Localization and physical properties experiments conducted by Spirit at Gusev Crater.

Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA.
Science (Impact Factor: 31.2). 09/2004; 305(5685):821-4. DOI:10.1126/science.1099922
Source: DLR

ABSTRACT The precise location and relative elevation of Spirit during its traverses from the Columbia Memorial station to Bonneville crater were determined with bundle-adjusted retrievals from rover wheel turns, suspension and tilt angles, and overlapping images. Physical properties experiments show a decrease of 0.2% per Mars solar day in solar cell output resulting from deposition of airborne dust, cohesive soil-like deposits in plains and hollows, bright and dark rock coatings, and relatively weak volcanic rocks of basaltic composition. Volcanic, impact, aeolian, and water-related processes produced the encountered landforms and materials.

0 0
1 Bookmark
  • [show abstract] [hide abstract]
    ABSTRACT: A laser-induced breakdown spectroscopy (LIBS) instrument is traveling to Mars as part of ChemCam on the Mars Science Laboratory rover. Martian rocks have weathered exteriors that obscure their bulk compositions. We examine weathered rocks with LIBS in a martian atmosphere to improve interpretations of ChemCam rock analyses on Mars. Profile data are analyzed using principal component analysis, and coatings and rinds are examined using scanning electron microscopy and electron probe microanalysis. Our results show that LIBS is sensitive to minor compositional changes with depth and correctly identifies rock type even if the series of laser pulses does not penetrate to unweathered material.
    Applied Optics 03/2012; 51(7):B74-82. · 1.69 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe(+3)-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precipitated from fluids that circulated after the Endeavour impact. Compositional data for fractures in the layered rocks suggest formation of Al-rich smectites by aqueous leaching. Evidence is thus preserved for water-rock interactions before and after the impact, with aqueous environments of slightly acidic to circum-neutral pH that would have been more favorable for prebiotic chemistry and microorganisms than those recorded by younger sulfate-rich rocks at Meridiani Planum.
    Science 01/2014; 343(6169):1248097. · 31.20 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: With the increasing challenges facing planetary exploration missions and the resultant increase in the performance requirements for planetary rovers, terramechanics (wheel---soil interaction mechanics) is playing an important role in the development of these rovers. As an extension of the conventional terramechanics theory for terrestrial vehicles, the terramechanics theory for planetary rovers, which is becoming a new research hotspot, is unique and puts forward many new challenging problems. This paper first discusses the significance of the study of wheel---soil interaction mechanics of planetary rovers and summarizes the differences between planetary rovers and terrestrial vehicles and the problems arising thereof. The application of terramechanics to the development of planetary rovers can be divided into two phases (the R&D phase and exploration phase for rovers) corresponding to the high-fidelity and simplified terramechanics models. This paper also describes the current research status by providing an introduction to classical terramechanics and the experimental, theoretical, and numerical researches on terramechanics for planetary rovers. The application status of the terramechanics for planetary rovers is analyzed from the aspects of rover design, performance evaluation, planetary soil parameter identification, dynamics simulation, mobility control, and path planning. Finally, the key issues for future research are discussed. The current planetary rovers are actually advanced wheeled mobile robots (WMRs), developed employing cutting-edge technologies from different fields. The terramechanics for planetary rovers is expected to present new challenges and applications for WMRs, making it possible to develop WMRs using the concepts of mechanics and dynamics.
    Intelligent Service Robotics 01/2011; 4(1):17-38.

Full-text (4 Sources)

Available from
Feb 28, 2013