Total number of cataloged objects currently being tracked in Earth orbit, including active satellites, defunct satellites, rocket bodies, and debris fragments.
0
Updated in real-time from TLE
TLE (Two-Line Element set) is a standardized data format used to describe the orbit of an Earth-orbiting object. Published by the US Space Command, TLEs enable prediction of an object's position at any given time.
data
Active Conjunctions (10d)?
A conjunction occurs when two objects in orbit pass close to each other (within 1km). These events are monitored continuously to assess collision risk and determine if avoidance maneuvers are needed.
0
Predicted close approaches < 1km
Major Debris Sources?
Largest debris-generating events in orbit. These breakups — from collisions, explosions, or anti-satellite tests — account for thousands of tracked fragments.
0
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Orbital Congestion?
How crowded is each orbital regime? Calculated from the spatial density of tracked objects — total object count divided by shell volume — using real-time Space-Track catalog data.
LEO
MEO
GEO
HEO
MODERATE
LEO 800–1000 km band: highest debris density
⚡ Collision Probability?
Estimates the probability that two specific objects will collide within a given time window. Free version includes 50 sample objects; PRO unlocks the full Space-Track catalog (45,000+ objects).
Object 1 (NORAD ID or name)
Object 2 (NORAD ID or name)
Time Window
Min. miss distance—
Relative velocity—
TCA—
—
—
How is this calculated?
Uses a simplified Kessler spatial density model: collision probability = 1 − exp(−V_rel × σ / V_shell × N_orbits), where V_rel is relative velocity from orbital elements, σ is combined cross-section, and V_shell is the shared orbital shell volume. For production use, PRO version applies SGP4 orbit propagation with Alfano's method using full covariance matrices.
Orbit Distribution
LEO (200–2,000 km)0
MEO (2,000–35,786 km)0
GEO (~35,786 km)0
HEO / Other0
Data Sources?
Orbital data from US Space Command's public catalog (Space-Track.org). Conjunction alerts from Space-Track CDM (Conjunction Data Messages) provided via CSpOC.
Space-Track.org GP catalog Space-Track CDM (via CSpOC)