The escape shuttle copies the gasses inside the escape area.

[Erik]

See how the shuttle is filled with.. Plasma?

Steps to reproduce

• Create a room inside the escape shuttle area.
  
• Fill the room with plasma, or any other gas.
  
• Wait for the shuttle to dock.

[KikiMofo]

Well yeah the shuttle sort just replaces what is already there with it's self. I assume the gas isn't getting replaced or something.