Life Support Systems

I was just thinking about life support systems on-board the ships and looking at the standard LS rules, I realized that there must be some pretty amazing tech implied behind the shipboard life support systems.  So much so that I think it is unrealisitic and really needs to be revisitied.<br /><br />Looking at the rules, it says that the entire life support machinery to support 1-2 beings weighs in at a measely 3 kg.  That 1.5kg (about 3 pounds) per person.  And that is enough to supply those 2 beings with food and water for 200 days.  And scaling up gets even better.  You can support 1,000 beings on only 600 kg of equipment and supplies, that's only 0.6 kg per person, less than half as much.<br /><br />Personally, I find that pretty crazy.  I imagine a more realistic system has two ratings, one for the maximum number of people that the system can support at any one time and another for how many days supply of food can be stocked up.  The first value would determine the amount of machinery and infrastructure is needed on the ship (for processing systems, duct work, pipes, food preparation, etc.)  This would be the fixed cost expended when the ship was built.<br /><br />The second determines how long your crew can go without replenishment of supplies.  You have to specify a maximum value at construction time that determines the hull volume devoted to storage but beyond that this tells you the resupply cost for the system.  And of course you can store some additional life support supplies in your cargo hold if you need to.<br /><br />I see something like this (these values are completely random off the top of my head):<br />Maximum capacity:  10 cubic meters per person (so if you want to be able to support a crew of 20, you need to devote 200 cubic meters to life support systems)<br />Supply volume:  each being-day of life support supplies takes up .05 cubic meters or 20 days per cubic meter.  Thus if you wanted your ship that supported a crew of 20 to have 200 days of supplies, you'd need 4000 supply units and to devote an additional 200 cubic meters of hull space to consumables storage.<br />Supply cost: 5 cr per day of supplies.  Your 4000 supply units would cost you 20,000 cr for every 200 days of supplies.<br /><br />I can also see there being different grades of supplies as well, with higher quality lifesupport taking up more space and costing more.<br /><br />Anyway, just some ideas that came to me recently.  Feel free to comment.  I'll be looking at more exact values over the next little while.<br />