China is building its own Hubble-like space telescope with a 2.5-billion pixel camera

Commonly known as the Chinese Space Station Telescope (CSST), Xuntian (Heavenly Cruiser) is readying to become China’s first major telescope in space. Unlike previous space telescopes such as Hubble, this orbiting observatory, due for launch in 2024, will be orbiting alongside the Chinese large modular space station, able to dock with the outpost when needed.

One of the most-important characteristics of a telescope is its diameter — which limits how much light it can take in at a single time. The main mirror in Xuntian will have a diameter around two meters (six-and-a-half feet) across, roughly the size of the mirror at the heart of the Hubble Space Telescope. However, the CSST will be able to see 300 times as much sky at one time as its older compatriot.

“The telescope will be set up in an optical module that can fly independently in orbit… [W]e will make it fly approximately in common orbit with the future space station. This will help us refuel the telescope and carry out in-orbit upgrade[s] for it,” Zhou Jianping, a leader in China’s human spaceflight program, told China Central Television.

This pairing would represent a significant advantage in servicing over the Hubble telescope, which required several Shuttle missions to repair and upgrade.

Looking high, looking low, looking everywhere I go…

With its impressive field of view, the CSST (sporting a camera with 2.5 billion pixels) will be capable of studying 40 percent of the sky over 10 years. Examining the Cosmos in visible and ultraviolet light, Xuntian seeks to understand the nature of dark energy and dark matter, two of the greatest mysteries in astrophysics today.

“It can simultaneously perform the photometric imaging and spectroscopic slitless surveys, and will probe weak and strong gravitational lensing, galaxy clustering, individual galaxies and galaxy clusters, active galactic nucleus (AGNs), and so on,” researchers from the National Astronomical Observatories (NAOC) describe in a 2019 article.

Closer to home, the Chinese Space Station Telescope will study regions of space just beyond the most distant planet in our solar system, searching for signs of trans-Neptunian objects (TNOs). This new eye in the sky will also protect our own planet, keeping an eye out for near-Earth asteroids.

“If you plan for one year, plant rice. If you plan for ten years, plant trees. If you plan for 100 years, educate mankind.” Chinese Proverb

China is also building four research stations to study data collected by CSST, and the CNSA has started training crews to assemble this mighty observatory. Assembly of Xuntian will take place in space, consisting of four crewed and seven robotic missions to the orbiting telescope, scheduled for this year and next.

Credit: CNSA