Throttling of large-thrust liquid rocket engines, which can improve mission adaptability of a carrier rocket, reduce risk and facilitate rocket recovery, is a key technology for current and future space development. This paper summarizes the state of the art and trends of throttling technology for large-thrust liquid rocket engines at home and abroad. According to the working principles of propulsion for rocket engines, throttling the propellant flow rate is a major way of adjusting thrust, and regulation devices along with adjustable injectors are primary measures of throttling propellant flow rates. This paper clarifies the working principles of typical regulation devices and adjustable injectors, introduces the regulation schemes of typical large-thrust engines such as YF-100, RD-170, and SSME, and summarizes the main characteristics of current throttleable large-thrust engines. Finally, critical technologies and development trends of throttling are discussed, including combustion stability and reliable cooling of thrust chambers at low thrust levels, turbopump stability, and stable regulation and precise control in a wide range of operating conditions.

This paper reviews the recoverable satellites China has developed over the past forty years. The main missions, technical specifications, scientific and technical experiments of these satellites, including the SJ-10 scientific experiment satellite launched on April 6, 2016 are introduced. Recommendations for future technical upgrades for recoverable satellites are also proposed in the paper.

In this paper, to meet the environmental requirements for the lunar surface, we outline the design of an intelligent shape memory polymer (SMP) capsule structure of lightweight using a flexible composite skin. Key breakthrough technology for manufacturing the high-performance multilayer composite is utilized to realize the requirements for folding and compressing during launching, and unfolding on the lunar surface, taking into account the current opposing requirements for launching and the space transportation mission of large equipment. Based upon the reduced constraints, better expansibility and easy assembly, this lunar base is suited to the initial and interim phases of a moon construction, and provides a national solution in the construction of lunar base on moon.

As the closest celestial body to the Earth, the moon is a hot spot for international space science research at present. Countries around the world have conducted lunar exploration time after time, among which, China’s Lunar Exploration Program has achieved 6 consecutive successful lunar missions. China has made a series of significant achievements in deep space exploration, and its cooperation with international partners is increasingly strengthened. 
In order to gather global space power and scientists’ wisdom, the International lunar Research Station (ILRS) is proposed by China and will be jointly constructed by many countries, which will be equipped with the support capabilities of energy supply, central control, communications and navigation, space-Earth round-trip transportation, lunar surface scientific research, and ground support. All international partners are encouraged to jointly develop and build the ILRS, and to jointly initiate the establishment of the International Lunar Research Station Cooperation Organization (ILRSCO) to achieve the long-term effective, operation and management of the station. The vast universe sparks the exploration dream of humankind, so let’s set sail together.

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.

Satellite laser ranging (SLR) is an unambiguous measurement technique and generates high accuracy satellite orbit data. All satellites in the BeiDou navigation satellite system (BDS) carried laser retro-reflector arrays (LRAs), so they can be tracked by ground SLR stations in order to provide the accurate observation data. The Shanghai astronomical observatory (SHAO) designed the LRAs, and also developed the dedicated SLR systems using a 1 m-aperture telescope and a transportable cabin-based SLR system with a telescopes of 60 cm aperture. These enable BDS satellite ranging during daytime and nighttime with centimeter-level precision, allowing highly accurate estimations of satellite orbits. Moreover, some of the BDS satellites are also equipped with laser time transfer (LTT) payloads, which were developed by the SHAO and China Academy of Space Technology (CAST), providing a highly accurate time comparison between the satellites and ground clocks. This paper describes the dedicated SLR system and the design of the LRAs for BDS satellites, as well as global SLR measurements. The SLR tracking data is used for evaluating the orbit accuracy of BDS satellites and broadcast ephemeris, with an accuracy of less than 1 m. The LTT measurements to BDS satellites for a single shot have a precision of approximately 300 picoseconds, with a time stability of 20 picoseconds in 500 s.

At 00:25 Beijing time on January 20, China launched the Tiantong 1-03 satellite onboard a LM-3B carrier rocket from the Xichang Satellite Launch Center. The satellite entered its preset orbit, marking the success of China’s first launch mission in 2021. 
The Tiantong 1 satellites were developed by the China Academy of Space Technology, of which the Tiantong 1-01 and 1-02 satellites were launched by LM3B in 2016 and 2020 respectively. The Tiantong 1-03 satellite will be networked with the previous two satellites, realizing China’s autonomous and controllable satellite mobile communications system that can cover the Asia-Pacific region.
The LM-3B carrier rocket was developed by the China Academy of Launch Vehicle Technology.
This was the 358th launch of the LM series launch vehicle and the 117th launch of the LM-3 family.
CASC plans to conduct more than 40 launch missions in 2021.

The solid rocket motors for the escape system of China’s LM-2F manned launch vehicle are described, the key technologies and technical innovations utilized are summarized. The technical features and development of foreign manned launch abort systems are also presented. The development trends of the solid rocket motor for future Chinese manned launch vehicle escape systems are proposed, which can provide a reference for the future development of manned launch vehicle escape systems.

Acknowledged as a highly versatile manufacturing technology, additive manufacturing holds the potential to transform traditional manufacturing practices in the future. This paper provides a comprehensive review of the latest processes for manufacturing multi-material structural components using additive manufacturing technologies. It discusses the most recent applications of these processes in the fields of automotive, aerospace, biomedical, and dental, and presents a systematic overview of commonly used methods in multi-material additive manufacturing.

Based on international requirements for the application of commercial remote sensing data, an information service system for receiving and processing multi source remote sensing data was developed and introduced. The system consists of an Oversea Fixed Ground Service Station (OFGS), a Transportable Vessel-Borne Service Station (TVBS) and a Data Operation and Management Center (DOMC). Fixed and transportable service stations were developed in Venezuela, Latin America and for the China’s Xuelong polar research vessel respectively, and serve the function of remote sensing data receiving, processing and application. The DOMC connects the OFGS and TVBS, so that they constitute a network to provide receiving, distribution, retrieval, browsing, ordering, and downloading functions for multi remote sensing satellite data and products. It validates the competence in providing 40 kinds of typical application products. The development of this system provides a reliable and comprehensive service for commercial remote sensing data applications for users both in domestic and oversea markets.

Hall thruster is a type of electric propulsion thruster which is often regarded as a moderate specific impulse space propulsion technology and is used primarily for station keeping and orbit maintenance tasks. Magnetic field is the most important aspect in Hall thruster’s design. Each time the performance improvement of Hall thrusters is accompanied with the regeneration of magnetic field design. Now, all the major space nations treat the magnetic field design as the key technology for Hall thrusters, and many Hall thrusters have emerged in recent years, for example, BPT-4000 and NASA-173M. In China, based on magnetic focus technology, the Beijing Institute of Control Engineering (BICE) has been developing Hall thrusters ranged from hundreds of watts to 5 kilowatts, including the 1500 W HEP-100MF and the 5 kW HEP-140MF Hall thrusters. This paper briefly reviews the development of the HEP-XXMF series Hall thruster. The principle of the Hall thruster, the design methods and the current status of HEP-100MF and HEP-140MF are discussed in the paper.

According to the different types and characteristics of satellite fault, a kind of fault diagnosis method is proposed, which integrates multivariate threshold, model-based and fault tree-based method. In order to optimize the fault diagnosis method, it takes the advantages and remedy of a defect with other methods. This can diagnose many kinds of satellite fault occurring in the on-orbit phase rapidly and accurately. Besides, it can analyze the damage degree of the failure and establish the measures to eliminate the failure.

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.

This paper introduces the autonomous control technologies for a new generation launch vehicle for guidance and attitude control. Based on the iterative guidance mode (IGM) of Long March launch vehicles, the autonomous compensation IGM (ACIGM) for the terminal attitude deviation during the coasting phase is proposed. Considering the characteristics of large static instability and weak bearing capacity, the attitude control technology based on active disturbance rejection control (ADRC) and a control method based on an accelerometer are proposed. Targeting at non-fatal failures that may occur during flights, autonomous guidance reconstruction technology, nozzle fault diagnosis and reconstruction technology in the coasting phase are studied. Some of the autonomous control technologies proposed in this paper have achieved good control results as seen through flight verification.

The LM-6A new generation solid-liquid strap-on launch vehicle has the structural dynamic characteristics of lower frequencies, denser modes and coupling modes in longitudinal, bending and torsion modal space. During the development phase of LM-6A, modal tests of partial stacks and the full vehicle were designed to obtain the structural dynamic properties. The structural dynamic models using the finite element method (FEM) have been verified and calibrated based on the modal test data. This paper describes the pre-test predictions and test execution, and details the comparison between the pre-test predictions and the test data. The successful maiden flight of LM-6A further confirmed the effectiveness of structural dynamic modeling and modal test for LM-6A.

The International Lunar Observatory Association (ILOA) is an inter-global enterprise incorporated in Hawai’i as a non-profit organization in 2007 to advance human understanding the cosmos through observation of the moon, helping to realize long-term astronomical and scientific exploration of the moon’s South Pole, and participate in a human lunar base build-out — with Aloha. ILOA has an international board of 28 Directors from around the world. 
Science education and public engagement have been fundamental principles for ILOA since its inception in 2007.

With the rapid development of intelligent connected vehicles, high-precision 3D navigation has become a key supporting technology. This article conducted a series of drive tests using the high-precision navigation technology of BeiDou and BeiDou+5G hybrid positioning technology, aiming to verify the positioning performance in complex highway traffic environments. The test was conducted on actual roads in Beijing and Hangzhou showed that the positioning accuracy of BeiDou high-precision navigation reached a real-time centimeter level, with a fixed rate of about 95% and a convergence time of less than 2 s. The elevation accuracy of BeiDou+5G hybrid positioning was better than 0.2 m. Combined with three-dimensional high-precision laser point cloud maps, the overlay verification showed that the model can support three-dimensional lane level navigation, verifying the application potential of BeiDou high-precision positioning and BeiDou+5G hybrid positioning technology in the fields of autonomous driving and intelligent connected vehicles.

This paper proposes a multi-UAV cooperative exploration approach based on task-density space partition. In the research of multi-UAV cooperative exploration, it is a prevalent cooperative scheme to control robots to work independently in partitioned spaces. Nonetheless, only considering the position of robots during space partition cannot effectively ensure the overall cooperative efficiency. According to research on task density of current time points and positions of robots during exploration, robots with fewer task points are assigned to work in spaces with more tasks in the rolling horizon optimization planning mode, which can reduce the redundancy of multi-robot cooperative work. Comparative research suggests that the overall exploration efficiency is improved.

The Smart Dragon 1 (SD-1) launch vehicle is the first commercial rocket developed by China Academy 
of Launch Vehicle Technology (CALT), targeting to the international launch market for small satellites. As the smallest launch vehicle in China at present, SD-1 is one of the most efficient solid boost rockets nationwide in terms of launch capacity. Compared with current domestic rockets, it provides remarkable access to space with a faster response, higher orbit-injection accuracy and better payload accommodation at a lower cost. On August 17, 2019, SD-1 completed its maiden flight and delivered three satellites into the desired Sun Synchronous Orbit (SSO) of 550 km accurately. In this article, a technical review of SD-1 is presented detailing the design concept and the use of state of the art technology throughout its development.

Reusable launch vehicle is an important way to realize fast, cheap and reliable space transportation. A combined cycle engine system provides a more efficient and flexible form of power. The investigation on the research status of the combined cycle engine technology, including basic principle, research programs and classification of structure is firstly discussed in this paper. Then the bilevel hierarchical and integrated parameters/trajectory overall optimization technologies are applied to improve the efficiency and effectiveness of overall vehicle design. Simulations are implemented to compare and analyze the effectiveness and adaptability of the two algorithms, in order to provide the technical reserves and beneficial references for further research on combined cycle engine reusable launch vehicles.

At an accelerating development pace, Micro-Nano Satellite technology has become one of the most active research topics in the current aerospace field. Its applications have been extended from engineering education and technology demonstration into various other fields, such as communication, remote sensing, navigation and scientific experiments just to name a few. In this paper issues raised on Micro/Nano-Satellites in recent news are reviewed and the opportunities and challenges confronting Micro/Nano-Satellites are analyzed. Then the Micro/nano-Satellites of National University of Defense Technology (NUDT) are briefly introduced. Finally, some suggestions on the development of Micro/Nano-Satellites in the future are proposed.