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.

The GF-3 satellite, the first C band and multi-polarization Synthetic Aperture Radar (SAR) satellite in China, achieved breakthroughs in a number of key technologies such as multi-polarization and the design of a multiimaging mode, a multi-polarization phased array SAR antenna, and in internal calibration technology. The satellite technology adopted the principle of “Demand Pulls, Technology Pushes”, creating a series of innovation firsts, reaching or surpassing the technical specifications of an international level.

Traditionally RF power amplifiers used Gallium Arsenide (GaAs) technology which has a well behaved and understood performance. Over the past few years Gallium Nitride (GaN) technology is replacing GaAs because GaN is 
more efficient and has a higher power density resulting in higher power MMICs and FETs.
Subject to system link budgets, we usually want to run a given amplifier as close to saturation as possible to minimize CAPEX costs. Running an amplifier closer to saturation causes many non-linear effects that can cause link performance degradation and interfere with other users.
To better understand and quantify the differences between GaN and GaAs amplifiers and the impact of this on system performance, some amplifier and system measurements will be taken. The findings will be documented in a white paper.

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.

Upper stage is an indispensable vehicle in the space transportation system. For its role in multi-satellite transportation area in China, the development of the Yuanzheng 3 upper stage was approved. The article introduces in detail the Yuanzheng 3 upper stage development requirements, task definition and systems as well as main features and performance including payload capacity and insertion accuracy for typical orbits, interfaces with satellites. The article also presents the development cycle of Yuanzheng 3 upper stage, which is divided into 3 stages including concept demonstration stage, prototype stage and flight proof stage. The Yuanzheng 3 upper stage, which will make its maiden flight in 2018, is capable of restarting more than 20 times, and operating for more than 48 hours. It is equivalent to mainstream upper stages in the world in terms of performance, such as restart times, in-orbit operation time, independent digital control system, and adaptable behavior for various tasks. Technologies tackled and accumulated in the development of the Yuanzheng 3 upper stage will lay a solid foundation for the development of future space transportation vehicles.

SuperView-1 satellite constellation (SuperView-1 for short) is the first commercial remote sensing constellation with a resolution down to 0.5 m. It’s an important part of the national spatial information infrastructure construction. It will play an important role for the global users providing remote sensing data, application solutions and remote sensing value-added services with its high-resolution and 24-hour observation capability. At present, 4 satellites of the constellation have been successfully launched and networked on orbit. The services cover surveying and mapping, land resource surveying, urban planning, agriculture, forestry, water conservancy, geological mining, environmental monitoring, defense, disaster reduction along with other traditional industries. There are also great potential applications in Mobile Internet, LBS, Smart city, insurance and other emerging professions. The successful operation of SuperView-1 
breaks the overseas monopoly for commercial high-resolution remote sensing satellite imagery in the China market. 
It’s one of the major achievements in China space science and technology by actively exploring the development of commercial remote sensing markets, which is of strategic significance to the development of China remote sensing satellite business.

China’s new-generation launch vehicle LM-5 successfully completed its maiden launch in November 2016. Among the new technologies applied in the launch vehicle, four types of liquid rocket engines attracted extensive attention. These engines feature advanced concepts and technologies such as a staged combustion cycle and expander cycle. The engines are the results of hard effort of more than ten years, which is also an epitome of the development history of China’s aerospace industry. This paper gives a brief introduction to the technological schemes, main parameters, development process and application of the four types of engines that powered the new-generation launch vehicle. Finally, proposals for new liquid propulsion technology development in the future in China are 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.

Queqiao relay communications satellite was developed to provide relay communications services for the lander and the rover on the far side of the moon. From entering into its halo mission orbit around the Earth-moon libration point 2 on June 14, 2018, it has operated on orbit more than fifteen months. It worked very well and provided reliable, continuous relay communications services for the lander and the rover to accomplish the goals of Chang’e 4 lunar far side soft landing and patrol exploration mission. The on-orbit operation status of Queqiao relay communications satellite is summarized in this paper.

Heavy launch vehicles represent the ability of a country to enter space and utilize space resources. In recent years, with the growth in human space exploration, the major aerospace powers and companies in the world are planning to develop heavy launch vehicles. This study analyzes the development of heavy launch vehicles in the world, reviews the characteristics of China’s heavy launch vehicle serial configuration, and then proposes common points and development trends of future heavy launch vehicles in the world.

Over the next decade,Very High-Throughput Satellite (VHTS) will bring enough capacity to serve high speed internet and in-flight connectivity markets at scale, offering fiber-like services both in terms of price and speed. In this context, a generic VHTS mission utilizing Q/V-band feeder links and Ka-band user links is described. However, the rain attenuation on the feeder links becomes a limiting issue because of the higher frequencies. Toward this, an exploitation of multiple gateways (GWs) as a transmit diversity measure for overcoming severe propagation effects are being considered. Ground Application System (GAS) design of VHTS is illustrated including N+P GWs (N active and P redundant GWs) diversity, frequency plan, link budget and system capacity.

The divergence angle of laser beam used in space laser communication is usually no more than 100 μrad. Using laser beam with small divergence angle to achieve acquisition and tracking for space laser link has al-ways been a difficult problem. In addition, the random nature of the atmosphere will affect the satellite-ground laser link, which increases the difficulty of the acquisition and stable tracking for the laser link. Thus, taking into account the above challenges for satellite-ground laser communication, an acquisition and tracking scheme of using both beacon beam and signal beam was designed for the Laser Communication Terminal (LCT) of Shijian 20 satellite. In-orbit test results indicated that under the condition of moderate atmospheric turbulence (atmospheric coherence length r0≈3cm), the process of acquisition and tracking for the satellite-ground laser link can be completed within 1s after the initial pointing between the LCT and Optical Ground Station (OGS) is performed, and the tracking error was less than 1 μrad (3σ). In addition, the laser link can be re-established quickly once being interrupted by unsteady atmospheric turbulence, and can be maintained for a long time under moderate twurbulence conditions, which lays a foundation for future application of satellite-ground laser communication.

With the development of large numbers broadband Internet access, global satellite communications is moving towards High Throughput Satellites (HTS). Now, USA, Canada, Europe, Thailand, Japan, United Arab Emirates, Australia have already developed HTS systems. However, there is little research to analyze the factors influencing high throughput. Thus, from the design perspective, the throughput of HTS and influencing factors are calculated and compared at a system level. Finally, the application of HTS is analyzed and forecasted.

The Space Power Satellite (SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glaser in 1968. SPS have been studied now for exactly fifty years by many scientists in various countries. It has been regarded as one of the most promising energy projects of the future and has been attracting more attention in recent years. More and more Chinese scholars and experts are paying attention to the development of SPS. Due to the huge size, immense mass and high power of such a satellite system, there are many technical difficulties which exist to realize SPS. In this paper, recent SPS research and development activities are reviewed first. Various SPS concepts are analyzed and compared. The primary scheme of the Multi-Rotary joint SPS (MR-SPS) is described. The main feature is that the huge solar array comprising many separate small solar sub-arrays and each solar sub-array has two middle power rotary joints. So, the most challenging technology, the high-power rotary joint, is simplified by using many middlepower rotary joints hence the possibility of a single-point failure of a single rotary joint is avoided. This enables easy assembly of the modular solar arrays. Finally some key technologies of MR-SPS are analyzed.

For the last 10 years, the Venezuelan aerospace industry has been constantly growing, and it is to be expected to continue in the same way in the future. China and its space industry, as the main partner for most of the ongoing Venezuelan space projects from their beginning, has been an important player in their development and may continue acting as one of the most important partners not only for the Venezuelan aerospace industry but also for other Latin-American countries’ aerospace industries.
ABAE (Bolivarian Agency for Space Activities) together with the related Chinese aerospace companies, with the guidance and help of CGWIC, has been constantly improving its cooperation methods, regarding technical work flows as well as management activities, especially for the latest’s space projects under development, namely the CIDE (Venezuelan Design, Assembly, Integration and Testing Center) and VRSS-2 (Venezuelan Remote Sensing Satellite-2) programs. Provided that there is a deeper and stronger cooperation in the future, partnership and friendship of the different scientists, experts and leaders from the space sectors of both countries, will be improved and strengthened for the development of both nations social welfare.

In the history of human space exploration, many failures of launch vehicles and spacecraft tare caused by vibration. At first, the periods in which the space products are in a vibration environment are discussed and the need for vibration testing is then introduced. As the main content of this paper, the current situation of shaker systems is elaborated in detail. In this part, electrodynamic shakers, as the most widely used vibration generators, are illustrated in detail including structures, principles and performances. Special inventions worldwide in the development of electrodynamic shakers such as induction ring shakers, high force shakers, multi-axial vibration testing systems and combined environmental testing systems are presented. At last, the recent progress and outlook of shaker systems are summarized.

In this paper, we examine the interrelation between innovation and commercial marketing using the DFH-4 series bus satellite as an example which customers are familiar with. Strategies in evolving satellite buses and key subsystem technologies without compromising on advanced innovations, favorable heritage and thorough verification are also discussed. Market development experiences with the DFH-4 series bus satellite are summarized and market recognition is reflected from the space insurance perspective.

Space is becoming more accessible than ever before. Falling satellite manufacturing and launch costs have opened the door to new players to enter the market, disrupting the status quo. HTS and constellations have entered the market and will lead to a lot more capacity at a lower price. But how this capacity will be optimally distributed remains a significant challenge. Earth Observation (EO) and Big Data are also areas of interest that are gaining grounds thanks to projects of 100s if not 1,000s of satellites that will have a lasting effect on manufacturing and launch markets.

The Staring Area Imaging Technology (SAIT) satellite continuously “images” the target over a certain time range, and can realize continuous imaging and multi-angle imaging of the area of interest. It has the characteristics of flexible imaging parameter setting and fast image preprocessing speed, enabling dynamic target detection and tracking, super-resolution, surface 3D model construction, night-time imaging and many other application tasks. Based on the technical characteristics of the SAIT satellite, this paper analyzes the challenges in satellite development and data processing, focuses on the quasi-realtime application of SAIT satellite data, and looks at the development trend of the SAIT satellite.

The Long March 11 launch vehicle (LM-11) is the only solid launch vehicle within China’s new-generation launch vehicle series, enabling a full spectrum of Chinese launch vehicles. Compared with other China’s LM series launch vehicles, it has the shortest launch preparation time. With the characteristics of appropriate launch capability, quick response, easy-to-use, flexible operation, universal interface and strong task adaptability, LM-11 can better meet the launch requirements for various small networking satellite, replacement and for emergency use. After four successful launches, LM-11 has become the main Chinese launch vehicle oriented to the international small satellite commercial launch market.

As human aeronautic and aerospace technology continues to prosper and the aerial flight space domain further expands, traditional fixed-shape air vehicles have been confronted with difficulties in satisfying complex missions in cross-domain scenarios. Owing to their flexible and deformable appearance, morphing air vehicles are expected to realize cross-domain intelligent flight, thus emerging as the most subversive strategic development trend and research focus in aeronautic and aerospace fields. This paper primarily reviews the research background and challenges of flexible and deformable cross-domain intelligent flight, proposing a corresponding research framework and mode as well as exploring the scientific issues and state-of-the-art solutions, where key research progress is introduced. The explorations covered in this paper also provide ideas and directions for the study of deformable cross-domain intelligent flight, which has critical scientific significance in promoting the study itself.

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.

With the further reduction in cost and the increase in bandwidth, as well as the increase in internet applications, satellite communications are gradually shifting from a complementary role to becoming a fully integrated component of terrestrial communications networks. This paper firstly introduces the development of satellite communications, mobile communications and the global space-terrestrial integrated network. We then propose the functional architecture and network architecture for the integration of satellite communications and terrestrial mobile communications based on 5G core networks. Finally, in order to support the network of the future, four key technologies are presented, a space-terrestrial integrated air interface design, a multi-band space-terrestrial integrated transmission waveform design, space-terrestrial integrated switching and routing technology, along with spectrum sharing and interference coordination technology, all necessary for the development of space-terrestrial integrated networks.

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.

FY-4 is the second generation of Chinese geostationary satellite for quantitative remote sensing meteorological application. The detection efficiency, spectral bands, spatial and time resolution have been greatly improved with respect to those of first generation, as well as the radiometric calibration and sensitivity. The combination of multichannel detection and vertical sounding was first realized on FY-4, because both the Advanced Geostationary Radiation Imager (AGRI) and Geostationary Interferometric Infrared Sounder (GIIRS) are on the same spacecraft. The main performance of the payloads including AGRI, GIIRS and Lightning Mapping Imager, and the spacecraft bus are presented, the performance being equivalent to the level of the third generation meteorological satellites in Europe and USA. The acquiring methods of remote sensing data including multichannel and high precision quantitative observing, imaging collection of the ground and cloud, vertical observation of atmospheric temperature and moisture, lightning imaging observation and space environment detection are shown. Several innovative technologies including high accuracy rotation angle detection and scanning control, high precision calibration, micro vibration suppression, unified reference of platform and payload and on-orbit measurement, real-time image navigation and registration on-orbit were applied in FY-4.

 Recent advances in Artificial Intelligence (AI) have indicated that inspirations from the brain can effectively improve the level of intelligence for AI computational models, even if just local and partial inspirations. Nevertheless, realizing and exceeding intelligence at a human level still needs a deeper investigation and inspirations from the brain. The goal of brain-inspired intelligence is to achieve human intelligence inspired from brain neural mechanism and cognitive behavior mechanism. To this end, in this paper we introduce the relationship between AI and neuroscience, the current status of brain-inspired intelligence, the future work in intelligent control systems, and its profound influence in other fields.

Following the successful maiden flight of the Long March 11 (LM-11) launch vehicle from the Jiuquan Satellite Launch Center in September 2015, the first sea-launched carrier rocket dedicated to provide a launch service for small satellites and their constellations, the Long March 11 Sea Launch (LM-11SL) has been under development by the China Academy of Launch Vehicle Technology (CALT) and the China Great Wall Industry Corporation (CGWIC). It is planned to commence launch service in 2018. Based on the LM-11, a land-launched four-staged solid launch vehicle which has entered the market and accomplished launch missions for several small satellites in the past 3 years, the newly adopted sea launch technology enables transport and launch of LM-11SL from maritime ships, providing flexible launch location selection.
After inheriting the mature launch vehicle technologies from previous members of the Long March launch vehicle family and adopting a new way of launching from the sea, the LM-11SL is capable of sending payloads into low Earth orbits with all altitudes and inclinations, from 200 km to 1000 km, from equatorial to sun synchronous, within a shortduration launch campaign. The LM-11SL provides a flexible, reliable and economical launch service for the global small satellite industry.

The scramjet and maglev engineering technology development and trends at home and abroad are firstly presented in this paper. A new launch mode of space transportation system is proposed based on scramjet and magnetic suspension technologies, and its key technologies required are given. This paper also makes analysis on using scramjet and magnetic suspension technologies to launch a reusable rocket, and the results show that a normal temperature conductor maglev launch system is feasible.

This paper proposes the architecture of an intelligent flight launcher system as well as fundamental solutions to capability prediction and dynamic planning. This effort reflects the latest progress in the applications of intelligent and autonomous technology for launcher flights. The paper first describes the characteristics and capabilities of intelligent and autonomous systems and classifies various related technologies. In the context of intelligent and autonomous technology in aerospace engineering, it then focuses on technical difficulties involved with intelligent flight and reviews developments in the field. An E3 classification model of an intelligent flight launcher is then proposed and its application scenarios are discussed. Based on an intelligent flight system configuration of the launcher, the online trajectory planning and initial value guess are examined, and vertical landing is provided as an example to explain the effects of the implementation of computational intelligence to flight systems.

Two problems were found in recent applications of TRLs in aerospace projects. One is how to accurately evaluate the readiness level of a given technology in a project using the TRL scale. The other is how to deal with the diversity (different types) of technologies involved in an aerospace project. To solve these problems, a technology readiness assessment (TRA) method based on three maturity characteristics is established, and this method is adapted according to the features of different types of technologies. The proposed method has been successfully applied to aerospace projects and enables great effectiveness and accuracy in assessing new technologies.

The far side of the moon is a unique place for some scientific investigations. Chang’e 4 is a Chinese lunar far side landing exploration mission. Relay communication satellite, named as Queqiao, is an important and innovative part of Chang’e 4 mission. It can provide relay communication to the lander and the rover operating on the lunar far side to maintain their contacts with Earth. It was launched by LM-4C launch vehicle at the Xichang Satellite Launch Center on May 21, 2018. After five precise orbit controls and a journey of more than 20 days, Queqiao inserted into final halo mission orbit around Earth-moon libration point 2, located about 65,000 km beyond the moon. It is the world’s first communication satellite operating in that orbit. Up to now, Queqiao worked very well and provided reliable, continuous communication relay service for the lander and the rover to ensure the mission success of Chang’e 4 exploration mission. Via Queqiao, the lander and the rover were controlled to work by ground stations and obtained a great amount of scientific data. The mission overview, operation orbit selection, relay communication system design and flight profile were introduced in this article.

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.

The Long March 5 (LM-5) launch vehicle is China’s new generation heavy-lift rocket with the largest payload capacity, representing the highest standard of China’s current launchers. It took 10 years to develop the LM-5 launch vehicle. On November 3, 2016, the LM-5 carrier rocket blasted off from the Wenchang satellite launch center on Hainan Island, achieving a successful maiden flight. During the development of the LM-5 rocket, the engineering team accumulated abundant experience on developing heavy-lift cryogenic rockets and established a thorough research and development system for new generation launch vehicles, which significantly raised the ability for launcher R&D.

The slow progress and lack of fundamental breakthroughs in legislative practices are an important subject for China’s space legislation. Oriented by the idea to formulate China’s space law as soon as possible, it is necessary to solve five key issues. In the national policy, it is needful not only to implement China’s space policy and promote the development of the space industry in depth, but also to advance the deep integration of military and civil application in space field. In terms of legal orientation, three features should be reflected upon, including the functional integration of public and private laws, the balance of regulation by substantive and procedural laws, and the effective coordination of domestic and international laws. To this end, both top-level design and implementation should be paid close attention to in order to achieve significant progress in China’s space legislation.

Based on the introduction to theresearch status and trend of international space-based laser debris removal technology, the existing problems of space-based laser debris removal technology are systematically analyzed. 
In view of the existing problems, the work and research progress of the Beijing Institute of Spacecraft Environment Engineering in this field are introduced from several aspects, such as dynamic behavior of laser-driven debris, orbit transfer model, ground simulation system, space-based removal system scheme and target selection strategy. The main research methods include laser-driven micro-impulse measurement experiment, surface triangulation three-dimensional reconstruction calculation method based on laser-material interaction theory, simulation calculation based on orbital dynamics, etc. It also looks forward to the future research direction in the field of this technology.

Nano and microsatellites have been widely used in communications, remote sensing, electronics, recon-naissance and other fields, and have become one of the important directions in future aerospace. On the basis of sys-tematically clarifying the concept and scope of the nano and microsatellite industry, this paper analyses the development process of the nano and microsatellite industry. Starting from the nano and microsatellite current development status, this paper summarizes the characters of nano and microsatellites industry professional entities, and then forecasts the trend for nano and microsatellites development in terms of technological development, commercial launching, invest-ment and financing channels.