenarios. The results found with the new steering strategy are compared to the existing reference trajectories without attitude dynamics. The resulting control torques required to accomplish the missions are investigated, as they pose the primary requirements to a real on-board attitude control system. Y1 - 2012 SN - 978-0-87703-587-9 SP - 1553 EP - 1569 PB - Univelt Inc CY - San Diego ER - TY - JOUR A1 - Loeb, Horst Wolfgang A1 - Schartner, Karl-Heinz A1 - Dachwald, Bernd A1 - Ohndorf, Andreas A1 - Seboldt, Wolfgang T1 - Interstellar heliopause probe JF - Труды МАИ N2 - 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. Y1 - 2012 IS - 60 SP - 2 EP - 2 PB - Moskauer Staatliches Luftfahrtinstitut (МАИ) CY - Moskau ER - TY - JOUR A1 - Scholz, Christina A1 - Romagnoli, Daniele A1 - Dachwald, Bernd A1 - Theil, Stephan T1 - Performance analysis of an attitude control system for solar sails using sliding masses JF - Advances in Space Research Y1 - 2011 SN - 0273-1177 VL - 48 IS - 11 SP - 1822 EP - 1835 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dachwald, Bernd A1 - Wurm, Patrick T1 - Mission analysis and performance comparison for an Advanced Solar Photon Thruster JF - Advances in Space Research Y1 - 2011 SN - 0273-1177 VL - 48 IS - 11 SP - 1858 EP - 1868 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Dachwald, Bernd A1 - Xu, Changsheng A1 - Feldmann, Marco A1 - Plescher, Engelbert T1 - IceMole : Development of a novel subsurface ice probe and testing of the first prototype on the Morteratsch Glacier T2 - EGU General Assembly 2011 Vienna | Austria | 03 – 08 April 2011 N2 - We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named “IceMole”, is currently developed, built, and tested at the FH Aachen University of Applied Sciences’ Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth). Y1 - 2011 ER - TY - CHAP A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz A1 - Dachwald, Bernd A1 - Ohndorf, Andreas A1 - Seboldt, Wolfgang T1 - An Interstellar – Heliopause mission using a combination of solar/radioisotope electric propulsion T2 - Presented at the 32nd International Electric Propulsion Conference N2 - 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. Y1 - 2011 N1 - 32nd International Electric Propulsion Conference, 11-15 September. Wiesbaden, Germany SP - 1 EP - 7 ER - TY - CHAP A1 - Ohndorf, Andreas A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Schartner, Karl-Heinz T1 - Flight times to the heliopause using a combination of solar and radioisotope electric propulsion T2 - 32nd International Electric Propulsion Conference N2 - We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks’ parameter set. Based on a parameter space study, in which the number of thrust units, the unit’s specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere’s “nose". KW - low-thrust trajectory optimization KW - heliosphere KW - ion propulsion Y1 - 2011 N1 - IEPC-2011-051 32nd International Electric Propulsion Conference,September 11–15, 2011 Wiesbaden, Germany SP - 1 EP - 12 ER - TY - JOUR A1 - Scholz, A. A1 - Ley, Wilfried A1 - Dachwald, Bernd A1 - Miau, J. J. A1 - Juang, J. C. T1 - Flight results of the COMPASS-1 picosatellite mission JF - Acta Astronautica. 67 (2010), H. 9-10 Y1 - 2010 SN - 0094-5765 SP - 1289 EP - 1298 ER - TY - JOUR A1 - Maiwald, Volker A1 - Dachwald, Bernd T1 - Mission Design for a Multiple-Rendezvous Mission to Jupiter's Trojans Y1 - 2010 N1 - COSPAR 2010 ; 38th COSPAR Scientific Assembly. Held 18-25 July 2010 in Bremen, Germany [Abstract] SP - 3 ER - TY - JOUR A1 - Leimena, W. A1 - Artmann, Gerhard A1 - Dachwald, Bernd A1 - Temiz Artmann, Aysegül A1 - Gossmann, Matthias A1 - Digel, Ilya T1 - Feasibility of an in-situ microbial decontamination of an ice-melting probe JF - Eurasian Chemico-Technological Journal. 12 (2010), H. 2 Y1 - 2010 SN - 1562-3920 SP - 145 EP - 150 ER - TY - CHAP A1 - Borggräfe, Andreas A1 - Dachwald, Bernd T1 - Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients T2 - 2nd International Symposium on Solar Sailing N2 - Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail’s distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed “low” and “medium” sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model. Y1 - 2010 N1 - 2nd International Symposium on Solar Sailing, ISSS 2010, 2010-07-20 - 2010-07-22. New York City College of Technology of the City University of New York, USA SP - 1 EP - 6 ER - TY - CHAP A1 - Dachwald, Bernd T1 - Solar sail dynamics and control T2 - Encyclopedia of Aerospace Engineering N2 - Solar sails are large and lightweight reflective structures that are propelled by solar radiation pressure. This chapter covers their orbital and attitude dynamics and control. First, the advantages and limitations of solar sails are discussed and their history and development status is outlined. Because the dynamics of solar sails is governed by the (thermo-)optical properties of the sail film, the basic solar radiation pressure force models have to be described and compared before parameters to measure solar sail performance can be defined. The next part covers the orbital dynamics of solar sails for heliocentric motion, planetocentric motion, and motion at Lagrangian equilibrium points. Afterwards, some advanced solar radiation pressure force models are described, which allow to quantify the thrust force on solar sails of arbitrary shape, the effects of temperature, of light incidence angle, of surface roughness, and the effects of optical degradation of the sail film in the space environment. The orbital motion of a solar sail is strongly coupled to its rotational motion, so that the attitude control of these soft and flexible structures is very challenging, especially for planetocentric orbits that require fast attitude maneuvers. Finally, some potential attitude control methods are sketched and selection criteria are given. KW - solar sail KW - sailcraft KW - orbital dynamics KW - orbit control KW - attitude dynamics Y1 - 2010 U6 - http://dx.doi.org/10.1002/9780470686652.eae292 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Dachwald, Bernd A1 - Ohndorf, A. A1 - Gill, E. T1 - Optimization of low-thrust Earth-Moon transfers using evolutionary neurocontrol / Ohndorf, A. ; Dachwald, B. ; Gill, E. JF - IEEE Congress on Evolutionary Computation, 2009. CEC '09. Y1 - 2009 SN - 978-1-4244-2958-5 SP - 358 EP - 364 ER -