In April 12th, the project of science and technology cooperation between China and India for the development of TMT segment system was accepted by the expert group. The acceptance meeting was organized by the China Science and technology exchange center, with the authorization of international cooperation division of the Ministry of science and technology.
Both China and India are the partners of the Thirty Meter Telescope (TMT) International Observatory (TIO). Both sides will undertake the research and development of 86 TMT segment mirrors. In 2013, the summary of “the 6th meeting of Joint Commission on scientific and technological cooperation between the People's Republic of China and the Republic of India” elaborated the will of the two countries to strengthen cooperation in the field of astronomy and astrophysics.
It specifically designated the National Astronomical Observatory (NAOC) of the Chinese Academy of Sciences and the India astrophysics Institute as the executing unit, focusing on the International cooperation in this field such as the development of the TMT major mirror.
The Nanjing Institute of Astronomical Optics and Technology (NIAOT) of the NAOC developed a new method to mass-product the off-axis aspheric surface for the segment mirror of the giant optical telescope, which can significantly shorten the development cycle and reduce the cost. In the cooperation of this project, NIAOT has obtained a number of new technologies with independent intellectual property rights.
It explored the technology to manufacture about 90 hexagonal aspheric segment mirror with angular diameter of 1.44m, and mastered the key technology of the complex shape machining of the TMT segment mirror. The Indian side, cooperated with the US side, developed a set of sub mirror support system through TMT inspection after many experiments, which was shipped to China in June 2017. After that, a set of segment mirror unit integration tests were completed in Nanjing, which verified the complex segment support system and the precise assembling process of the off-axis optical mirror using assembly workstation. The segment mirror support system, which is provided by the Indian side and the TMT headquarters in the United States through years of engineering practice, careful simulation and test optimization.
The completed assembly test is in NIAOT is the necessary technical interface for the cooperation of China and India to complete the TMT project.
The major mirror system of TMT will be composed of 492 hexagonal segment mirrors supported by the active optical technology. In order to achieve optical surface precision, its complex manufacture process and huge working amount will be completed by the United States, Japan, China and India, respectively. The cooperation between China and Indian under the framework of TMT project is a good example of division of labor in international astronomical and scientific engineering construction.
aluminum surrogate segment mirror and sub mirror support system assembled together
