The TianQin project: Current progress on science and technology

Jian-Wei Mei, Yan-Zheng Bai, Jia-Hui Bao, Enrico Barausse, Lin Cai, Enrico Canuto, Bin Cao, Wei-Ming Chen, Yu Chen, Yan-Wei Ding, Hui-Zong Duan, Huimin Fan, Wen-Fan Feng, Hong-Lin Fu, Qing Gao, Tian-Quan Gao, Yun-Gui Gong, Xing-Yu Gou, Chao-Zheng Gu, De-Feng Gu, Zi-Qi He, Martin Hendry, Wei Hong, Xin-Chun Hu, Yi-Ming Hu, Yue-Xin Hu, Shun-Jia Huang, Xiang-Qing Huang, Qing-Hua Jiang, Yuan-Ze Jiang, Yun Jiang, Zhen Jiang, Hong-Ming Jin, Valeriya Korol, Hong-Yin Li, Ming Li, Ming Li, Peng-Cheng Li, Rong-Wang Li, Yu-Qiang Li, Zhu Li, Zhu-Lian Li, Zhu-Xi Li, Yu-Rong Liang, Zheng-Cheng Liang, Fang-Jie Liao, Qi Liu, Shuai Liu, Yan-Chong Liu, Li Liu, Pei-Bo Liu, Xu-Hui Liu, Yuan Liu, Xiong-Fei Lu, Yang Lu, Ze-Huang Lu, Yan Luo, Zhi-Cai Luo, Vadim Milyukov, Min Ming, Xiao-Yu Pi, Cheng-Gang Qin, Shao-Bo Qu, Alberto Sesana, Cheng-Gang Shao, Chang-Fu Shi, Wei Su, Ding-Yin Tan, Yu-Jie Tan, Zhuang-Bin Tan, Liang-Cheng Tu, Bin Wang, Cheng-Rui Wang, Feng-Bin Wang, Guan-Fang Wang, Hai-Tian Wang, Jian Wang, Li-Jiao Wang, Pan-Pan Wang, Xu-Dong Wang, Yan Wang, Yi-Fan Wang, Ran Wei, Shu-Chao Wu, Chun-Yu Xiao, Xiao-Shi Xu, Chao Xue, Fang-Chao Yang, Liang Yang, Ming-Lin Yang, Shan-Qing Yang, Bo-Bing Ye, Hsien-Chi Yeh, Sheng-Hua Yu, Dong-Sheng Zhai, Cai-Shi Zhang, Hai-Tao Zhang, Jian-dong Zhang, Jie Zhang, Li-Hua Zhang, Xin Zhang, Xue-Feng Zhang, Hao Zhou, Ming-Yue Zhou, Ze-Bing Zhou, Dong-Dong Zhu, Tie-Guang Zi, Jun Luo

Abstract: TianQin is a planned space-based gravitational wave (GW) observatory consisting of three Earth-orbiting satellites with an orbital radius of about 10⁵km⁠. The satellites will form an equilateral triangle constellation the plane of which is nearly perpendicular to the ecliptic plane. TianQin aims to detect GWs between 10⁻⁴Hz and 1Hz that can be generated by a wide variety of important astrophysical and cosmological sources, including the inspiral of Galactic ultra-compact binaries, the inspiral of stellar-mass black hole binaries, extreme mass ratio inspirals, the merger of massive black hole binaries, and possibly the energetic processes in the very early universe and exotic sources such as cosmic strings. In order to start science operations around 2035, a roadmap called the 0123 plan is being used to bring the key technologies of TianQin to maturity, supported by the construction of a series of research facilities on the ground. Two major projects of the 0123 plan are being carried out. In this process, the team has created a new-generation 17cm single-body hollow corner-cube retro-reflector which was launched with the QueQiao satellite on 21 May 2018; a new laser-ranging station equipped with a 1.2m telescope has been constructed and the station has successfully ranged to all five retro-reflectors on the Moon; and the TianQin-1 experimental satellite was launched on 20 December 2019—the first-round result shows that the satellite has exceeded all of its mission requirements.