Since the successful launch of Taiji-1 on August 31, 2019, it has obtained a series of valuable on-orbit test data, marking the first step for China in space gravitational wave detection. To detect the low-frequency gravitational waves generated by the combination of large-mass black holes, the Taiji Program in Space will launch three satellites in the final step to form an equilateral triangular formation constellation with a side length of 3 million kilometers, so as to greatly promote the development of instruments and observational astronomy.
Recently, researchers from the Space Pangu Lab of the Hangzhou Institute for Advanced Study (HIAS), UCAS, Nanyang Technological University, Institute of Theoretical Physics, Chinese Academy of Sciences (CAS), the University of Queensland, and the Australian National University published a review article inNature Astronomy, in which they reviewed the development and prospect of satellite constellation astronomy by combining the launch and in-orbit testing of the Taiji-1 satellite.Nature Astronomy is a sub-journal of natural sciences founded in 2017 by the famous British journalNature. In 2019, the SCI impact factor of the sub-journal reached 11.518. It becomes an international authoritative academic journal in the field of astronomy.
The review article was written by Igor Levchenko, a professor from Nanyang Technological University, Xu Shuyan, the person in charge of the Hall Micro Propulsion System for Taiji-1 and a professor from Nanyang Technological University, Wu Yueliang, a member of CAS, Dean of the School of Fundamental Physics and Mathematical Sciences of HIAS and Chief Scientist of the Chinese Space-borne Gravitational Wave Detection Program "Taiji", and Kateryna Bazaka, a professor from the Australian National University, among others.
Constellation of Earth Orbit Satellites.
The article points out that the use of distributed instrumentation systems to collect astronomical and astrophysical data is not a new idea. There are already several global networks composed of ground-based radio astronomy instruments and optical telescope systems. Until recent years, establishing and maintaining a huge network of distributed astronomical instruments in space is still beyond our engineering technological and financial support capabilities. But we need to see that the development of artificial intelligence and new technologies bring hope to this plan.
The article emphasizes that large-scale formation constellations of satellite constellations orbiting the Earth, such as active-communication 3D satellites and commercial small satellites, China's Taiji or Europe's LISA for instance, may bring new technical capabilities because such constellation networks have large coverage characteristics and are more sensitive and flexible. The biggest advances in satellite formation constellations are making the exploration of distant celestial bodies more affordable, and reducing the risk of failure.
Statistical Chart of Commercial 3D Satellite Constellations from 2017 to 2019.
The article concludes with a discussion of potential threats to ground-based observation astronomy from satellite formation constellations. The large-scale constellations currently under construction can be used to support navigation, geodetic survey, telephone and information services, broadband internet, weather and climate monitoring, remote sensing, etc. But tens of thousands of these satellites will illuminate the night sky soon, threatening the operating environment of ground-based astronomy.
While we are facing an explosive growth of satellite constellations, astronomers, satellite engineers and policymakers, as well as other possible stakeholders, should work together to find a mutually acceptable path for this potentially valuable technological development—protecting the environment we already have while strengthening our space exploration capabilities.
The article was published on June 29, 2020. Article link:
Nat Astron (2020)
https://doi.org/10.1038/s41550-020-1141-0
Source: School of Fundamental Physics and Mathematical Sciences,HIAS
Text by: Tang Xiangqin, Shang Zhiping, and Zhang Xinyue
Editor | Jiang Xuchen
