Editing Life Support

All space vessels and facilities require extensive life support systems to support their crews. These systems are basically the same on all Federation ships and space stations. Life support systems maintain a single environment, suitable for most Federation races, although individual species, like the Benzites, may require supplemental devices, such as respirators to help them breathe. Life support systems have to meet the highest safety standards. On Galaxy-Class starships they are designed with multiple backups and redundant safety checks that protect the crew, even in the event of multiple systems failure. For instance, the atmospheric support system to the Main Bridge features seven independent safety interlocks. 

Except for gravity, which is created by generators throughout the ship, this safety net includes mutually supportive parallel trunk lines and a reserve utility distribution network for limited supplies of basics such as air, power and water. Life support equipment centers are on Decks 6,9 and 13 in the primary hull, and Decks 11,21,24, and 34 in the engineering hull. 

In the rare event of a system wide failure, there will still be sufficient atmosphere to maintain the crew for several hours. The exact length of time will depend on the number of personnel on board, and how many panic.

Atmosphere:

Reflecting the overall ergonomic design, an oxygen-nitrogen atmosphere is maintained for Class-M life forms as a shipwide norm. Per standard 102.19 set by STARFLEET regulatory Agency, this amounts to air at 26oC, and 45% relative humidity at a pressure maintained at 101 kilopascals, amounting to 78% nitrogen, 21% oxygen, and 1% trace gases. 

On the Galaxy class, some 10% of the habitable living space can be adjusted to classes H,K, or L environment norms without hardware modifications. Another 2% are equipped for swapout to classes N and N2. However, the entire ship can be altered for natives of classes H-K-L planets with the replacement of atmospheric processor modules in a major Starbase refit. 

Processors are located throughout the ship at a rate of about two redundant units per very 50 cubic meters of habitable ship's volume. The units combine carbon-dioxide removal with oxygen replenishment, mostly accomplished via natural photosynthetic ioprocessors. Normal maintenance calls for each side of the parallel system to take the load every 96-hour cycle, which allows for maintenance on the other, although individual units can be switched between the two for greater flexibility and redundancy. 

The third backup atmosphere net can provide up to 50% of the system capacity for up to 24 hours. In addition, if the main and reserve atmospheric systems fail, contingency atmospheric modules, available at most corridor junctions, can cover evacuation, repair, or shelter-seeking time of approximately 30 minutes.

Artificial Gravity:

Aside from the ease of mobility for work and play it affords, and the pleasing 'natural' feel, artificial gravity has long been known to be practically indispensable for off-world living, due to its necessity for cellular growth and health. 

For the Galaxy-class Starship, hundreds of simple synthetic gravity generators provide the Class-M norm, tied in to the inertial dampers to counteract acceleration effects in an effect much like the tractor beam, each generator creates a gravity field by using a controlled stream of gravitons generated by a superconducting stator rotating at speeds over 125,540 rpm, powered by energy tapped from the electro-plasma system (EPS). The stator, built, built of thoronium arkenide, is in turn suspended within pressurized chrylon gas in the center of a hollow sealed chamber of anicium titanide 454, measuring only 50 cm in diameter and 25 cm tall. This device provides a graviton field of only a few picoseconds, so the decay time demands that generators be located every 30 meters or so. Thus, the ship at large includes two networks of 400 generators each in the primary hull, and two more networks of 200 each in the engineering hull. The generators are tied together by small waveguide conduits to allow 'field bleed' in cases of extreme maneuvering and inertial movement.

Each stator is built in suspended state, and is maintained with only a synchronizing EPS energy pulse every hour or so. In the case of EPS loss, the stator will provide an attraction field for up to 240 minutes, with a dip down to only about 0.8g predicted. Sinesopidal ribs on the inner surface of each generator's sealed cylinder absorb motions with an amplitude up to 6 cm per second. 

The crew are protected from the effects of acceleration by the inertial damper field, which enables the ship to accelerate to high speeds without pulverizing ship's personnel.

Waste Management:

Since no starships can carry the required amounts of food and water for extended missions, recycling and waste reclamation is a must. 

Aboard the Galaxy-Class, complexes on Decks 6,13 and 24 include treatment and recycling units for liquid waste, all of which is recycled into fresh water, food replication, or general matter replication. 

Solid waste is handled in processors on Decks 9,13 and 34. These scan for composition, and route items to the most practical means required. 

Some 82% of all solid waste can be recycled mechanically, but any material that cannot be directly recycled this way or chemically - including about 5% of all waste classed as hazardous - is set aside for general matter replication. Due to the energy-intensive nature of full matter dematerialization, which is in effect a one-way transporter, most recycling is accomplished by the older and more common methods

Reliability:

Modern life support systems can cope with a number of situations that would have been fatal on earlier starships and space stations. Most notably, hull breaches are automatically contained by forcefields. 

Under normal circumstances, life support is extremely reliable. STARFLEET calculates that, barring a serious accident, life support failure should only occur once every five hundred years.

Backup Systems:

Despite the redundancy built into all Starship systems, designers must allow for emergency backup systems in case of system loss or damage. 

For the Galaxy class, the philosophy is twofold - a 30 minute shipwide lighting and power backup system to cover repair time if needed, and 52 designated emergency shelters, such as the forward observation lounge at Deck 10, Section 1. 

The backup system includes 425 of the corridor junction modules cited earlier which, in addition to atmospherics, include emergency lighting and batteries. The shelters, powered by a series of dedicated and protected power trunks, are designed to sustain up to 65 crewmembers for up to 36 hours. They also include 24 hours' worth of air, water, food and power supplies independent of even the backup, as well as two emergency pressure garments. 

Even in the event of an emergency, it is highly unlikely that life support will fail throughout the ship. In the event of a partial systems failure, the Commanding Officer may opt to evacuate or, on a Galaxy-class Starship, the Commanding Officer may initiate a saucer section separation, with the entire crew taking refuge in the unaffected section.