A ship's life support system is vital for organic crew in order for them to be in the ship for a prolonged period without a voidsuit. Life support systems contain several subsystems that circulate the ship with breathable air, keeps the temperature of the ship to an adequate level, and maintains the pressure of the ship. Life support systems also manage functions such as waste disposal and water recycling.
Life support is vital to the crew, and a damaged support system can spell doom. Even breach to the hull of a ship can be dangerous, as it can cause part of that ship to depressurize, making it dangerous for crew to be in.