SZ-21 MODULE
SZ-21 MODULE is associated with China's Shenzhou crewed-spaceflight program and Tiangong operations. Shenzhou spacecraft carry crews to and from low Earth orbit and form the transportation backbone of China's human-spaceflight architecture.
Object identity
- NORAD ID
- 66515
- COSPAR ID
- 2025-246C
- Operator
- Not listed
- Country
- Not listed
- Launch date
- Not listed
Immediate discovery
Why this satellite matters
Crewed rendezvous combines phasing-orbit mathematics with human-safety constraints: trajectory design must preserve abort options and avoid collision geometry throughout approach.
Understanding the mission
Science and engineering ideas
Crewed rendezvous combines phasing-orbit mathematics with human-safety constraints: trajectory design must preserve abort options and avoid collision geometry throughout approach.
Mission
Mission and purpose
Objects in this category may be crewed stations, modules, cargo vehicles, or other spacecraft directly connected with human activity in orbit. The exact role depends on the individual object.
- Crewed rendezvous combines phasing-orbit mathematics with human-safety constraints: trajectory design must preserve abort options and avoid collision geometry throughout approach.
Design
Engineering
Crewed rendezvous combines phasing-orbit mathematics with human-safety constraints: trajectory design must preserve abort options and avoid collision geometry throughout approach.
Real orbital values
The mathematics
The current two-line element set reports approximately 15.8552 revolutions per day. Dividing 1,440 minutes by that value gives an estimated orbital period of 90.8 minutes.
Period
90.8 min
Representative speed
27,782 km/h
Representative altitude
322 km
Inclination
41.47°
Launch record
Launch and deployment
The orbital catalog lists the launch designator as 2025-246C. A fully sourced launch story, launch vehicle, deployment sequence, historical weather, and documented delays have not yet been added to this page.
Orbit
LEO orbit explained
Low Earth orbit is the region closest to Earth used by most crewed spacecraft, many science missions, Earth-observation satellites, and large constellations. Objects move quickly and commonly complete an orbit in roughly 90 to 130 minutes.
LEO can provide detailed Earth views, lower communications delay, and easier access than higher orbits, but it covers less area per spacecraft and is more affected by atmospheric drag.
Live TransitSatellite experience
See SZ-21 MODULE moving now
Open the live tracker to view its current calculated position, trajectory, orbital information, visibility tools, and Save and Share controls.
Learning
Questions to explore
- Why do low-orbiting stations circle Earth many times per day?
- How do crews receive power, supplies, and communications in orbit?
Evidence
Sources and data notes
Current identity and orbital elements come from CelesTrak’s public GP data. Calculated orbit values are derived from the current TLE and may change after catalog updates. Mission-history claims are added separately and require authoritative sources.
Catalog updated
Sep 17, 2026, 8:52 AM UTC
Story review
1970-01-01T00:00:00.000Z