The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a clearance measuring device for the hemisphere dynamic pressure motor is designed, which improves the measurement efficiency and stability.

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.

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.

China’s commercial space activities started from the launch of Asiasat-1 satellite by a LM-3 launch vehicle on April 7, 1990. As the leading force in China’s space industry, CASC has been committed to commercial space for nearly 30 years. The article describes CASC’s advantages and activities in commercial space sector, as well as outlook for CASC commercial space development. The author concludes CASC is willing to coordinate and cooperate with state-owned and private companies and will create a new pattern for commercial space, opening up a new industry for space development and achieving more splendid achievement.

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 space industry has been developed quickly and consistently setting new records for mankind in space exploration in the past 60 years. Four principles are upheld during its development. Systems engineering and overall thinking have played an important role in the development of China’s space industry. What’s more, the concept of systems engineering which originated from the space industry, being rooted in society, is a successful example of “Chinese theory” answering “Chinese question” and “Chinese wisdom” guiding “Chinese development”, which is a trump card for the country and provides a unique business governance mode with Chinese characteristics.