LESSON 02 OF 6

Breakup + survivability

Intermediate ~9 min Slide deck Free

As an object enters the atmosphere at 7+ km/s, aerodynamic heating converts kinetic energy into heat at a rate that destroys most materials within seconds. What survives tells us about composition and structure.

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What this lesson covers

What Survives and What Burns

Material properties — melting point, density, thermal conductivity — determine survivability.

The Debris Footprint

Surviving fragments spread across a ground footprint spanning hundreds to thousands of kilometres.

Key facts

💡NASA estimates roughly 20–40% of an object's mass typically survives to ground level for objects not designed for controlled entry.

💡No person has ever been confirmed killed by re-entering space debris. One verified case of debris striking a person: Lottie Williams, 1997, minor injury.

Re-entry risk is dominated by uncertainty — but most debris burns up.

The combination of mostly-ocean corridors and mostly-ablated mass means uncontrolled re-entries, while newsworthy, carry extremely low individual risk.

All lessons in Re-entry Deep Dive

01Why predictions shift~9 min 02Breakup + survivability~9 min 03What corridor means~10 min 04Controlled vs uncontrolled~9 min 05Myths and headlines~9 min 06Public guidance~9 min

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