China's first Mars rover, Zhurong, is pictured next to its landing platform on the surface of the red planet. The rover traveled approximately 10 meters to drop off a wireless camera, then backed up into frame in order to capture this spectacular image
The main components on the Rover are listed as follows
- Mars Rover Penetrating Radar (RoPeR) Ground-penetrating radar (GPR), two frequencies, to image about 100 m (330 ft) below the Martian surface[26] It was one of the two very first ground-penetrating radars deployed on Mars, along with the one equipped by NASA's Perseverance rover launched and landed in same years.[63]
- Mars Rover Magnetometer (RoMAG) obtains the fine-scale structures of crustal magnetic field based on mobile measurements on the Martian surface.
- Mars Climate Station (MCS) (also MMMI Mars Meteorological Measurement Instrument) measures the temperature, pressure, wind velocity and direction of the surface atmosphere, andas a microphone to capture Martian sounds. During the rover's deployment, it recorded the sound, acting as the second martian sound instrument to record martian sounds successfully after Mars 2020 Perseverance rover's microphones.
- Mars Surface Compound Detector (MarSCoDe) combines laser-induced breakdown spectroscopy (LIBS) and infrared spectroscopy[64]
- Multispectral Camera (MSCam) Combined with MarSCoDe, MSCam investigates the mineral components to establish the relationship between Martian surface water environment and secondary mineral types, and to search for historical environmental conditions for the presence of liquid water.
- Navigation and Topography Cameras (NaTeCam) With 2048 × 2048 resolution, NaTeCam is used to construct topographic maps, extract parameters such as slope, undulation and roughness, investigate geological structures, and conduct comprehensive analysis on the geological structure of the surface parameters.
The paper states that the Mars rover carries the Mars Surface Composition Detector (MarSCoDe) to explore the surface composition of Mars. The instrument uses laser-induced breakdown spectroscopy (LIBS) to obtain high-resolution spectral characteristic information in the ultraviolet to the near-infrared spectrum of the target plasma, and analyzes the chemical element composition of the material on the surface of Mars. It also uses short-wave infrared spectroscopy (SWIR) to obtain the reflection spectrum data of the specified target point and analyze the mineral composition of the soils and rocks.
Laser emission and focusing: shaping and expanding the beam emitted by the laser and focusing the beam to a spot with a diameter of <300 μm at different working distances from 1.6 to 7 m to meet the requirements of the laser power density for creating the plasma of target;
Transmitting and receiving the laser for ranging and autofocus: The 1550-nm continuous laser emitting from a single-mode fiber is transmitted by OHU to the target. The laser energy scattered by the target is collected via the telescope of OHU and transmitted to the signal processing system to implement ranging and autofocus function.
To withstand the Martian environment and large vibration loads, the optomechanical design of the Optical Head Unit was stressed by the paper as the key to the success of the optical components.
To balance optical performance maintenance under low temperature and the mechanical performance of OHU, some specific designs were applied to key modules such as the primary mirror and the optical bench.
For the design of the primary mirror, the fully open structure and semi open structure were studied and compared using simulation and experiment. The semi open design was found to significantly improve the structural rigidity and optical performance of the primary mirror.
For the optical bench, comparing design, processing, and final performance of the optical benches based on three materials was conducted.
The advantages and difficulties of SiC, C/SiC, and CFRP materials used for an optical bench of small and compact optomechanical systems were examined.
Verified by various experiments, the OHU achieved the required performance after vibration and also in a large working temperature range from −60°C to 30°C, surviving in the temperature range from −120°C to 50°C.
“Design and material selection of optomechanical systems for the extreme environment on Mars”
Yichao Yang, Zhixin Yan, Jiayi Shen, Yaowu Kuang, Wenzhi Wan, Jianjun Jia, Chongfei Liu, Jun Chen, Botao Wang, Tao Bao, Zhenqiang Zhang, Weiming Xu, Rong Shu
Journal of Astronomical Telescopes, Instruments, and Systems Vol. 7, Issue 3 (Aug 2021)