Life Support System
The purpose of a life support system is to provide a tolerable environment (breathing air, but also radiation shielding, heating/cooling, and a supply of consumables) for crew and passengers to live and work in relative comfort.
It should be noted that under classic boardgame BattleTech rules, Life Support is not the same thing as Environmental Sealing. While they often go hand in hand, life support systems do not require environmental sealing to be present. For example, IndustrialMechs always include life support system as part of their design, just like BattleMechs, but unlike the latter environmental sealing is not automatically included, and would have to be installed as an extra feature costing 10% of the design's total mass plus occupying one critical slot in every location. (Unlike a spacecraft, a standard IndustrialMech would operate within a breathable atmosphere where its life support system would not be required to provide breathing oxygen or protect against toxic gases or vacuum, but still shield the operator from heat or radiation.)
Large spacecraft such as DropShips generally have large oxygen reserves (more than 50 tons of oxygen are stated for a Union) and centralized air treatment systems, often with secondary systems such as local emergency oxygen supplies. They also typically budget around 500 liters of water per person per day, though the actual amount carried is much smaller, with filtration and recycling techniques in place to re-use stored water supplies over and over again.
A typical life support system on an aerospace fighter, where space and mass are limited, will not feature recycling capabilities by contrast, and provide oxygen and some drinking water for around 96 hours of operation from reserve tanks.
Under the Total Warfare standard boardgame BattleTech rules, DropShips and Small Craft can suffer a "Life Support" critical hit; the result is a non-cumulative -2 penalty to control rolls. Aerospace fighter hit tables do not feature critical hits against the life support system.
On 'Mechs, life support is automatically present and represented by two "Life Support" critical slots in the head section under classic boardgame rules, except under unusual circumstances (e.g. drone 'Mechs).
Standard BattleMech cockpits feature life support just like aerospace fighters. IndustrialMechs require the environmental sealing upgrade to achieve the same level of endurance.
A critical hit to the Life Support system on a 'Mech results in automatic pilot damage if certain heat level thresholds are passed, where the pilot would not have suffered damage with a functional system. Also, a critical hit to Life Support automatically nullifies the effects of Environmental Sealing and may thus kill the pilot in hazardous environments such as vacuum, toxic atmospheres or underwater.
Vehicles are treated very similarly to IndustrialMechs by the rules regarding life support and environmental sealing. However, their hit tables do not include critical hits against life support.
- TechManual, p. 69 - an IndustrialMech cockpit expressly includes two Life Support slots
- TechManual, p. 216
- Strategic Operations, pp. 256
- Strategic Operations, pp. 257
- Strategic Operations, pp. 256-257
- according to this official ruling by Joel "Welshman" Bacroft-Connors on the BattleTech forum:
'Mech Cockpit LifeSupport:
3 ton Standard cockpit equals ASF (96 hours, SO pg. 256)
Small Cockpit equals 1/2 ASF (48 hours)
Industrial and Primitive none. If equipped with Environmental Sealing it is equal to an ASF (96 hours)
Pg 195: Improved Life Support. Add the following sentence: "This quirk doubles the cockpit's standard life support time (see SO Pg. 256)"
Pg 198: Poor Life Support. Add the following sentence: "This quirk halves the cockpit's standard life support time (see SO Pg. 256)"