Second station

Tiangong — China's space station

Tiangong is the second permanently crewed station in orbit and the smaller of the two. Its 41.5° inclination gives it a noticeably different ground track from the ISS.

The core module Tianhe launched on 29 April 2021. Two laboratory modules, Wentian and Mengtian, were added in 2022, giving the station its characteristic T-shape. Total mass is roughly 100 tonnes — about a quarter of the ISS — with three pressurised modules and a robotic arm.

Why its passes look different

The 41.5° inclination is the key number. The station's ground track never goes further north or south than 41.5° latitude. That means:

• Overhead passes are common between roughly 30° and 45° north or south — southern Europe, the Mediterranean, Japan, central China, the southern United States, southern Australia.
• Low passes only north of 45° — the UK, the Netherlands, Germany, Poland, Scandinavia. It stays near the southern horizon and never climbs high.
• Never visible from latitudes above about 46° or below about -46°, except in rare cases of a very low, grazing pass.

From the Netherlands or Belgium, Tiangong is therefore a harder target than the ISS: it appears lower, is dimmer, and spends less of each pass above the horizon. It is still visible to the naked eye on a good evening pass, at roughly magnitude 0 to +1.

Tiangong versus the ISS

Track it live

Switch the tracker between stations with the ISS and TIANGONG buttons at the top of the front page. The globe, altitude and velocity figures follow the selected object.