This paper first introduces the technical requirements for autonomous flight, with a brief review of the International Academy of Astronautics (IAA) study group, “autonomous dynamic trajectory optimization control of launch vehicle”. Two research scenarios, ascent rescue and powered descent, are compared from the viewpoint of optimal control. On this basis, the technologies on the autonomous trajectory planning and control under the thrust-drop failures in the ascending phase, and the autonomous guidance method during the powered landing for the recovery of the rockets are discussed respectively. For the ascending problem, the characteristics of different solutions, including the iterative guidance method (IGM)-based residual carrying capacity evaluation, the state-triggered indices (STI), the joint planning with the payload’s performance, and the multiple graded ptimization (MGO), are analyzed for comparison. For the landing problem, the challenges such as the feasible region reduction caused by high thrust weight ratio (HTWR) and the disturbance adaptability brought by the limited feasible region, are studied in detail, as well as the onboard planning demonstration flight in China are introduced. Finally, the foundations supporting the above methods are summarized, which play an important role in promoting the flight autonomy.

Large constellations have developed rapidly in recent years because of their unique advantages, but they will inevitably have a major negative impact on the space debris environment, leading to its deterioration. The key to mitigate the impact is the success rate and duration of the post-mission disposal (PMD) process. Aiming at solving this problem, this paper further studies the impact of large constellations on other space assets under different PMD strategies through simulation, and proposes corresponding strategies and suggestions for mitigation.
According to OneWeb’s large constellation launch plan, the dangerous intersection of the large constellation with existing space assets at different stages of the constellations life cycle is calculated by simulation. Based on this, the influence of the large constellation operation on existing space assets at different times and strategies of PMD is analyzed. The conclusion shows that in the PMD stage, large constellations have the greatest impact on existing space assets; the PMD duration and number of satellites performing PMD at the same time are key factors to the degree of negative impact. The faster the PMD is, the less threat it poses to other spacecraft. More results and conclusions are still being analyzed.

Liquid propellant rocket engines for a launch vehicle are an essential aerospace technology, representing the advanced level of hi-tech in a country. In recent years, China’s aerospace industry has made remarkable achievements, and liquid rocket engine technology has also been effectively developed. In this article, the development processes of China’s liquid rocket engines are discussed. Then, the performance features of China’s new generation liquid rocket engines as well as the flight tests of the new-generation launch vehicles are introduced. Finally, the development direction and the most recent progress of the next generation large-thrust liquid rocket engine is presented.

High power Hall electric propulsion technology is a very competitive electric propulsion technology for future large space missions such as large GEO satellites, manned space programs, deep space explorations, cargo ships, space tugs. Based on the experience of more than 20 years in research and development of Hall electric propulsion, the Shanghai Institute of Space Propulsion (SISP) has developed 3 high power Hall thrusters, i.e., the 10 kW class HET-500, 20 kW class HET-1000, and 50 kW class HET-3000. This paper presents the development status of the high power ( ≥ 10 kW) Hall electric propulsion at SISP, including tests of 3 high power Hall thrusters in the power range from 10 kW to 50 kW, the qualification of a single string of a 10 kW Hall electric propulsion system, and the study of a cluster of two 1.35 kW HET-80 Hall thrusters to understand the technical issues related to multi-thruster high power electric propulsion systems.

Why has the sun burnt for billions of years? What is the mechanism of combustion? What will happen to the trend of solar combustion? Modern humans have only just begun their close-up exploration of the sun. By studying the sun, we can learn more about other stars. The more we understand other stars, the more we will know about the universe in the end. The exploration of the origin of solar energy will help people to deepen their understanding of the origin of the universe as well as the development of the universe. Solar probes will help us further understand the characteristics of the sun, validate relevant theories and make new discoveries.