LIFE SUPPORT AND ENVIRONMENTAL CONTROL

	Of all major shipÕs systems, life support and environmental control 
are among the most critical. Every key system element is designed with 
multiple redundancy to provide for maximum crew safety, even in the 
unlikely event of multiple system failure. Under normal operating conditions, 
the mean time between failure for the environmental systems should exceed 
five hundred operating years. Even under such a total failure, emergency 
backups should insure crew survival in most situations.

	Major life support equipment facilities are located in the Primary Hull 
on Decks 6, 9, and 13. In the Engineering Hull, major life support equipment is 
located on Decks 11, 21, 24, and 34. The primary life support systems 
comprise two parallel systems, each serving as a backup to the other. 
Synthetic gravity generators are located throughout the habitable volume of 
the spacecraft.

	Each major life support facility includes a tie-in to the reserve utilities 
distribution networks. These tie-ins include a limited supply of critical 
consumables, including breathable air, power supply, and water. The 
reserve utilities distribution network is designed to provide minimal life 
support and power in the event of complete disruption of both primary 
environmental support systems.

	Other emergency provisions include distributed reserve life support 
systems, emergency support shelter areas, and contingency support 
modules intended to provide shipwide breathable atmosphere for up to thirty 
minutes in a major systemwide failure.  Æ