Life support system
Life support system, life sustaining system, life system or environmental control system (ECS), was one of the most crucial systems aboard any spacecraft. 

Life support systems were in use as late as the late 20th century, when recyclic life support systems were planned for the Millennium Gate. () As spacecraft became more advanced, life support systems began including artificial gravity and inertial damper controls. When main and auxiliary powers failed aboard a starship, the system received power from batteries. In the most critical cases, a safeguard in the computer ordered the evacuation of the ship in question. (; ) Aboard some vessels, the imminent failure of the life support system constituted a blue alert situation. ()

Travis Mayweather and his father once experienced aboard a vessel when the power generator went offline, grav-plating and life support went down. ()

Life support systems and pressure domes could be used to make a class K planet more hospitable for Humans. () A key component in 23rd century life support systems was the mineral topaline. ()

Environmental engineering was a section aboard  starships such as the  where life support activities were controlled and monitored. This section was located in the primary hull. () Life support control was another section where the life support system was regulated. ()

In 2267, the  was left with life support systems operative at a low power level after an encounter with the planet killer. ()

In the distress call from a Romulan warbird in 2369 which the  received, the status of the Romulan ship was included. Their life support systems were failing. ()

The same year, the runabout  returned from a routine mission in the Gamma Quadrant to Deep Space 9 because their life support was failing and the oxygen levels had dropped dangerously low. ()

Major Kira Nerys and Doctor Julian Bashir responded to a priority one distress signal from the Kobliad transport Reyab whose life support and central power linkage was failing. ()

In 2370, a Cardassian escape pod which measured five meters in length was detected 50,000 kilometers inside Cardassian space by the USS Enterprise-D. Because the pod's life support system was failing, Captain Jean-Luc Picard asked if they could get within transporter range without crossing into Cardassian territory. According to Lieutenant Commander Data, they would need to boost the gain of the confinement beam by at least seven percent to do so. Still too far away, Geordi La Forge augmented the frequency spread, which resulted in the confinement beam being at 109 percent of normal and allowed a successful beaming of the pod passenger to safety. ()

Major Kira reported that life support was functioning normally after DS9 was hit by a gravimetric disruption caused by a nearby subspace rupture. ()

Before its atmospheric dome was added, Internment Camp 371 relied on life support systems in its walls to provide atmosphere. Enabran Tain used the old systems to send a message to Elim Garak in 2373. ()

After leaving Empok Nor, the Cardassians deactivated its life support systems. ()

In the Battle of Sector 001, the  lost its life support systems in the fight against the Borg. The Defiant crew, including Worf, was then beamed aboard the . ()

Hirogen body armor had internal life support and could protect a Hirogen hunter while seeking prey in most hostile environments, including the surface of a collapsed star. ()

A Federation  starship had tricyclic life support systems with an independent power source. ()

It appears that even when life support systems were disabled, it was still possible to maintain life aboard a starship for a limited period of time, using the oxygen that was already in the atmosphere. ()

In the alternate reality, the life support systems of  starships were controlled by a life support center located (in the) aft of the warp nacelles. If these systems were destroyed, there was no backup system in place. ()

See also 
 Air handling system
 Atmospheric stabilization
 Atmospheric system
 Environmental control
 Life support gear

External links 
 
 

de:Lebenserhaltungssystem
nl:Levenssysteem
pl:System podtrzymywania życia
Life support technology