HXMT (HUIYAN)
Hard X-ray Modulation Telescope, or Huiyan, is China's X-ray astronomy observatory launched in 2017. It studies black holes, neutron stars, gamma-ray bursts and other energetic phenomena by observing high-energy radiation that Earth's atmosphere largely blocks.
Object identity
- NORAD ID
- 42758
- COSPAR ID
- 2017-034A
- Operator
- Not listed
- Country
- Not listed
- Launch date
- Not listed
Immediate discovery
Why this satellite matters
X-ray astronomy relies heavily on counting statistics: instruments often detect individual high-energy photons, so probability distributions and signal-to-noise calculations are central to interpreting observations.
Understanding the mission
Science and engineering ideas
X-ray astronomy relies heavily on counting statistics: instruments often detect individual high-energy photons, so probability distributions and signal-to-noise calculations are central to interpreting observations.
Mission
Mission and purpose
The current public orbital catalog identifies this object, but verified mission-specific information may be limited. TransitSatellite will expand this page when authoritative information is available.
- X-ray astronomy relies heavily on counting statistics: instruments often detect individual high-energy photons, so probability distributions and signal-to-noise calculations are central to interpreting observations.
Design
Engineering
X-ray astronomy relies heavily on counting statistics: instruments often detect individual high-energy photons, so probability distributions and signal-to-noise calculations are central to interpreting observations.
Real orbital values
The mathematics
The current two-line element set reports approximately 15.1917 revolutions per day. Dividing 1,440 minutes by that value gives an estimated orbital period of 94.8 minutes.
Period
94.8 min
Representative speed
27,389 km/h
Representative altitude
515 km
Inclination
43.02°
Launch record
Launch and deployment
HXMT launched on 15 June 2017 aboard a Long March 4B from Jiuquan Satellite Launch Center.
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 HXMT (HUIYAN) 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
- What can an orbit tell us before the mission is fully identified?
- Why are stable catalog identifiers important?
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 20, 2026, 3:00 AM UTC
Story review
1970-01-01T00:00:00.000Z