by China Manned Space AgencyCN
Map about 40% of the sky in sharp detail to measure dark energy and dark matter, and give China its own flagship space observatory that astronauts can service for decades.
Being readied for a 2027 Long March 5B launch, after earlier targets of 2023-24, 2025 and late 2026 slipped.
Updated 8 Jan 2026Checked 11 Oct0 updates this week
Hubble sees a tiny patch at a time. Xuntian's wide field and 2.5-gigapixel camera image a sky area hundreds of times larger per shot.
A survey camera, a spectrograph, a multichannel imager, a coronagraph to block starlight around planets, and a terahertz detector.
It flies in Tiangong's orbit but apart from it, avoiding station vibration. When it needs repair or upgrades it docks and astronauts work on it.
Faint distortions in the shapes of billions of galaxies reveal unseen mass along the line of sight, which tracks dark matter and dark energy.
| Spec | Xuntian (CSST) space telescope |
|---|---|
| Primary mirror | 2 mR (reported) |
| Survey camera | 2.5 gigapixelsR (reported) |
| Field of view vs Hubble | About 300 to 350 times largerR (reported) |
| Survey area | 17,500 sq deg (about 40% of sky)R (reported) |
| Mass | 15,500 kgR (reported) |
| Orbit | About 400 km, co-orbiting TiangongR (reported) |
| Instruments at launch | 5R (reported) |
| Planned mission | 10+ yearsR (reported) |
R reported by the company
China Manned Space Agency
Tiangong space station, crewed spaceflight
CMSA, founded 1993, oversees China's crewed spaceflight. Operates Tiangong, currently the only permanently crewed orbital station besides ISS and will be the sole operator after ISS retires in early 2031.
