TY  - CHAP
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Loeb, Horst W.
A1  - Schartner, Karl-Heinz
T1  - A comparison of SEP and NEP for a main belt asteroid sample return mission
T2  - 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007
N2  - Innovative interplanetary deep space missions, like a main belt asteroid sample
return mission, require ever larger velocity increments (∆V s) and thus ever
more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion
systems can significantly enhance or even enable such high-energy missions. In
1995, a European-Russian Joint Study Group (JSG) presented a study report
on “Advanced Interplanetary Missions Using Nuclear-Electric Propulsion”
(NEP). One of the investigated reference missions was a sample return (SR)
from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant,
Topaz-25, however, could not be realized and also the worldwide developments
in space reactor hardware stalled. In this paper, we investigate, whether such
a mission is also feasible using a solar electric propulsion (SEP) system and
compare our SEP results to corresponding NEP results.
Y1  - 2007
SP  - 1
EP  - 10
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  - 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  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Biele, Jens
A1  - Boden, Ralf
A1  - Ceriotti, Matteo
A1  - Cordero, Federico
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian
A1  - Herčík, David
A1  - Herique, Alain
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Koch, Aaron
A1  - Kofman, Wlodek
A1  - Koncz, Alexander
A1  - Krause, Christian
A1  - Lange, Caroline
A1  - Lichtenheldt, Roy
A1  - Maiwald, Volker
A1  - Mikschl, Tobias
A1  - Mikulz, Eugen
A1  - Montenegro, Sergio
A1  - Pelivan, Ivanka
A1  - Peloni, Alessandro
A1  - Plettemeier, Dirk
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Ruffer, Michael
A1  - Sasaki, Kaname
A1  - Schmitz, Nicole
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Sznajder, Maciej
A1  - Tardivel, Simon
A1  - Toth, Norbert
A1  - Wejmo, Elisabet
A1  - Wolff, Friederike
A1  - Ziach, Christian
T1  - Efficient massively parallel prospection for ISRU by multiple near-earth asteroid rendezvous using near-term solar sails and'now-term'small spacecraft solutions
T2  - 2nd Asteroid Science Intersections with In-Space Mine Engineering – ASIME 2018
N2  - Physical interaction with small solar system bodies (SSSB) is key for in-situ resource utilization (ISRU). The design of mining missions requires good understanding of SSSB properties, including composition, surface and interior structure, and thermal environment. But as the saying goes "If you've seen one asteroid, you've seen one Asteroid": Although some patterns may begin to appear, a stable and reliable scheme of SSSB classification still has to be evolved. Identified commonalities would enable generic ISRU technology and spacecraft design approaches with a high degree of re-use. Strategic approaches require much broader in-depth characterization of the SSSB populations of interest to the ISRU community. The DLR-ESTEC GOSSAMER Roadmap Science Working Groups identified target-flexible Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the missions only feasible with solar sail propulsion, showed the ability to access any inclination and a wide range of heliocentric distances as well as continuous operation close to Earth's orbit where low delta-v objects reside.
Y1  - 2018
N1  - 2nd Asteroid Science Intersections with In-Space Mine Engineering – ASIME 2018
16-17 April 2018, Belval, Luxembourg
SP  - 1
EP  - 33
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Schmidt, Tanja D.
A1  - Seboldt, Wolfgang
A1  - Auweter-Kurtz, 
T1  - Flight Opportunities from Mars to Earth for Piloted Missions Using Continuous Thrust Propulsion / Schmidt, Tanja D. ; Dachwald, Bernd ; Seboldt, Wolfgang ; Auweter-Kurtz, Monika
Y1  - 2003
N1  - 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
20-23 July 2003, Huntsville, Alabama ; AIAA 2003-4573
SP  - 1
EP  - 9
PB  - -
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  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Boden, Ralf
A1  - Ceriotti, Matteo
A1  - Chand, Suditi
A1  - Cordero, Federico
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Heiligers, Jeannette
A1  - Herčík, David
A1  - Hérique, Alain
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Kofman, Wlodek
A1  - Lange, Caroline
A1  - Lichtenheldt, Roy
A1  - McInnes, Colin
A1  - Meß, Jan-Gerd
A1  - Mikschl, Tobias
A1  - Mikulz, Eugen
A1  - Montenegro, Sergio
A1  - Moore, Iain
A1  - Pelivan, Ivanka
A1  - Peloni, Alessandro
A1  - Plettemeier, Dirk
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Rogez, Yves
A1  - Ruffer, Michael
A1  - Sasaki, Kaname
A1  - Schmitz, Nicole
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Sznajder, Maciej
A1  - Tóth, Norbert
A1  - Vergaaij, Merel
A1  - Viavattene, Giulia
A1  - Wejmo, Elisabet
A1  - Wiedemann, Carsten
A1  - Wolff, Friederike
A1  - Ziach, Christian
T1  - Flights are ten a sail – Re-use and commonality in the design and system engineering of small spacecraft solar sail missions with modular hardware for responsive and adaptive exploration
T2  - 70th International Astronautical Congress (IAC)
KW  - system engineering
KW  - small solar system body characterisation
KW  - small spacecraft solar sail
KW  - small spacecraft asteroid lander
KW  - responsive space
Y1  - 2019
SN  - 9781713814856
N1  - 70th International Astronautical Congress (IAC), Washington D.C., United States, 21-25 October 2019
SP  - 1
EP  - 7
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Boehnhardt, Herrmann
A1  - Broj, Ulrich
A1  - Geppert, Ulrich R. M. E.
A1  - Grundmann, Jan-Thimo
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Johnson, Les
A1  - Kührt, Ekkehard
A1  - Mottola, Stefano
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R.
A1  - Vasile, Massimiliano
A1  - Reinhard, Ruedeger
T1  - Gossamer roadmap technology reference study for a multiple NEO Rendezvous Mission
T2  - Advances in solar sailing
N2  - A technology reference study for a multiple near-Earth object (NEO) rendezvous mission with solar sailcraft is currently carried out by the authors of this paper. The investigated mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy based on the DLR/ESA Gossamer technology. The main scientific objective of the mission is to explore the diversity of NEOs. After direct interplanetary insertion, the solar sailcraft should—within less than 10 years—rendezvous three NEOs that are not only scientifically interesting, but also from the point of human spaceight and planetary defense. In this paper, the objectives of the study are outlined and a preliminary potential mission profile is presented.
Y1  - 2014
SN  - 978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)
SP  - 211
EP  - 226
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - McInnes, Colin R.
A1  - Bothmer, Volker
A1  - Dachwald, Bernd
A1  - Geppert, Ulrich R. M. E.
A1  - Heiligers, Jeannette
A1  - Hilgers, Alan
A1  - Johnson, Les
A1  - Macdonald, Malcolm
A1  - Reinhard, Ruedeger
A1  - Seboldt, Wolfgang
A1  - Spietz, Peter
T1  - Gossamer roadmap technology reference study for a Sub-L1 Space Weather Mission
T2  - Advances in solar sailing
N2  - A technology reference study for a displaced Lagrange point space weather mission is presented. The mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy to deliver a low mass platform and payload which can be accommodated on the DLR/ESA Gossamer-3 technology demonstration mission. A direct escape from Geostationary Transfer Orbit is assumed with the sail deployed after the escape burn. The use of a miniaturized, low mass platform and payload then allows the Gossamer-3 solar sail to potentially double the warning time of space weather events. The mission profile and mass budgets will be presented to achieve these ambitious goals.
Y1  - 2014
SN  - 978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)
SP  - 227
EP  - 242
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Spurmann, Jörn
A1  - Ohndorf, Andreas
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Löb, Horst
A1  - Schartner, Karl-Heinz
T1  - Interplanetary trajectory optimization for a sep mission to Saturn
T2  - 60th International Astronautical Congress 2009
N2  - The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.
KW  - Spacecraft
KW  - Reusable Rocket Engines
KW  - Hybrid Propellants
Y1  - 2009
SN  - 9781615679089
N1  - 60th International Astronautical Congress 2009 (IAC 2009)
Held 12-16 October 2009, Daejeon, Republic of Korea.
SP  - 5234
EP  - 5248
ER  -