CSS (WENTIAN)
Country: China, People's Republic of
Live Position
Ground Track · Last 90 Minutes
Upcoming Passes · Over Your Location
About This Satellite
Wentian is a laboratory module of China's Tiangong space station, launched in July 2022. Its scientific facilities support studies of plants, cells, and biological processes in space. Experiment cabinets provide controlled conditions and measurements; the laboratory is not simply a cabin where organisms are left to grow without monitoring.
Plant experiments can control more than light
The scientific payload designer describes a cultivation system with adjustable lighting, temperature, and gas composition, including carbon dioxide. Cameras monitor growth and send observations to Earth. Controlling those conditions helps researchers interpret a biological response without treating every difference from a ground-grown sample as an effect of microgravity alone.
A centrifuge supplies a comparison inside the space laboratory
Wentian includes a variable-gravity facility using centrifugal motion for comparative experiments. The artificial loading applies to samples in that apparatus, not to the entire module. Automated observations are complemented by crew tasks such as replacing samples, handling them in a glovebox, and preserving material for later analysis on Earth.
Mission reference: CAS: Wentian scientific payload designer on life-science facilities. Editorial review: .
A catalog number does not mean independent flight after assembly
CNSA records Wentian's move from Tianhe's axial docking port to a radial port on September 30, 2022. This made the station L-shaped before the arrival of Mengtian. Wentian's catalog identity preserves its launch history, but an attached module travels with the station. Do not interpret a separate catalog entry or an old free-flight TLE as evidence that it is currently circling Earth independently.
Reference: CNSA: Wentian relocation and Tiangong assembly.
The module also provides crew and backup infrastructure
The launch account describes an airlock for crew spacewalks, three sleeping areas, and backup functions for station control and life support. These systems make Wentian more than a collection of experiment racks. The crew airlock should also be distinguished from Mengtian's cargo-transfer airlock: both bridge a pressurized interior and space, but their intended users and handling arrangements differ.
Reference: CAS: station designers on Wentian crew facilities, airlock and backup functions.
Reading this orbital snapshot
Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 387 km at perigee to 390 km at apogee, a difference of 3 km. The orbital period is about 92.3 minutes. Eccentricity 0.00023 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.00 times apogee speed. These are mean-element estimates, not instantaneous measurements. Distance per orbit uses an ellipse approximation.
Saved build snapshot. If a valid TLE is retrieved, this explanation and the orbit panel update together. Otherwise this dated snapshot is retained.
Ground track is not sensor coverage
An inclination of 41.47 degrees implies approximate geocentric ground-track limits of 41.5 degrees north and south. This is a prograde orbit, moving in the same general direction as Earth rotation. The plotted line marks the point beneath the object. It does not represent camera coverage, radio reception, or a guaranteed visible pass.
Accuracy and missing information
The introductory record describes the build snapshot. The orbital snapshot explanation and orbit panel share any successfully retrieved TLE; check the displayed epoch. Reentered objects retain historical data only. Mission history is not rewritten by TLE updates. TLE/SGP4 positions are predictions and can change after maneuvers or updated observations. The 14-day stale-data cutoff is a display safeguard, not an accuracy guarantee. Local passes are geometric predictions, not a visibility forecast. No verified operator or mission status means unknown, not active. Do not use this catalog for collision avoidance or operational flight decisions.
Catalog sources: CelesTrak SATCAT: NORAD 53239 · GCAT: S53239 (source update 2026 Sep 4 2345:57). Supplementary metadata: SatNOGS DB, retrieved 2026-09-05T12:57:25.375Z. Page assembled 2026-09-15. GCAT phase codes describe trajectory phases, not mission health.
Learn more: TLE data · Perigee and apogee · Ground tracks · JOT (Jewawud Live Orbital Map)