Entwicklung der elektronischen Steuerung für die autonomen Schmelzsonden des akustischen Ortungsnetzwerks im EnEx-RANGE-Projekt

• Main Author: Weinstock, Lars Steffen
• Other Authors: Wiebusch, Christopher, Abel, Dirk
• Format: Doctoral or Postdoctoral Thesis
• Language: German
• Published: 2019
• Subjects: info:eu-repo/classification/ddc/530; Enceladus; Schmelzsonde; akustischer Emitter; elektronische Steuerung; Antarc*; Antarctica
• Online Access: https://publications.rwth-aachen.de/record/773555; https://publications.rwth-aachen.de/search?p=id:%22RWTH-2019-11183%22

Saturn's moon Enceladus is a very interesting candidate for the search for extraterrestrial life: Below the moons thick icy crust lies a global saline ocean, that could support microbiological life. In order to develop technologies for a future space mission to Enceladus the German Aerospace Center started the Enceladus Explorer Initiative. The goal of the mission is to land on the surface of the moon and to deploy a maneuverable melting probe, that penetrates the ice hull. The probe then locates a water-filled crevasse close to the surface, takes a water sample, and analyses it for signs of microbiological life. Such a probe, the IceMole, was developed during the EnEx collaboration und successfully tested in Antarctica. In the follow-on project EnEx-RANGE the acoustic positioning system of the IceMole was improved by replacing the acoustic surface emitters with acoustically instrumented melting probes. These probes, the APUs, are able to descend with the IceMole and form a robust reference system, in which the positions of all APUs and the IceMole can be determined measuring the acoustic signal travel times. Additionally this acoustic positioning network collects information about the ice volume e.g. the position of obstacles and crevasses. In total 13 APUs were developed, built, and successfully tested on alpine glaciers during the EnEx-RANGE project. The electronic control system for the APUs was developed within the scope of this thesis. This control system enables an APU to monitor its internal state (e.g. temperature and pressure), to melt into the ice with a total power of 2.4 kW, and to emit acoustic signals: The maximum range of the acoustic signals at the optimum signal frequency of 10.1 kHz and a signal-to-noise ratio of 10:1 is 38 m. In addition to the development of the electronics of the control system the mechanical construction of the acoustic emitter of the APU was analysed and modifications worked out to further improve the emitters range. To demonstrate the capabilities of the control system a ...