Lithobraking

Lithobraking is a term used by spacecraft engineers to refer to a spacecraft reducing its velocity by impacting the surface of a planet or moon. Originally coined as whimsical euphemism for a "crash landing", it is now also used when the collision is deliberate. The word was coined by analogy with "aerobraking", slowing a spacecraft by intersecting the atmosphere, with "lithos" (Ancient Greek: λίθος [líthos], "rock") substituted to indicate the spacecraft is intersecting the planet's solid lithosphere rather than merely its gaseous atmosphere.

According to Jonathan McDowell, "Lithobraking reduces the apoapsis height to zero instantly, but with the unfortunate side effect that the spacecraft does not survive. Originally a whimsical euphemism, but increasingly a standard term."

The term Lithobraking has been popularised by the video game Kerbal Space Program as a euphemism for spacecraft crashes.