Browsing by Author "Sommer, Maximilian"

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Open Access
Modelling cometary meteoroid stream traverses of the Martian Moons eXploration (MMX) spacecraft en route to Phobos
(2021) Krüger, Harald; Kobayashi, Masanori; Strub, Peter; Moragas-Klostermeyer, Georg; Sommer, Maximilian; Kimura, Hiroshi; Grün, Eberhard; Srama, Ralf
The Martian Moons Exploration (MMX) spacecraft is a JAXA mission to Mars and its moons Phobos and Deimos. MMX will be equipped with the Circum-Martian Dust Monitor (CMDM) which is a newly developed light-weight (650g) large area (1m2) dust impact detector. Cometary meteoroid streams (also referred to as trails) exist along the orbits of comets, forming fine structures of the interplanetary dust cloud. The streams consist predominantly of the largest cometary particles (with sizes of approximately 100μm to 1 cm) which are ejected at low speeds and remain very close to the comet orbit for several revolutions around the Sun. The Interplanetary Meteoroid Environment for eXploration (IMEX) dust streams in space model is a new and recently published universal model for cometary meteoroid streams in the inner Solar System. We use IMEX to study the detection conditions of cometary dust stream particles with CMDM during the MMX mission in the time period 2024 to 2028. The model predicts traverses of 12 cometary meteoroid streams with fluxes of 100μm and bigger particles of at least 10-3m-2day-1 during a total time period of approximately 90 days. The highest flux of 0.15m-2day-1 is predicted for comet 114P/Wiseman-Skiff in October 2026. With its large detection area and high sensitivity CMDM will be able to detect cometary meteoroid streams en route to Phobos. Our simulation results for the Mars orbital phase of MMX also predict the occurrence of meteor showers in the Martian atmosphere which may be observable from the Martian surface with cameras on board landers or rovers. Finally, the IMEX model can be used to study the impact hazards imposed by meteoroid impacts onto large-area spacecraft structures that will be particularly necessary for crewed deep space missions.
Open Access
Science planning for the DESTINY+ Dust Analyzer : leveraging the potential of a space exploration instrument
(2024) Sommer, Maximilian; Srama, Ralf (Apl. Prof. Dr.-Ing.)
The DESTINY+ Dust Analyzer (DDA) is a highly sophisticated planetary science instrument to provide cutting-edge in-situ characterization of individual cosmic dust grains, with respect to their composition, as well as their physical and dynamical properties. As such, it constitutes a critical component of the upcoming JAXA mission DESTINY+, which is scheduled to launch in 2025. After a three-year cruise phase, the spacecraft will perform a flyby of the target asteroid 3200 Phaethon, with the goal of observing the enigmatic Geminids parent body with two camera instruments, and sampling particles released from its surface with the DDA. Until that flyby, DESTINY+ will execute a highly diverse, ion-engine-driven flight plan that allows DDA to extensively study the dust environments of the Earth, Moon, and interplanetary space - a breadth of science opportunities that is unique to this mission and instrument. This dissertation provides a comprehensive study of the dust types and phenomena possibly encountered by DDA during its journey to Phaethon and applies the principles and methods of science planning to prepare for the operational phase of the mission. The work synthesizes technical considerations and scientific analyses of relevant cosmic dust populations, aiming to optimize DDA’s scientific potential. Detailed examinations of spacecraft and instrument factors, such as the dynamic spacecraft attitude during the near-Earth phase or the instrument’s two-axis pointing mechanism, lay the groundwork for the scientific planning. The thorough analysis of known (and lesser known) dust populations in the inner solar system and of previous relevant measurements by other dust instruments form the core of the study. Finally, the findings are consolidated into a draft science activity plan for the entire mission, as well as exemplary pointing timelines to be executed by the instrument for optimal scientific return. The latter is accomplished with the DOPE tool, which aids in intuitive and efficient planning of DDA observations, having been developed in the scope of this project. The presented work builds the foundation for the scientific operations of DDA, setting it up for a successful and scientifically impactful mission. The findings of this study also provide a valuable perspective for other ventures of in-situ dust astronomy to the inner solar system and contribute to the field of cosmic dust as a whole.
Open Access
Upgrades of a small electrostatic dust accelerator at the University of Stuttgart
(2023) Li, Yanwei; Bauer, Marcel; Kelz, Sebastian; Strack, Heiko; Simolka, Jonas; Mazur, Christian; Sommer, Maximilian; Mocker, Anna; Srama, Ralf
In this paper, we describe the upgrade of a small electrostatic dust accelerator located at the University of Stuttgart. The newly developed dust source, focusing lens, differential detector and linac stage were successfully installed and tested in the beam line. The input voltage range of the dust source was extended from 0-20 kV to 0-30 kV. A newly developed dust detector with two differential charge sensitive amplifiers is employed to monitor particles with speeds from several m/s to several km/s and with surface charges above 0.028 fC. The post-stage linac provides an additional acceleration ability with a total voltage of up to 120 kV. The entire system of this dust accelerator works without protection gas and without a complex high voltage terminal. The volumes to be pumped down are small and can be quickly evacuated. The new system was used to accelerate micron- and submicron-sized metal particles or coated mineral materials. Improvements in the acceleration system allow for a wider variety of dust materials and new applications.