Skill: Engineering
Difficulty: 11
Uses Module: No
Can be done Remotely: No
Energy: None
Can be done more than once per Round: Yes

Applies to times when the ship isn't in a mission. If there are more people aboard the ship than there are life support capabilities (each module supports 4 crew) then all characters suffer 1D6 damage per person that exceeds the supportable number.

If a character has no life support they must make an Athletics check vs 11 or suffer 1D6 damage that bypasses armour (but not alien abilities). A character is supported if-

1. they are on a ship with at least one functioning Life Support module
2. they are in a boarding missile
3. they are holding an EVA that is functioning

Life Support may handle any number of people during the mission (which is, after all, a very short duration). As long as there is at least one functioning LS module there is no limit to the number of (people/bots/aliens) on the ship. If there isn't even one LS module, everybody (without an EVA) takes “unsupported” damage at the end of the round.

Unsupported damage can be healed with a medkit.

If there are more crew (and bots) aboard during warp in, then all suffer from “Overstressed Life Support Damage” for the duration of the mission. You check for overstressed life support for the journey to and from base after resolving any upgrades. (p48)

“Overstressed” damage cannot be healed with a medkit.

Full discussion can be found at: http://www.boardgamegeek.com/geekforum.php3?action=viewthread&threadid=34253