1. Introduction

Taiji Programme in Space is proposed to detect GWs with frequencies covering the range of 0.1mHz to 1.0Hz with higher sensitivity around 0.01–1Hz than eLISA. The Taiji program proposes to use a triangle of three spacecrafts in orbit around the Sun. Laser beams are sent both ways between each pair of spacecrafts, and the differences in the phase changes between the transmitted and received laser beams at each spacecraft are measured. The preliminary design for the Taiji mission is based on 3-million-kilometer separations between the spacecrafts, and the expected launch date is about 2033. 

The purpose of Taiji programme is to study the most challenging issues concerning massive black holes, such as how the intermediate mass seed black holes were formed in the early universe, whether dark matter could form a black hole, how seed black hole grows into a large or extremely large black holes and what is the nature of gravity.

2. Progress and Results

Taiji-01 is the first experimental satellite of Taiji Programme. It marks the first under the Phase-II of the Strategic Priority Program on Space Science (SPPSS-II) sponsored by the Chinese Academy of Sciences (CAS). As professor Yueliang Wu, director of ICTP-AP, is the chief scientist of Taiji programme, ICTP-AP is responsible for the implement, scientific research and management works.

ICTP-AP was responsible for the overall planning and coordination of the Taiji-01 project. Moreover, ICTP-AP undertook the construction and development of the scientific operation system which was one of the six systems of Taiji-01 project. Moreover, ICTP-AP joined the research of the hall-effect micro thruster system.

On August 31st, 2019, Taiji-01 launched successfully from Jiuquan Satellite Launching Center in northwestern China. By the end of 2019, the in-orbit tests were successfully completed, the functions and performance indexes of the satellite met the general requirements, and the results exceed expectations.

The in-orbit tests showed that the accuracy of displacement measurement of the laser interferometer on Taiji-01 could reach a 100-picometer order of magnitude. The accuracy of the gravitational reference sensor on the satellite reached ten billionths of the magnitude of the earth's gravitational acceleration. The thrust resolution of the micro-thruster on the satellite reached submicron-Newton scale.Taiji-01 achieved China’s highest accuracy of spatial laser interferometry; successfully conducted China’s first on-orbit drag free control technology test; firstly and internationally on-orbit verification of micro-newton level radio frequency ion propulsion technology and dual mode hall-effect micro thruster technology.

3. Taiji Consortium

In May 2017, Taiji working group initiated and founded the ‘Consortium of Gravitational Wave Detection Taiji Program in Space’ on the International Symposium on Space Gravitational Wave Detection. The consortium is an academic consortium developed by the national scientific research institutions and institutions of higher learning involved in the detection of gravitational waves，which is based on the "Taiji Programme" working group of the CAS. 

As an academic consortium, it aims at leveraging the strengths of long-standing multi-disciplinary talents in and out of CAS, comprehensive platform of long accumulated high-end forward-looking technology and large scientific equipment as well as the characteristics of interdisciplinary and integration of science and education in an effort to congregate all researchers nationwide dedicated to study of theory and experiment of gravitational waves to conduct research on Space Gravitational Wave Detection.

The members of the consortium are all the scientists participating in the research of Taiji Programme, and they are the specific implementation and completion personnel of the scientific research tasks of Taiji Programme.

4. Link to Programme Site

https://taiji.ictp-ap.org