The SherpaTT rover is prepared for further autonomous long distance traverses in terrain akin to the Martian environment. However, it features a fueled power generator which cannot be employed in Martian or Lunar missions and limits the system's autonomous mission lifetime to the discharge rate of its two LiPo batteries. As the rover is meant to approach a higher technology readiness level, further development is required on its electrical power subsystem if it is to operate in long term missions. The thesis will explore solar array configurations with respect to constraints imposed by the Martian and Lunar environments so that future versions of the rover may be designed to navigate the surface of these celestial bodies. Mars mission scenarios will be explored in order to propose solar array requirements and impose power consumption constraints based on sol-by-sol analysis of solar insolation as a function of geographic latitude, areocentric longitude, atmospheric opacity, dust deposition, and sun angle of incident on the solar array. In order to establish a baseline power budget analysis for SherpaTT, the thesis looks at a past Mars mission with Opportunity's attempted descent into Victoria crater. Entering the crater through an area called "Duck Bay", the rover was to zigzag back and forth across the crater's steep slope. However, on Sol 1600, one of the wheel motors drew an unexpected high level of current due to a short or an open circuit. No natural obstruction was observed and the cause of the anomaly was never determined. The decision was made to exit the crater out of concern that the rover could not rely on only five wheels to get out. Victoria crater's bay surfaces slope into the crater at an average of 19°. Using SherpaTT Utah field test data for a slope range from 9° to 28°, an initial solar panel and battery sizing as well as a power budget analysis will be presented on what it would take for SherpaTT to completely descend and then exit Victoria crater. This baseline analysis will serve to plan power budgets for other mission scenarios to explore sites of interest on the Martian surface.
Solar Array Integration on SherpaTT Rover Considering Mars and Lunar Deployments
VeranstaltungsortRaum Seminarraum 117, Robert-Hooke-Str. 5 in Bremen
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