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A fragile space.

A collision can create fragments that cause further collisions - a chain reaction known as Kessler syndrome. Fengyun-1C shows what one destructive event can leave behind.

ESA: Kessler syndrome ↗ · NASA report ↗

Data & methods

A Crowded Space

GCAT / Jonathan McDowell and CelesTrak SATCAT · snapshot 30 September 2026.

The source table contains 0 objects. The cumulative launch chart uses 0 Earth-payload records. The shared scene contains 0 payload records with valid plotting data; the current selection contains 0. Debris and rocket bodies are outside that payload selection. Fengyun uses a separate debris family.

One JCAT record, one point. The globe uses representative altitude and inclination, with illustrative orientation and phase. Orbital heights use a compressed radial scale.

Orbital Lives follows the original selection: ongoing Earth-payload O/AO phases, blank phase end, no CelesTrak decay, valid plotting values. Its 0 records include inactive satellites and potentially stale statuses.

Atlas angle encodes launch date across 320 degrees; radius encodes logarithmic representative height. The histogram includes all plotted historical payload records by launch year, including later re-entries. Starlink is separated from other payloads by default.

Historical presence uses launch and documented removal dates. Incomplete phase histories and unresolved endings limit the reconstruction. The opening sky uses the original Highlands observer, a 78° field of view and deterministic Kepler orbits. The sky and trail phase use real-time modelled orbital speed: one second on screen equals one orbital-model second. Trails build gradually and retain up to the latest five minutes. These are modelled historical positions; brightness and current tracking are not measured.

Collisions can create fragments that cause further collisions, a self-sustaining process known as Kessler syndrome. The Fengyun test illustrates fragmentation and long-lived debris; these snapshots do not show a collision cascade.

Fengyun-1C: the parent marker is schematic. Transitions connect snapshots, not physical fragment trajectories. The one-day view is reconstructed from later January elements. The 12 October 2026 view uses elements at most seven days old. Fragment identities persist between views; absent records fade out. These samples have different coverage and do not form a survival curve.

Cumulative launches include unique Earth-payload records with a known launch date through 30 September 2026, without requiring valid orbital plotting values. They include later re-entries. The future band compares selected dated deployment plans with a two-year delay, subtracting launches already recorded in each cohort. Linear interpolation between milestones is assumed. Other future launches and replacement needs are excluded, except for explicit OneWeb renewal orders. This is a partial timing scenario, not a global forecast or probability interval. Starlink uses the original name-or-programme match. Mass uses the original four launch-mass bands; zero or missing values use a cross.

Filed constellation plans
Jonathan McDowell · 13 Oct 2026
One million (paper) satellites
Falle et al. · ITU filings, 2017–2022
Space Environment Report
ESA · end-2025 observations

Asset licences and credits

Records in this view by purpose
Purpose	Records
Communications	0
Earth observation	0
Navigation	0
Science	0
Technology	0
Other	0

Scroll: satellite → one day after → present