Entry vehicle control system design for the Tianwen-1 mission

The entry vehicle for the Tianwen-1 mission successfully landed on the surface of Mars at 7:18 AM BJT on May 15, 2021. This successful landing made China the first country to orbit, land, and release a rover in their first attempt at the Mars exploration. The guidance, navigation, and control (GNC) system plays a crucial role in the entry, descent, and landing (EDL) phases. This study focused on the attitude control component of the GNC system design. The EDL phase can be divided into several sub-phases, namely the angle of attack control phase, lift control phase, parachute descent phase, and powered descent phase. Each sub-phase has unique attitude control requirements and challenges. This paper introduces the key aspects of designing attitude controllers for each phase. Furthermore, flight results are presented and analyzed.

End-to-end Mars entry, descent, and landing modeling and simulations for Tianwen-1 guidance, navigation, and control system

On May 15, 2021, the Tianwen-1 lander successfully touched down on the surface of Mars. To ensure the success of the landing mission, an end-to-end Mars entry, descent, and landing (EDL) simulator is developed to assess the guidance, navigation, and control (GNC) system performance, and determine the critical operation and lander parameters. The high-fidelity models of the Mars atmosphere, parachute, and lander system that are incorporated into the simulator are described. Using the developed simulator, simulations of the Tianwen-1 lander EDL are performed. The results indicate that the simulator is valid, and the GNC system of the Tianwen-1 lander exhibits excellent performance.

Powered-descent landing GNC system design and flight results for Tianwen-1 mission

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.

Peer review declaration

All papers published in this volume of Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing. • Type of peer review: Double-blind • Number of submissions received: 27 • Number of submissions sent for review: 17 • Number of submissions accepted: 17 • Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 17/27*100 = 62,96% • Average number of reviews per paper: 2 • Total number of reviewers involved: 9 Any additional info on review process: We usually use single-blind type of PR, but also in controversial cases we can use double-blind. This year we sent the paper to the reviewer for 2 weeks to make a review. Then authors made some improvements in their papers. If there was any doubt about acceptance or rejection after this step, we asked the third reviewer to analyze and make a decision. Editor rechecked the revised papers based on the gathered reviews, proofread the texts made in the Word template, edited the manuscript if needed, and checked the similarity before submitting papers in IOP. All papers meet the Technical Criteria, Quality Criteria, Presentation Criteria set by IOP Publishing. Aims and scope • Gyroscopic systems • Applied problems of navigation and motion control • Sensors for navigation and control systems • MEMS sensors, systems, and technologies • Data processing in navigation systems • Integrated and satellite navigation systems • Control theory and control systems • Electronic and electromechanical devices of navigation and control systems The aim of the workshop is to provide an overview of new technologies in navigation and motion control. The program includes tutorials on modern navigation and control systems as well as hardware design problems, which will be delivered both by the leading Russian and foreign scientists and young scientists. Contact person for queries: Dmitry O. Taranovskiy, PhD, head of editorial group Concern CSRI Elektropribor, JSC, editor’s office, St. Petersburg, Russia [email protected]

The Tianwen-1 Guidance, Navigation, and Control for Mars Entry, Descent, and Landing

Tianwen-1, the first mission of China’s planetary exploration program, accomplished its goals of orbiting, landing, and roving on the Mars. The entry, descent, and landing (EDL) phase directly determines the success of the entire mission, of which the guidance, navigation, and control (GNC) system is crucial. This paper outlines the Tianwen-1 EDL GNC system design by introducing the GNC requirements followed by presenting the GNC system architecture and algorithms to meet such requirements. The actual flight results for the whole EDL phase are also provided in this paper.