1) the mass to range ratio of life support modules does not make any sense
basic life support
mass 5
range 6
ratio 1.2
environmental support
mass 5
range 9
ratio 1.8
stellar support
mass 7
range 12
ratio 1.7
deep space support
mass 9
range 15
ratio 1.6666
support field generator
mass 10
range 18
ratio 1.8
stasis field generator
mass 11
range 25
ratio 2.27
looking at the ratio's basic life support (T1) is the worst of the lot followed by deep space support (T4) then steller support (T3)
stasis field generator (T6) is the best of the lot with environmental support (T2) coming in second place third is support field generator (T5) because even though it has the same mass/range ratio it has a manufacturing cost of 86 compared to environmental's cost of 10 (x2 because environmental is half the size) and on top of that the support field generator has a maintenence upkeep.
atm the only reason to research life support after the first tech is to get the last tech