@article{Huang2022, 
author = {Xiangyu Huang and Chao Xu and Jinchang Hu and Maodeng Li and Minwen Guo and Xiaolei Wang and Yu Zhao and Baocheng Hua and Yunpeng Wang},
title = {Powered-descent landing GNC system design and flight results for Tianwen-1 mission},
year = {2022},
journal = {Astrodynamics},
volume = {6},
number = {1},
pages = {3-16},
keywords = {Tianwen-1, powered-descent landing (PDL), guidance, navigation, and control (GNC), backshell avoidance, hazard avoidance},
url = {https://www.sciopen.com/article/10.1007/s42064-021-0118-9},
doi = {10.1007/s42064-021-0118-9},
abstract = {The powered-descent landing (PDL) phase of the Tianwen-1 mission began with composite backshell—parachute (CBP) separation and ended with landing-rover touchdown. The main tasks of this phase were to reduce the velocity of the lander, perform the avoidance maneuver, and guarantee a soft touchdown. The PDL phase overcame many challenges: performing the divert maneuver to avoid collision with the CBP while simultaneously avoiding large-scale hazards; slowing the descent from approximately 95 to 0 m/s; performing the precise hazard-avoidance maneuver; and placing the lander gently and safely on the surface of Mars. The architecture and algorithms of the guidance, navigation, and control system for the PDL phase were designed; its execution resulted in Tianwen-1's successful touchdown in the morning of 15 May 2021. Consequently, the Tianwen-1 mission achieved a historic autonomous landing with simultaneous hazard and CBP avoidance.}
}