China is developing a new space telescope called the China Space Station Telescope (CSST). This exciting project aims to match the capabilities of the renowned James Webb Space Telescope (JWST) while being repairable and upgradable from space.
The CSST is set to join a new wave of powerful telescopes, including the Euclid space telescope launched by the European Space Agency, NASA’s Nancy Grace Roman Space Telescope, and the Vera C. Rubin Observatory. Each of these telescopes is designed to explore the universe and tackle some big questions in cosmology.
In Mandarin, CSST is called Xuntian, which means “surveying the sky.” This name highlights its mission to observe and map distant galaxies. Scientists recently shared more about the telescope’s goals in a paper uploaded to arXiv.
Expected to launch no earlier than 2026, the CSST will feature a mirror 6.6 feet (2 meters) wide. Although it’s slightly smaller than the Hubble Space Telescope’s mirror, its advanced technology will give it a field of view that is 300 times greater than Hubble’s. The telescope will detect light across the near-ultraviolet to near-infrared spectrum.
The CSST will focus on several key areas of research. One major goal is to measure weak gravitational lensing. As light from distant galaxies travels to Earth, it gets bent by the gravitational fields of intervening galaxies. By analyzing the small distortions in their shapes, astronomers can create detailed maps that reveal how matter is distributed throughout the universe. This could shed light on dark matter, which makes up most of the universe but is invisible to us.
In addition to mapping galaxies, the CSST will study vast empty spaces called voids and dense clusters of galaxies. Understanding the size and distance of these regions is crucial for unraveling the mysteries of dark energy, a force that seems to be speeding up the expansion of the universe.
Moreover, the CSST will search for supernovae and measure baryon acoustic oscillations. Supernovae serve as markers for measuring distances to galaxies, while baryon acoustic oscillations are echoes from the universe’s early days as a hot plasma. Both are essential for piecing together the universe’s evolution.
By complementing other world-class telescopes, the CSST will provide a broader view of the universe. The goal is for all four telescopes to work together, sharing data and insights.
Notably, the CSST’s name includes “station” for a reason. It will share an orbit with the Chinese Tiangong space station. While they won’t always be side by side, their orbits will align periodically. This proximity allows the Chinese space agency to service the telescope easily, swap out instruments, and perform upgrades—something other space telescopes cannot do. This means the CSST could offer valuable data for many years to come.
