Abstract
China’s Mars rover, Zhurong, touched down on Utopia Planitia in the northern lowlands of Mars (109.925° E, 25.066° N) in May 2021, and has been conducting in situ investigations of the landing area in conjunction with the Tianwen-1 orbiter. Here we present surface properties derived from the Zhurong rover’s traverse during the first 60 sols of rover operations. Our analysis of the rover’s position from locomotion data and camera imagery over that time shows that the rover traversed 450.9 m southwards over a flat surface with mild wheel slippage. Soil parameters determined by terramechanics, which observes wheel–terrain interactions, indicate that the topsoil has high bearing strength and cohesion. The soil’s equivalent stiffness is estimated to range from 1,390 to 5,872 kPa per mN, and the internal friction angle ranges from 21° to 34° under a cohesion of 1.5 to 6 kPa. Aeolian bedforms in the area are primarily transverse aeolian ridges, indicating northeastern local wind directions. Surface rocks imaged by the rover cameras show evidence of physical weathering processes, such as wind erosion, and potential chemical weathering processes. Joint investigations utilizing the scientific payloads of the rover and the orbiter can provide insights into local aeolian and aqueous history, and the habitability evolution of the northern lowlands on Mars.
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Data availability
The Tianwen-1 data used in this work are produced by the Beijing Aerospace Control Center (BACC). The data used in this manuscript are available at https://doi.org/10.11922/sciencedb.01425. The MOLA base map with geoid elevations is available at https://astrogeology.usgs.gov/search/map/Mars/GlobalSurveyor/MOLA/Mars_MGS_MOLA_DEM_mosaic_global_463m. Source data are provided with this paper.
References
Mallapaty, S. China has landed its first rover on Mars—here’s what happens next. Nature 593, 323–324 (2021).
Li, C. et al. Scientific objectives and payload configuration of China’s first Mars exploration mission. J. Deep Space Explor. 5, 406–413 (2018).
Liang, X. et al. The navigation and terrain cameras on the Tianwen-1 Mars rover. Space Sci. Rev. 217, 37 (2021).
Zhou, B. et al. The Mars rover subsurface penetrating radar onboard China’s Mars 2020 mission. Earth Planet. Phys. 4, 345–354 (2020).
Peng, Y. et al. Overview of the Mars climate station for Tianwen-1 mission. Earth Planet. Phys. 4, 371–383 (2020).
Du, A. et al. The Chinese Mars rover fluxgate magnetometers. Space Sci. Rev. 216, 135 (2020).
Li, C. et al. Design and realization of Chinese Tianwen-1 energetic particle analyzer. Space Sci. Rev. 217, 26 (2020).
Wan, W. et al. Visual localization of the Tianwen-1 lander using orbital, descent and rover Images. Remote Sens. 13, 3439 (2021).
Wu, B. et al. Characterization of the candidate landing region for Tianwen-1—China’s first mission to Mars. Earth Space Sci. 8, e2021EA001670 (2021).
Tanaka, K. L. et al. Geologic Map of Mars: U.S. Geological Survey Scientific Investigations Map 3292 (US Geological Survey, 2014).
Smith, D. E. et al. Mars orbiter laser altimeter—experiment summary after the first year of global mapping of Mars. J. Geophys. Res. 106, 23689–23722 (2001).
Liu, J. et al. Geomorphic contexts and science focus of the Zhurong landing site on Mars. Nat. Astron. https://doi.org/10.1038/s41550-021-01519-5 (2021).
Liu, Z. et al. High precision landing site mapping and rover localization for Chang’e-3 mission. Sci. China Phys. Mech. Astron. 58, 1–11 (2015).
Yang, H. et al. Dynamic simulation of planetary rovers with terrain property mapping. In 2018 IEEE International Conference on Robotics and Automation 738–743 (IEEE Press, 2018).
Li, W., Ding, L., Gao, H., Deng, Z. & Li, N. ROSTDyn: rover simulation based on terramechanics and dynamics. J. Terramech. 50, 199–210 (2013).
Ding, L. et al. A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover. Sci. Robot. 7, abj6660 (2022).
Gao, Y., Spiteri, C., Li, C. & Zheng, Y. Lunar soil strength estimation based on Chang’E-3 images. Adv. Space Res. 58, 1893–1899 (2016).
Wang, Z. et al. Wheels’ performance of Mars exploration rovers: experimental study from the perspective of terramechanics and structural mechanics. J. Terramech. 92, 23–42 (2020).
Ding, L. et al. Interaction mechanics model for rigid driving wheels of planetary rovers moving on sandy terrain with consideration of multiple physical effects. J. Field Robot. 32, 827–859 (2015).
French, B. M., Heiken, G. & Vaniman, D. Lunar Sourcebook: A User’s Guide to the Moon (Cambridge Univ. Press, 1991).
Wong, J. Y. Theory of Ground Vehicles (John Wiley & Sons, 2008).
Henry, J. & Bruce, M. Viking landing sites, remote-sensing observations, and physical properties of Martian surface materials. Icarus 81, 164–184 (1989).
Rover Team Characterization of the Martian surface deposits by the Mars Pathfinder rover, Sojourner. Science 278, 1765–1768 (1997).
Arvidson, R. E. et al. Localization and physical properties experiments conducted by Spirit at Gusev Crater. Science 305, 821–824 (2004).
Arvidson, R. E. et al. Localization and physical property experiments conducted by Opportunity at Meridiani Planum. Science 306, 1730–1733 (2004).
Arvidson, R. E. et al. Terrain physical properties derived from orbital data and the first 360 sols of Mars Science Laboratory Curiosity rover observations in Gale Crater. J. Geophys. Res. 119, 1322–1344 (2013).
Any, S. et al. Phoenix soil physical properties investigation. J. Geophys. Res. 114, E00E0 (2009).
Golombek, M. et al. Geology of the InSight landing site on Mars. Nat. Commun. 11, 1014 (2020).
Zimbelman, J. R. & Foroutan, M. Dingo gap: curiosity went up a small transverse aeolian ridge and came down a megaripple. J. Geophys. Res. 125, e2020JE006489 (2020).
McEwen, A. S. et al. The rayed crater Zunil and interpretation of small impact craters on Mars. Icarus 176, 351–381 (2005).
Mutch, T. A. et al. The surface of Mars: the view from the Viking 1 lander. Science 193, 791–801 (1976).
Head, J. M., Kreslavsky, A. & Marchant, D. R. Pitted rock surfaces on Mars: a mechanism of formation by transient melting of snow and ice. J. Geophys. Res. 116, E09007 (2011).
Cabrol, N. A. et al. Aqueous processes at Gusev crater inferred from physical properties of rocks and soils along the Spirit traverse. J. Geophys. Res. 111, E02S20 (2006).
Arvidson, R. E. et al. Overview of the Spirit Mars Exploration Rover mission to Gusev Crater: landing site to Backstay Rock in the Columbia Hills. J. Geophys. Res. 111, E02S01 (2006).
Thomas, M., Clarke, J. & Pain, C. Weathering, erosion and landscape processes on Mars identified from recent rover imagery, and possible Earth analogues. Aust. J. Earth Sci. 52, 365–378 (2005).
Greeley, R. et al. Gusev crater: wind-related features and processes observed by the Mars Exploration Rover Spirit. J. Geophys. Res. 111, E02S09 (2006).
Thomson, B. J., Bridges, N. T. & Greeley, R. Rock abrasion features in the Columbia Hills, Mars. J. Geophys. Res. 113, E08010 (2008).
Bridges, N. T. et al. Ventifacts at the Pathfinder landing site. J. Geophys. Res. 104, 8595–8615 (1999).
Golombek, M. et al. Selection of the Mars Science Laboratory landing site. Space Sci. Rev. 170, 641–737 (2012).
Zheng, J. et al. Design and terramechanics analysis of a Mars rover utilizing active suspension. Mech. Mach. Theory 128, 125–149 (2018).
Yuan, B. et al. Experimental study on the durability of China’s Mars rover’s mobility system. J. Aerosp. Eng. 34, 04021047 (2021).
Gao, H. et al. Performance analysis on wheels lifting-off-ground for Mars rover with active suspension. Jiqiren 39, 139–150 (2017).
Ding, L., Gao, H., Deng, Z., Yoshida, K. & Nagatani, K. Parameter identification for planetary soil based on a decoupled analytical wheel-soil interaction terramechanics model. In 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems 4122–4127 (IEEE Press, 2009).
Ding, L. Wheel–Soil Interaction Terramechanics for Lunar/Planetary Exploration Rovers: Modeling and Application. PhD thesis, Harbin Institute of Technology (2009).
Shibly, H., Iagnemma, K. & Dubowsky, S. An equivalent soil mechanics formulation for rigid wheels in deformable terrain, with application to planetary exploration rovers. J. Terramech. 42, 1–13 (2005).
Zhao, H. Shock! High-resolution animations reveal how Zhurong rover works on Mars. CCTV https://m.news.cctv.com/2021/06/11/ARTIDKjIkU00BXYFYV0dIpjG210611.shtml (2021).
Acknowledgements
We thank all the scientists and engineers who contributed to the Tianwen-1 mission, in particular those from the China Academy of Space Technology (CAST), Shanghai Academy of Spaceflight Technology (SAST), Harbin Institute of Technology (HIT), Beijing Aerospace Control Center (BACC) and Chinese Academy of Sciences (CAS) for their dedicated work on the Zhurong Mars rover and Tianwen-1 mission. This work was supported in part by: the National Natural Science Foundation of China under Grant 51822502 (L.D.), Grant 91948202 (H.G.), Grant 61972020 (C.L.) and Grant 62003025 (Xiaoxue Wang); the Development Program of China under Grant 2019YFB1309500 (H.G.); the Fundamental Research Funds for the Central Universities under Grant FRFCU9803500621 (L.D.); the ‘111 Project’ under Grant BP0719002 (Z.D.); the Heilongjiang Postdoctoral Fund under Grant LBH-Z20136 (H.Y.); the Self-Planned Task of State Key Laboratory of Robotics and System (HIT) under Grant SKLRS202101A03 (H.Y.); and the Pre-research project on Civil Aerospace Technologies by CNSA under Grant D020102 (Y.Z.).
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L.D. coordinated and wrote the manuscript with R. Zhou. T.Y. led the Zhurong rover operation and data acquisition. H.G and H.Y coordinated co-author contributions. L.D., R. Zhou, H.G., H.Y., Y.Y., Z.W., Z.D., L.H., N.L., Z.L., F.N., H.Q., S.L., W.F., C.Y., H.X., G.W., L.N. and P.X. conducted data and image analysis. T.Y., J.L., C.L., J.W., X.C., X.H., H.Z., R. Zhao, Z.Z., Z.C., F.W., Q.X., H.L., L.L., Xiaoxue Wang, Z.H. and J.Z. performed rover operations, data acquisitions and analyses. Y.J., B.Y., B.C. and Z.D. provided and analysed rover parameters. Y.Z., Xiyu Wang, G.B., W.W., M.Z. and K.D. performed geological analysis and interpretation. G.L. and L.R. refined the results and the writing. All authors reviewed and revised the manuscript.
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Nature Geoscience thanks Fred Calef, Matthew Golombek and Chris Okubo for their contribution to the peer review of this work. Primary Handling Editor: Tamara Goldin, in collaboration with the Nature Geoscience team.
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Extended data
Extended Data Fig. 1 Zhurong rover on Tianwen-1 mission.
a, The group photo of Zhurong rover and Tianwen-1 lander on the Martian surface. The rover dimensions are 2.6 × 3.0 × 1.85 m when fully unfolded, and its mass is 240 kg. The image was taken by a Wi-Fi camera deployed by Zhurong on sol 18 (1 June 2021). Image credit: CNSA/BACC. b, Six scientific payloads, hazard avoidance cameras and the grouser wheel on the Zhurong rover. The six scientific payloads2 include NaTeCam3, Multispectral Camera (MSCam), Mars Rover Penetrating Radar (RoPeR)4, Mars surface Composition Detector (MarSCoDe)7, Mars Rover Magnetometer (RoMAG)6, and Mars Climate Station (MCS)5. Two pairs of hazard avoidance cameras (HazCam), of engineering payloads, are configured forward and backward for stereo observation. The grouser wheel is evenly arranged with 20 grousers on its outer surface and spokes inside. c, Creeping and crabbing modes of the Zhurong rover implemented by taking advantage of the rocker-bogie suspension with active joints46. The creeping mode of Zhurong to get out of sunk and climb steep slopes is realized by decreasing or increasing the angle of the main rocker arm, coordinated with the movement of other wheels. The crabbing mode of Zhurong for lateral movement is achieved by turning the steering wheels at 90° and driving laterally.
Extended Data Fig. 2 Regional topography of the Tianwen-1 landing site.
a, MOLA-derived elevation map of the Tianwen-1 surrounding region in a circular shape. The 20 km diameter circular map is centered at 109.925° E, 24.980° N, about 10 km south of the Tianwen-1 landing site. b, The slope map of the Tianwen-1 surrounding region is based on the MOLA data (baseline 926 m). (The upper layer is a portion of the MOLA shaded-relief topographic map of Mars, which is available at https://astrogeology.usgs.gov/search/map/Mars/GlobalSurveyor/MOLA/Mars_MGS_MOLA_DEM_mosaic_global_463m ; the base map is a 5 m pixel–1 global mosaic of Mars using imagery acquired by the Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO), which is available at http://murray-lab.caltech.edu/.).
Extended Data Fig. 3 Rover locomotion simulation.
The simulation of four traverses after the rover driving off the ramp is visualized. The yellow line represents the planned path, and the blue line represents the path obtained in the simulation. The movement sequence of the rover is carried out in the order of the number marked. The terrain map (DEM covered with orthophoto) is built from NaTeCam images.
Extended Data Fig. 4 Wheel track analysis.
a, Stagged pattern of the wheel track left by a wheel moving with longitudinal slip. b, Wheel track extraction and wheel slip ratio analysis over a traverse to waypoint A. Eight continuous track units are extracted on the orthograph for local wheel slip ratio calculation. The image was taken by the NaTeCam on sol 11. c, d, f, show wheel tracks and the associated wheel sinkage. Images were taken by the rear HazCam. c, A part of the discernable wheel track with well-trimmed edges. The wheel sinkage is estimated to be about 10 mm. d, Most typical form of wheel tracks without well-trimmed edges. Its wheel sinkage is estimated to be ~5 mm. e, Near-Side view of the wheel-terrain interaction. Only wheel grousers are submerged into the soil and the wheel rims of these three right wheels are millimetres above the surface. Some soil adhered to the wheel surface or on the groove bordering the grousers. This image was taken by the Wi-Fi camera on sol 12 when the rover was retreating. f, shows both wheel tracks interrupted by gravels and wheel tracks with rim sinking below the surface. The wheel sinkage of the wheel tracks interrupted by gravels is estimated to be ~2 mm. The wheel sinkage of wheel tracks formed by the wheel rim sinking below the surface is estimated to be ~15 mm. Image credit: CNSA/BACC.
Extended Data Fig. 5 Craters around the Tianwen-1 landing site.
a, The distribution of the mapped craters (diameters > 1 m) in the circular region surrounding the Tianwen-1 landing site, overlaid on the HiRISE image (ESP_069665_2055). C1, C2, C3 are three large craters (diameter > 200 m) in this area. The circular region is centred on 109.925° E, 25.048° N with a diameter of 4 km, and its centre is 1 km south of the Tianwen1 landing site. b, A log-log plot of the incremental sizefrequency distribution of craters. The diameter interval is √2D m and the crater diameter refers to the middle value of each bin. c, A degraded crater with smooth rims imaged by NaTeCam on sol 60 (13 July 2021). d, A crater almost fully filled with sand imaged by NaTeCam on sol 23 (6 June 2021). Image credit: CNSA/BACC.
Extended Data Fig. 6 Rocks around the Tianwen-1 landing site.
a, b, c, are diverse rocks observed by Zhurong rover on the surface. These rocks appear irregular in shapes and have darktoned interiors covered with light-toned soil or dust on the surface. Image credit: CNSA/BACC.
Extended Data Fig. 7 Wheel-soil interaction model and the driving motor characteristics curve.
a, Force diagram for the wheel-soil interaction of a grouser, rigid wheel. b, Characteristics curve of the driving torque and the motor current for the driving motor on the Zhurong rover.
Supplementary information
Supplementary Information
Supplementary Text and Tables 1–4.
Source data
Source Data Fig. 2
Rover positions of each sol derived from visual localization, wheel slip ratio and rover elevations of each sol derived from GNC.
Source Data Fig. 3
Parameters of soils on the Earth and on other landing sites.
Source Data Extended Data Fig. 5
Crater size statistics.
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Ding, L., Zhou, R., Yu, T. et al. Surface characteristics of the Zhurong Mars rover traverse at Utopia Planitia. Nat. Geosci. 15, 171–176 (2022). https://doi.org/10.1038/s41561-022-00905-6
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DOI: https://doi.org/10.1038/s41561-022-00905-6
