Re-entry

Reentry is the term used to refer to the transition from the vacuum of space to the atmosphere of a planet or other celestial body. This often occurs at high speed to take advantage of aerobraking (using wind resistance to slow the vehicle) and is a critical time for the spacecraft. Any errors in this portion of the flight profile are difficult to recover from and will probably have large impact upon the mission. Death and/or mission failures have occurred in this flight regime.

See also: Space Shuttle Columbia disaster