It is proposed to provide an initial manned Lunar base with an updated life support system (LSS) exploited at the Mir orbital station and ISS in context of such criteria as minimal mass expenditure and maximal closure. Preliminary estimation of such LSS reliability was made, as well feasibility and suitability to improve regeneration subsystems in order to reduce expensive resupply delivery and save crew time for assembly of the lunar infrastructure. LSS reliability is defines as a probability of crew loss in consequence of failure of an essential regeneration subsystem. It was shown that with a 5-fold increase of the mean error-free running time of all subsystems the probability of crew loss may be equal to 0.005–0.01 at the condition that each subsystem has 2 cold redundancy units if its functional time is two years, 3 units if its functional times is 10 years and 4 units if its functional time is 15 years. Calculations made with the use of 3 cost-reliability models demonstrated that the proposed updating is justified, as the cost of subsystems will increase in 4.6 times on the average.