Landing Site Selection and Characterization of Tianwen‐1 (Zhurong Rover) on Mars

Abstract

China's first Mars rover, Zhurong, successfully landed in southern Utopia Planitia on the Martian surface (Figure 1) on 15 May 2021. Zhurong was onboard the Tianwen-1 probe, which was successfully launched on 23 July 2020; the probe entered the Martian orbit on 10 February 2021 and released the Zhurong rover for landing about 3 hr before its touchdown (Li et al., 2021;Wan et al., 2020;Wu et al., 2021). The Zhurong rover landing represents the tenth in situ investigation of the Martian surface and the first in the lowland area of southern Utopia Planitia. Using the scientific payloads onboard the Zhurong rover (Li et al., 2021), including the Navigation and Terrain Camera (NaTeCam), Multispectral Camera (MSCam), Mars Surface Composition Detector (MarSCoDe), Mars Rover Penetrating Radar (RoPeR), Mars Rover Magnetometer, and Mars Climate Station, the Zhurong rover will investigate the topography, soil structure and geology of the roving area and the physical characteristics of the atmosphere. The rover will also analyze elements, minerals and rock types and search for signatures of water or ice in the roving area (Li et al., 2021;Zou et al., 2021).The landing site selection process for Zhurong included several stages. In the first stage, a global search process was conducted on the Martian surface to identify suitable regions that met the engineering constraints, including adequate solar illumination for generating power and warmth, lower elevation for a thicker atmosphere and longer deceleration time, and a flat terrain surface for safer landing (Dong et al., 2019;Wu et al., 2021). Three

Photogrammetric Processing of Tianwen-1 HiRIC Imagery for Precision Topographic Mapping on Mars

“…It should be noted that, no ground control points are involved in both the bundle adjustment and block adjustment processes. A number of reference points extracted from a CTX image mosaic [3] covering the study area are used to adjust the planimetric positions of the HiRIC images during the RPC generation. In the subsequent bundle/block adjustment, the MOLA DEM is regarded as the reference datum so that the space intersection of the tie points coincide with the MOLA elevations in local areas.…”

“…Since the Tianwen-1 probe entered the Mars orbit in February 2021, intensive studies of the candidate landing site in southern Utopia Planitia have been conducted using data from the HiRIC and other sensors [3]. With an approximately 300km orbit height, the HiRIC image resolution can reach 0.7 > REPLACE THIS LINE WITH YOUR MANUSCRIPT ID NUMBER (DOUBLE-CLICK HERE TO EDIT) < m/pixel, which allows high-resolution mapping to reveal the detailed topography.…”

“…As no ground control point measured from MOLA is leveraged in the block adjustment to register the HiRIC orbit strictly, the process is still a free network block adjustment. 8 presents a side-by-side comparison of the generated HiRIC DEM and the MOLA DEM, revealing an overall smooth slope down to the north and providing a suitable place for rover landing [3]. The 3D information of distinct landforms (i.e., the large craters, a series of dunes, and ridges) is properly reconstructed.…”

“…HINA'S first Mars probe, the Tianwen-1 carrying the Zhurong rover, was launched in July 2020, entered the Martian orbit in February 2021, and successfully landing Zhurong in southern Utopia Planitia on May 15, 2021 [1], [2], [3]. From mid-February to early May 2021, the Tianwen-1 orbiter performed detailed investigations of the potential landing region in southern Utopia Planitia using its onboard instruments.…”

“…The work was also supported by grants from the Research Grants Council of Hong Kong (RIF Project No: R5043-19, Project Nos: PolyU 15210520, PolyU 15219821). (Corresponding author: Bo Wu) topographic mapping to facilitate the selection of the best landing site for the Zhurong rover [3] and provide data support for various scientific studies [4].…”