R. J. Sullivan's research while affiliated with Cornell University and other places

Publications (57)

Article
Three-dimensional discrete element method (DEM) simulations were developed for the Mars Exploration Rover (MER) mission to investigate: (1) rover wheel interactions with martian regolith; and (2) regolith deformation in a geotechnical triaxial strength cell (GTSC). These DEM models were developed to improve interpretations of laboratory and in situ...
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Combined observations from the MER rovers on the surface and the MRO HiRISE camera in orbit show that Martian winds actively alter the planet's surface on seasonal and geological time scales.
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Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of the atmosphere, soils, and rocks. This paper provides an overview of key discoveries between sols 511 and 2300, complementing earlier papers covering results from the initial phases of the mission. Key new results include (1) atmos...
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1] This paper summarizes Spirit Rover operations in the Columbia Hills, Gusev crater, from sol 1410 (start of the third winter campaign) to sol 2169 (when extrication attempts from Troy stopped to winterize the vehicle) and provides an overview of key scientific results. The third winter campaign took advantage of parking on the northern slope of H...
Conference Paper
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The Mars Science Laboratory has two color science mast cameras with 15° and 5° fields of view (FOV). They take 1200 × 1600 RGB and science filter images, with JPEG and lossless compression, into 8-Gigabyte buffers.
Conference Paper
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The Mars Science Laboratory (MSL) rover, Curiosity, is expected to land on Mars in 2012. The Mars Hand Lens Imager (MAHLI) will be used to document martian rocks and regolith with a 2-megapixel RGB color CCD camera with a focusable macro lens mounted on an instrument-bearing turret on the end of Curiosity's robotic arm. The flight MAHLI can focus...
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The Mars rover Opportunity has explored Victoria crater, an approximately 750-meter eroded impact crater formed in sulfate-rich sedimentary rocks. Impact-related stratigraphy is preserved in the crater walls, and meteoritic debris is present near the crater rim. The size of hematite-rich concretions decreases up-section, documenting variation in th...
Conference Paper
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The MSL Mars Hand Lens Imager (MAHLI) flight instrument has been completed and delivered to JPL for installation on the rover. MAHLI is a focusable color camera that can image geologic materials at resolutions as high as 14 microns per pixel.
Article
This paper summarizes the Spirit rover operations in the Columbia Hills of Gusev Crater from sols 513 to 1476 and provides an overview of selected findings that focus on synergistic use of the Athena Payload and comparisons to orbital data. Results include discovery of outcrops (Voltaire) on Husband Hill that are interpreted to be altered impact me...
Article
Victoria crater (2.05N, 354.51E) is ~750 m in diameter and the largest crater on Mars observed in situ. The Mars Exploration Rover Opportunity traversed NW to SE across a broad annulus dominated by dark sand that at least partially surrounds the crater before navigating the northern crater rim. Rover observations of the crater and ejecta deposits a...
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A combination of terrestrial laboratory tests of MER wheel interaction with Mars regolith simulant combined with DEM simulations are being developed. A preliminary DEM simulation of the MER wheel/soil system is being used to conduct a first order examinat
Article
Grain-size analyses of the soils at Meridiani Planum have been used to identify rock sources for the grains and provide information about depositional processes under past and current conditions. Basaltic sand, dust, millimeter-size hematite-rich spherules interpreted as concretions, spherule fragments, coated partially buried spherules, basalt fra...
Article
The Mars Exploration Rover Opportunity touched down at Meridiani Planum in January 2004 and since then has been conducting observations with the Athena science payload. The rover has traversed more than 5 km, carrying out the first outcrop-scale investigation of sedimentary rocks on Mars. The rocks of Meridiani Planum are sandstones formed by eolia...
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Erosion rates derived from the Gusev cratered plains and the erosion of weak sulfates by saltating sand at Meridiani Planum are so slow that they argue that the present dry and desiccating environment has persisted since the Early Hesperian. In contrast, sedimentary rocks at Meridiani formed in the presence of groundwater and occasional surface wat...
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1] The $5 km of traverses and observations completed by the Opportunity rover from Endurance crater to the Fruitbasket outcrop show that the Meridiani plains consist of sulfate-rich sedimentary rocks that are largely covered by poorly-sorted basaltic aeolian sands and a lag of granule-sized hematitic concretions. Orbital reflectance spectra obtaine...
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Wind-related features observed by the rover Spirit in Gusev crater, Mars, include patches of soil on the surface, some of which are organized into bed forms. Windblown grains include dust (inferred to be 2 mm in diameter). Microscopic Imager data show the sands and granules to be rounded and relatively spherical, typical of grains transported long...
Conference Paper
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Based on operational experience gained during the Mars Exploration Rover (MER) mission, we proposed and were selected to conduct two related imaging experiments: (1) an investigation of the geology and short-term atmospheric vertical wind profile local to the Mars Science Laboratory (MSL) landing site using descent imaging, and (2) a broadly-based...
Conference Paper
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The MArs Hand Lens Imager (MAHLI) is a small, RGB-color camera designed to examine geologic material at 12.5-75 microns/pixel resolution at the Mars Science Laboratory (MSL) landing site. MAHLI is a PI-led investigation competitively selected by NASA in December 2004 as part of the science payload for the MSL rover launching in 2009. The instrument...
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Introduction. The panoramic camera (Pancam) multispectral, stereoscopic imaging systems on the Mars Exploration Rovers Spirit and Opportunity [1] have acquired and downlinked more than 45,000 images (~35 Gbits of data) over more than 700 combined sols of operation on Mars as of early January 2005. A large subset of these images were acquired as par...
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The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within smal...
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Panoramic Camera (Pancam) images from Meridiani Planum reveal a low-albedo, generally flat, and relatively rock-free surface. Within and around impact craters and fractures, laminated outcrop rocks with higher albedo are observed. Fine-grained materials include dark sand, bright ferric iron-rich dust, angular rock clasts, and millimeter-size sphero...
Article
The location of the Opportunity landing site was determined to better than 10-m absolute accuracy from analyses of radio tracking data. We determined Rover locations during traverses with an error as small as several centimeters using engineering telemetry and overlapping images. Topographic profiles generated from rover data show that the plains a...
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Panoramic Camera images at Gusev crater reveal a rock-strewn surface interspersed with high- to moderate-albedo fine-grained deposits occurring in part as drifts or in small circular swales or hollows. Optically thick coatings of fine-grained ferric iron-rich dust dominate most bright soil and rock surfaces. Spectra of some darker rock surfaces and...
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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...
Article
Wind-abraded rocks, ripples, drifts, and other deposits of windblown sediments are seen at the Columbia Memorial Station where the Spirit rover landed. Orientations of these features suggest formative winds from the north-northwest, consistent with predictions from atmospheric models of afternoon winds in Gusev Crater. Cuttings from the rover Rock...
Article
This abstract describes the initial results from the high resolution multispectral imaging cameras on the Mars Exploration Rovers.
Conference Paper
This abstract describes the initial results from the high resolution multispectral imaging cameras on the Mars Exploration Rovers.
Article
A number of physical properties experiments will be conducted during the NASA 2003 Mars Exploration Rover Mission as the two vehicles explore Meridiani Planum and the floor of Gusev Crater. The investigations will include quantifying dust accumulation and dispersal dynamics by periodically monitoring the rover decks with the Athena Pancam and Mini-...
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1] The Panoramic Camera (Pancam) investigation is part of the Athena science payload launched to Mars in 2003 on NASA's twin Mars Exploration Rover (MER) missions. The scientific goals of the Pancam investigation are to assess the high-resolution morphology, topography, and geologic context of each MER landing site, to obtain color images to constr...
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We utilize imaging data from the Galileo spacecraft to investigate band formation on one of Jupiter's moons, Europa. Bands are polygonal features first observed in Voyager data close to Europa's anti-Jovian point and represent areas where preexisting terrain has been pulled apart, allowing new material to move up into the gap. We examine the detail...
Conference Paper
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GEM-era investigations of impact features on Europa have focused on: (1) the deposits of Mannann'an; (2) Tegid; (3) the topography of craters; (4) Pwyll secondaries; and (5) a survey and ordering of all primary impact features.
Article
Initial analysis of degradational processes on scarps and slopes on Io using just-acquired images by the Galileo SSI team. Among other results, is evidence for sublimation, sapping, and perhaps "glacial" flow of interstitial volatiles in relief-forming materials.
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It has been proposed that Jupiter's satellite Europa currently posesses a global subsurface ocean of liquid water. Galileo gravity data verify that the satellite is differentiated into an outer H2O layer about 100 km thick but cannot determine the current physical state of this layer (liquid or solid). Here we summarize the geological evidence rega...
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Theoretical modeling suggests that certain low-albedo features on Europa might represent lag deposits of dark non-ice material resulting from enhanced ice sublimation in response to conductive heating by subsurface cryomagmatic intrusions or diapirs.
Conference Paper
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Images at scales of 2-15 m/pixel from the Mars Orbiter Camera on the Mars Global Surveyor provide a view of Mars surface eolian processes and materials at a scale intermediate between lander images and Viking Orbiter data. These images reveal a variety of dune materials, superposition of dune types, geographically specific erosional styles, widespr...
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Galileo's Solid State Imaging camera recorded six images at wavelengths from 0.41 to 0.99 μm of Europa's trailing hemisphere (∼1.6 km/pixel resolution) during the G1 orbit (1st orbit—target Ganymede) of the nominal mission. We have photometrically corrected these data and extracted spectra representing Europa's diverse geologic terrains. The goals...
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The ice-rich surface of the jovian satellite Europa is sparsely cratered, suggesting that this moon might be geologically active today. Moreover, models of the satellite's interior indicate that tidal interactions with Jupiter might produce enough heat to maintain a subsurface liquid water layer. But the mechanisms of interior heat loss and resurfa...
Article
The solid-state imaging subsystem (SSI) on NASA's Galileo Jupiter orbiter spacecraft has already demonstrated its superior performance as a scientific imager by returning stunning pictures of several planetary bodies as well as detailed inflight calibration data during its cruise to Jupiter. The SSI inflight performance remains excellent; the instr...
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Voyager images of the surface of Europa revealed several circular features identified to various degrees of certainty as impact features. The arrival of the Galileo Orbiter in the Jupiter system has offered an opportunity to examine several impact features on Europa at considerably better resolution and greater spectral coverage than was possible b...
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At high resolution Galileo imaging of a portion of Jupiter's satellite Europa reveals that its late-stage geology is dominated by circular to elliptical pits, domes, and dark spots about 7-15 km across, spaced from 5 to 20 km apart, as well as a larger region of chaotic terrain. A sequence of increasing surface disruption appears to be represented...
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New images of Callisto's surface, at high resolution, by the Galileo SSI instrument, have revealed a startling lack of craters at small and intermediate sizes (less than 10 km). Based on the cratering record observed at larger sizes by Voyager (Woronow, Strom, and Gurnis 1982, ``Interpreting the Cratering Record: Mercury to Ganymede and Callisto",...
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Galileo imaging of Europa reveals a sparsely cratered surface and a complex array of dark and bright bands, ridges, and troughs. "Pull-apart" features are bands that indicate separation and spreading of the satellite's lithosphere, as they can be reconstructed through translation and rotation of lithospheric blocks. Reconstruction of a 5 km wide ri...
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Voyager images of the surface of Europa revealed many diverse features, including bright and dark linea, triple bands, gray bands, ridges, pits, and dark spots termed maculae. Seen at Voyager resolution, maculae are circular to irregularly shaped, low albedo patches with little additional morphologic character. Maculae occur in both bright and mott...
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The objectives of this study are determine the extent and morphologic expression of landforms and surface textures that are indicative of exogenic degradation in the icy Galilean satellites. We develop working hypotheses for the evolution of these landforms and surface materials and model the parameters of various hypotheses which can be tested aga...
Article
Early wind tunnel experiments and the Viking Lander experience led to concepts of grain evolution and regolith development on Mars. Wind tunnel experiments showed that 100-150 mum grains are easiest to entrain on Mars, but at 10 times higher wind speeds than on Earth. Even if trajectory speeds of martian saltating grains achieve smaller fractions o...
Article
Various wind-related features exist at the Spirit (Gusev) and Opportunity (Sinus Meridiani) sites, including those seen from the surface (e.g., ripples, "wind tails" associated with rocks, and ventifacts), and from orbit (e.g., linear low-albedo patterns, some of which change with time). The orientations of these features suggest that formative win...
Article
We report on preliminary comparison of discrete element method (DEM) simulations of laboratory tests of the Mars Exploration Rovers (MER) wheel/soil interaction. These are used to calibrate the DEM to analyze MER data to determine soil properties.
Article
Laboratory tests and discrete element methods (DEM) are being developed to determine soil mechanical properties from Mars Exploration Rover wheel trenching, Mössbauer contact plate indentation, and other soils tests. DEM simulations reduce uncertainties caused by test geometry.
Article
The Mars Exploration Rovers Spirit and Opportunity have enabled more than six and a half years of detailed, in situ field study of two specific landing sites and traverse paths within Gusev crater and Meridiani Planum, respectively. Much of the study has relied on high-resolution, multispectral imaging of fine-grained regolith components--the dust,...

Citations

... Nonetheless, in recent years significant improvements have been made in the range of data that are being returned from Mars for use by geomorphologists. These include satellite data with spatial resolutions of up to 1.5 m/pixel (Malin and Edgett, 2001) and temporal resolution of months to years (Edgett et al., 2000). Laser altimetry has resulted in the production of a global topographic map (Smith et al., 1999), and a stereo camera (i.e., the HRSC on Mars Express) allows for the estimation of topography at a scale that is suited to geomorphic studies of mediumscale landforms (e.g., Jaumann et al., 2005). ...
... It has been proposed therefore to use a complementary instrument based on exciting native autofluorescence from Martian organic compounds, or biomolecules within microorganisms, to rapidly survey potential target regions or triage samples before scrutiny with more discriminatory instruments Storrie-Lombardi et al. 2008Weinstein et al. 2008;Muller et al. 2009;Dartnell et al. 2010Dartnell et al. , 2011Dartnell et al. , 2012. Such an instrument could employ either UV laser diodes for remote detection or UV LEDs with a close-up imager (such as the Mars hand lens imager, MAHLI, aboard Mars Science Laboratory, which has two 365 nm LEDs for UV illumination at night; Edgett et al. 2009). ...
... The Mastcam (Mast Camera) instrument consists of one pair of full-color high-resolution cameras with filter wheels for multispectral imaging. The two cameras have different focal lengths, 34 and 100 mm for Mastcam left (ML) and right (MR), respectively (Bell et al., 2017;Malin et al., 2010Malin et al., , 2017. The MAHLI instrument is a full-color high-resolution micro-imager positioned at the end of the robotic arm of the rover, able to resolve coarse silt grains (12 μm/px) from a distance of ∼2 to ∼4 cm (Edgett et al., 2012). ...
... A well-developed sensing device carried by the rover would greatly facilitate the complex risk-reducing operations. The concept of instrumented wheel deployed in front of the robotic rover to provide representative terrain loading information is very promising, including the Wheeled Bevameter (WB) [12] and the Legged PathBeater (LPB) [13]. The WB is a sensing wheel that originates from the traditional bevameter in terrestrial trafficability test for off-road vehicles and became popular due to the ExoMars project [11]. ...
... Several other groups—in Europe and beyond— contribute substantially to space simulation experiments using soil simulants. Recent Mars missions provided a great wealth of knowledge about different Martian soil types (see Banin, 2005; Bell et al., 2000; Herkenhoff et al., 2004; Johnson et al., 2007; Richter et al., 2006; Soderblom et al., 2004, for example). We will, wherever possible, compare our findings about Martian analogues with in situ measurements. ...
... The melt streaks in Haughton crater provide an intriguing comparison to a suite of slope features locally common on Martian slopes. These include gullies (Christensen, 2003) with attendant flows (Malin et al., 2006), slope streaks (Edgett et al., 2000) and recurring slope lineae or RSL (McEwen et al., 2011), as shown in Fig. 7. The formation of these features is contested. ...
... . Soft particle contact generating overlap tions, like in mining applications (conveyors and mills), excavation processes [9], [10], [11], [12], [13], rock mechanics [22], civil engineering [23] and geomechanics [24]. Wheel-soil interaction studies have been carried out in [18], [19], [20], [17], [21], [15], [16]. The approaches described in [15] and [16] are the only ones that cover three dimensions. ...
... Compared with the surface denudation rate of 100 nm/y reported for the VL2 landing site in northern Utopia Planitia by Arvidson et al. (1979), the value for the Zhurong landing site in southern Utopia Planitia is considerably smaller, and the surface denudation rate at the VL1 landing site in western Chryse Planitia is only 1 nm/y since the late Hesperian. For other landing sites, MPF and Spirit report similar estimations of 0.02 nm/y and 0.03 nm/y since 3.5 Ga and 3.1 Ga, respectively (Golombek & Bridges, 2000;Golombek et al., 2006), but the estimate for the Opportunity landing site is 1-2 orders of magnitude larger, from 1.3 nm/y to 15 nm/y. Haas et al. (2013) reported a considerably high rock breakdown rate of 3.5 m/Ma and surface denudation rate of 0.89 m/Ma on the fan in eastern Promethei Terra, suggestive of an abnormally high erosion rate in the Amazonian period. ...
... It was visited by the MER- B Opportunity Rover, between Sols 952 and 1293 of operation. 100 -150 m of erosional widening [3] has produced outcrops of pre-impact aeolian deposits < 15 m high, which form the upper dry section of a dry-wet-dry depositional sequence known as the Burns Formation [1]. Fully 3D outcrops exposed in the promontories of the crater wall show 3 -7 m thick bedsets of large-scale cross-bedding, which have been interpreted as an ancient aeolian dune system [4]. ...
... 2c) [26,32]. Все такие особенности для своего объяснения требуют наличия под поверхностью источника тепла [20]. Понятно, что большая плотность воды сравнительно со льдом предотвращает всплывание жидкой воды сквозь ледяную кору из чистой воды. ...