Chinese space telescope: New rival to James Webb unveiled
Chinese scientists have detailed their work on the Chinese Space Station Telescope (CSST), a modern observatory designed to rival the James Webb Telescope, built by NASA, ESA, and CSA. They note that it will be capable of remaining in orbit for decades.
China is developing a new state-of-the-art space telescope to compete with the world's leading observatories. Named the China Space Station Telescope (CSST), it will match the capabilities of the advanced James Webb Telescope (JWST) and can also be serviced and upgraded directly in orbit.
Xuntian, the new Chinese space telescope
Its name is Xuntian, which translates from Mandarin as "surveying the heavens", aptly describing its mission. Scientists have published new details regarding the project in the scientific article repository arXiv under the title: "Future Cosmology: New Physics and Opportunity from the China Space Station Telescope (CSST)."
CSST will join the ranks of modern telescopes, such as Euclid, launched by the European Space Agency in July 2023; the Nancy Grace Roman Space Telescope, which is in the final stages of launch preparation; and the Vera C. Rubin Observatory, a large ground-based installation that will soon begin operations. These massive observatories have a broad range of scientific goals, including conducting research in the universe to solve various cosmological mysteries.
The Chinese space telescope is set to be launched no earlier than 2026, and its main mirror will have a diameter of approximately 2 metres. Although this is slightly less than the width of the Hubble Telescope's mirror, the advanced optics of the CSST will allow it to achieve a field of view at least 300 times greater than Hubble's.
Uncovering the mysteries of the cosmos
Thanks to its capabilities, the CSST will conduct many significant tests and measurements. One of the primary goals will be to measure an effect known as weak gravitational lensing. Light from distant galaxies is slightly distorted by small curvatures in space created by other galaxies. By mapping hundreds of thousands of galaxies, researchers hope to create detailed maps of matter distribution in the universe. These maps may help scientists understand the mysteries of dark matter, which, although constituting most of the matter in the universe, does not interact with light and thus cannot be directly observed.
On a larger scale, the CSST will engage in studying the statistics of voids and galaxy clusters. Voids are massive empty spaces between galaxies, while clusters are groups of galaxies. The properties of these structures – their size and distance from each other – depend on the nature of dark energy, a mysterious substance that seems to accelerate the universe's expansion.
Additionally, the CSST will search for supernovae and measure baryon acoustic oscillations. Supernovae serve as constant reference points to distant galaxies, while baryon oscillations are remnants from the time when the universe was still plasma, billions of years ago. Both phenomena are crucial for understanding cosmic evolution.
The CSST will complement other top-class instruments, enabling access to different areas of the universe and at various distances. There is hope that all four world-class telescopes will coordinate their efforts.
The telescope will be close to the Tiangong space station
However, the CSST has another significant advantage. It is no coincidence that its name includes the word "station": once launched, it will share an orbit with the Chinese space station Tiangong. Although they won't always fly alongside each other, their orbits will regularly bring them closer together. This facilitates the Chinese space agency's ability to service the telescope, replace instrument modules, and even perform upgrades – which will be impossible for other space telescopes. While other devices will have a limited operational time, the CSST can provide valuable cosmological data for many more decades.
