On 11 Feb 2016 at 20:47, xxxxxx@comcast.net wrote:

> Having an alternate source of veggies and a back-up for oxygen
> regeneration, in my opinion, makes sense, but then again there is a
> limit to how much space would be needed.

Well, since the basic human "cycle" amounts to carbs + oxygen in, CO2
+ H20 out...

You'll wind up with more water than you started with. Which can be
broken down into hydrogen & oxygen.

Breaking down CO2 is harder, but possibly doable.

On the other hand you can use stuff like lithium hydroxide to absorb
the CO2, and then heat the cartridge in a vacuum to drive off the
CO2.

Or, given that you have refrigeration gear that can keep liquid
hydrogen around, you can just chill the air until the CO2 freezes out
and do something with the resulting dry ice.

Given the power available, water and air recycling are *easy*.

Hydroponics uses an awful lot of water and has trouble if you have to
cut off the gravity. Aeroponics is probably a better choice as it
uses both less warer and less space. and will work fine even in zero
g.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com