Science and Technology Satellite-3
The satellite-structural technology that can be utilized in various fields of aerospace
"According to this research, it is possible to reduce the weight of the satellite and save the cost required for the launching process by developing the monocoque structure of the satellite, which is made by combining the sandwich panels of the composite materials. Such a structure is different from the previous one of Science Technology Satellite-2, which is made with such components as aluminum sandwich panels and frames. Also, by applying the newly-developed technology to the next-generation satellite, it is possible not only to reduce the cost and the time for the development process but also to increase the level of efficiency. It is expected that by developing such an original technology for the structures of the composite materials, Korea would become one of the most advanced countries in the field of aerospace."
Reduction of the weight of the satellite and the cost for the launching process by using the structures of the lightweight composite materials
Until now, most of the satellite structures have been manufactured by using metallic materials and frames, which have made the structures quite heavy and greatly have increased the cost for the launching process. There have been some reports regarding the use of non-metallic composite materials in other countries. However, there has not been any case of manufacturing the monocoque structure of a satellite by using composite materials in Korea. As a result, it has been impossible to secure the necessary data and technologies required to manufacture such structures. Since it is expected that the application of composite materials for the development of satellites would gradually become more popular in the future, it is necessary to secure these technologies at once.
With such a goal in mind, a research team led by Professor Dai Gil Lee at KIDCS started to focus on the development of the structure for Science Technology Satellite-3 in 2007. The team carried out its research task for the development of the thermal structure sub-system between 2007 and 2010. In the first year of 2007, the team collected its research data for two months, from May to June, and started to focus on the basic design, considering the conditions for the design of the sub-system. Then, in the second year, from July 2007 to January 2008, the team considered the access of the structure and the body of the propulsive system while mainly designing the basic internal/external appearances, selecting the necessary materials, and shaping the heat-controlling sandwich panel made of composite materials. In the third year, from February 2008 to January 2009, the team carried out a preliminary design process for the system and the sub-system and manufactured the initial model for certification.
Also, it made a test product for the heat-controlling sandwich panel made of composite materials and tested its function while accelerating the process of making and assembling the structural-thermal model (STM). In the fourth year, from February 2009 to January 2010, the team tested the environment of STM and made the structure of FM (flight model) that was to be actually launched. In the fifth year, from February to November 2010, the team focused on the assembly of FM and the preparation of the environmental test and the launching process.
Through its research, the team led by Professor Dai Gil Lee changed the related materials and structure and successfully reduced the structural weight of the satellite by about 14.8kg while certifying the thermal safety of the structure on the orbit. Such achievements led to the reduction of the launching cost by about $148,000 to $296,000. Also, by using the sandwich panel made of composite materials as the load path, it was possible to secure the structural strength and robustness of the satellite.
As the structural development of Science Technology Satellite No. 3 became successful, it was possible to expect various positive ripple effects. First, since Science Technology Satellite No. 3 is equipped with an infrared camera and a small-sized imaging spectroscope that could be used for the observation of the space and the earth, it will be possible for the satellite to collect infrared and spectral images of space and the earth from 600km above the ground for two years. The infrared images of space can be utilized for various astronomical research that focuses on the identification of the physical properties contained by the high-temperature gas and the origin of the galaxy as well as the spatial distribution of stars in the early stages of space. The infrared and the spectral images of the earth provide necessary information about such research topics as forest fire, floods, water pollution, ecological maps and estimated crop conditions, as well as various national disasters, making it possible to reduce social and economic costs.
By applying the domestically-developed technologies related to composite materials to the satellite field, it is possible to save the technological costs paid for the use of foreign technologies. Also, by using lightweight composite materials, it is possible to reduce the structural weight of the satellite and save the launching cost of the satellite, which is calculated at 10,000 to 20,000 dollars per kilogram.
By systematically analyzing the demands of the satellite and continuously developing small-sized high-tech satellites, it is possible to develop new satellite technologies and activate research related to space science. Also, through such a process, it is possible to improve the core satellite technologies developed in Korea and utilize the technologies in such basic research fields as astronomy and earth science. Furthermore, the manufacturing and the applied technologies obtained through the process of developing satellites based on the application of composite materials can be utilized in various fields of space science, making it possible to advance other related technologies and reduce the time for the development of products. In particular, high added values could be created, if latest technologies such as the manufacturing technology for the heat-controlling structure made of composite materials are transferred to the aerospace industry. Since there are not enough people with expertise and experience in the field of satellite heat-control in Korea, the successful execution of the research task is quite important as it will lead to the training of more experienced experts in the field.
All the technologies that are related to the structure made of composite materials and the heat-pipe are considered to be quite important for the development of the satellite structure/the heat-controlling system according to the National Technology Roadmap (NTRM). In other words, the research achievements of the team led by Professor Dai Gil Lee are quite significant, as they have increased the technological level of the satellite structural system in Korea up to that of any other advanced nation in the field of aerospace.
Prof. Lee, Dai Gil
2013 Annual Report