ALASKA — China wants to build a number of telescopes in deep space to look for planets that are habitable and circle other stars.
Four light-collecting telescopes and a beam combiner will be sent to Sun-Earth Lagrange point 2 as part of the Miyin project. To directly image and describe exoplanets near stars up to 65 light-years distant, the spacecraft will fly in formation and employ interferometric methods to give high angular resolution mid-infrared images.
The major goal would be to find Earth-like planets that may support life around nearby Sun-like stars in the Milky Way.
Although the project is still in the planning stages, the current schedule calls for on-orbit technology demonstrations in 2024 and interferometry tests aboard the Tiangong space station the following year.
A prototype of the array would then be launched in 2027, followed by the construction of the five-spacecraft system at L2 in 2030. In a second mission phase beyond 2030, four more satellites might be added to the array.
The center beam combiner and telescopes are expected to work at a distance of between 40 and 300 meters, according to an earlier journal study. For systems up to 20 parsecs distant, the array will have a spatial resolution of 0.01 arcseconds.
The idea was introduced at a celebration of China’s national space day in Hefei, Anhui province. Since 2016, the celebration has taken place every year to commemorate the Dongfanghong-1, the nation’s first satellite, which was launched on April 24, 1970.
According to Sarah Casewell, research fellow, and lecturer at the School of Physics and Astronomy at the University of Leicester, if authorized and implemented, the project would have significant scientific significance.
“The proposed spatial resolution of 0.01 arcseconds is comparable or better than NASA’s proposed Habitable Worlds Observatory, which is likely to have a six-meter-diameter mirror and a coronagraph to image exoplanets in the habitable zones of 100 stars within 25 parsecs,” said Casewell.
Multiple space telescope systems have previously been proposed, such as NASA’s Terrestrial Planet Finder and ESA’s Darwin concepts. NASA is exploring an $11 billion project called the Habitable Worlds Observatory, which would launch in the 2040s and operate in the ultraviolet, visible, and near-infrared spectrums.
This multi-spacecraft approach, which will complement JWST and Habitable Worlds, which have a comparable spatial resolution but may include a coronagraph or star shadow for high contrast imaging, is what I believe to be unique among currently scheduled exoplanet missions.
A variety of celestial bodies in our solar system, as well as protoplanetary disks, active galactic nuclei, and other objectives, would all be observed by the Miyin expedition.
The endeavor reflects the expanding Chinese interest in extraterrestrial research. The China Aerospace Science and Technology Corporation (CASC) is in charge of the mission’s design. If the concept is authorized after on-orbit testing, the formation flying and interferometry portions of the mission will present a number of technological obstacles.
Meanwhile, the Chinese Academy of Sciences is reviewing two proposals for exoplanet-hunting satellite observatory missions as part of its Strategic Priority Program on satellite Science. The missions are the Closeby Habitable Exoplanet Survey (CHES) and Earth 2.0 (ET).
CHES would employ astrometry, the same approach used by ESA’s Gaia star-mapping satellite observatory, while ET would monitor 1.2 million dwarf stars using the transit method.
