China aims to build a series of telescopes in deep space to search for habitable planets orbiting other stars. The Miyin project involves sending four light-gathering telescopes and a beam combiner to the Sun-Earth Lagrange point 2. Flying in formation, the spacecraft will use interferometric techniques to provide high angular resolution mid-infrared observations to directly image and characterize exoplanets around stars. up to 65 light years.

The primary goal will be to detect potentially habitable terrestrial planets orbiting Sun-like stars in our Milky Way neighbor. The project is still in development, but current plans call for a demonstration of the technology in orbit in 2024, followed by interferometry experiments a year later at the Tiangong Space Station. Then, a prototype array will be launched around 2027, and a system of five spacecraft will be built on L2 by 2030. Four more spacecraft could be added to the lineup in the second phase of the mission after 2030.

A previously published journal article suggests that the telescopes and central beam combiner will operate between 40 and 300 meters. The array will have a spatial resolution of 0.01 arcseconds for systems up to 20 parsecs distance. The concept was unveiled at an event celebrating China’s National Space Day in Hefei, Anhui Province. The event has been held annually since 2016 and was dedicated to the anniversary of the launch of the country’s first satellite, Dongfanghong-1, on April 24, 1970.

According to Sarah Casewell, a researcher and lecturer in the School of Physics and Astronomy at the University of Leicester, the project will be of great scientific value if approved and implemented.

“The proposed 0.01 arcsecond spatial resolution is comparable to or better than NASA’s proposed Resident Earths Observatory, which will likely have a six-metre diameter mirror and coronagraph to view exoplanets in regions with 100 stars within 25 parsecs.” casewell He told SpaceNews.

Systems consisting of multiple space telescopes have been proposed before, including NASA’s Terrestrial Planet Finder concept and the Darwin ESA concept. NASA is considering an $11 billion project called the Habitable Earths Observatory, which will begin in the 2040s and will operate in the ultraviolet, visible, and near-infrared bands.

“I think this multi-spacecraft concept will complement the JWST and Habitable Worlds that are unique to currently planned exoplanet missions and will have similar spatial resolution but likely a coronagraph or star shadow for high-contrast imaging.”

The Miyin mission will be used to observe some celestial bodies in our solar system, as well as other targets such as protoplanetary disks and active galactic nuclei. The project is a reflection of China’s growing interest in studying exoplanets. The mission project is managed by the China Aerospace Science and Technology Corporation (CASC). If the project is approved after orbital testing, it will face numerous technical challenges related to group flight and interferometric aspects of the mission.

Meanwhile, the Chinese Academy of Sciences is considering a pair of proposals for space observatories to search for exoplanets under the Strategic Priority Program for Space Sciences. These are the Closeby Habitable Exoplanet Survey (CHES) and Earth 2.0 (ET) missions. CHES will use astrometry, the same technique used by ESA’s Gaia space telescope, to compile star maps, while ET will use the transit method to observe 1.2 million dwarf stars.