摘要
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.
基金
This work was supported by the National Natural Science Foundation of China(Grant Nos.61673057 and 61803028)and the Civil Aerospace Advance Research Project.
