Communications blackout

For the Mercury, Gemini, and Apollo spacecraft, such communications blackouts lasted for several minutes.

[5] Communications blackouts for re-entry are not solely confined to entry into Earth's atmosphere.

[1] Until the creation of the Tracking and Data Relay Satellite System (TDRSS), the Space Shuttle endured a 30-minute blackout.

The TDRSS allowed the Shuttle to communicate by relay with a Tracking and Data Relay Satellite during re-entry, through a "hole" in the ionized air envelope at the tail end of the craft, created by the Shuttle's shape.

[1] Radio blackouts on Earth caused by solar flares are measured by the National Oceanic and Atmospheric Administration on a scale from 1 (minor) to 5 (extreme).