Re-entry prediction is one of the hardest problems in orbital mechanics. The time window narrows as the event approaches — but even hours before re-entry, predictions can be off by thousands of kilometres because of the speed involved.
Re-entry prediction is one of the hardest problems in orbital mechanics. The time window narrows as the event approaches — but even hours before re-entry, predictions can be off by thousands of kilometres because of the speed involved.
A decaying object loses altitude gradually, then rapidly in the final hours. The rate depends on atmospheric density — which itself depends on solar activity, geomagnetic conditions, and the object's attitude.
A common misconception: the prediction should get precise days in advance. In reality, the uncertainty window only narrows meaningfully in the final few hours.
Orbital Radar's re-entry tracker displays the predicted re-entry window — and it updates as new TLE data arrives.
Scientists should be able to predict exactly where debris will land
At 7.5 km/s, even a 10-minute uncertainty covers 4,500 km. Precise landing prediction is physically impossible until the final minutes.
Big objects always burn up completely
10–40% of a large satellite's mass can survive re-entry, depending on materials. Titanium tanks and carbon fibre structures often reach the ground.
The prediction window narrows over time but never reaches pinpoint accuracy until the very end. This isn't a failure of technology — it's a consequence of atmospheric variability and orbital speeds.