Object
Atmospheric Density Jackets
The Doctor and Ian pull on these protective jackets, dubbed Atmospheric Density Jackets (ADJ) by the Doctor, before stepping from the powerless TARDIS into the planet's thin, hostile atmosphere. They shield wearers from sub-normal air pressure for about an hour. Once that limit passes, both men clutch their chests in distress, discard the failing gear, and expose themselves to the lethal environment amid the shock of the vanished TARDIS.
4 appearances
Purpose
Shield wearers from thin planetary atmosphere for limited duration
Significance
Their one-hour failure strands the Doctor and Ian without protection on the hostile planet surface, amplifying vulnerability after the TARDIS disappears and shifting the story from exploration to desperate survival.
Appearances in the Narrative
When this object appears and how it's used