Vacuum

A vacuum is an area that is virtually empty of matter, usually found in space. Most life forms cannot survive in a vacuum for very long.

The few exceptions

 * Time Lords, for limited periods (DW: Four to Doomsday)
 * Daleks (DW: The Parting of the Ways)
 * Cybermen (DW: The Moonbase)
 * Toby Zed while possessed by the Beast (DW: The Impossible Planet)
 * Star Whale (DW: The Beast Below)
 * Ahab, for an unknown reason (K9TV: The Bounty Hunter)

People killed by exposure to vacuum

 * Katarina (DW: The Daleks' Master Plan)
 * Kirksen (DW: The Daleks' Master Plan)
 * Varan (DW: The Mutants)
 * Scooti Manista (DW: The Impossible Planet)
 * Chief Steward (DW: Voyage of the Damned)