On Monday, March 28, 2016 at 3:26:22 PM UTC+13, JF Mezei wrote:
On 2016-03-27 19:56, William Mook wrote:

A crewmember of typical size requires approximately 5 kg or 11 lb(total) of food, water, and oxygen per day to perform the standard activities on a space mission, and outputs a similar amount in the form of waste solids, waste liquids, and carbon dioxide.

When you consider heat produced and force exerted on objects during
phsyical activity, does this involve any transformation of mass into
energy ? Or are these simple chemical reactions that produce heat/force
but total mass is conserved although some electrocs are re-arranged as
atoms form new molecules etc ?

Well, the 5 kg includes air water and food. The 0.62 kg per day of food, is the dehydrated portion of the foods. Very similar to what was carried on board by the Apollo and Gemini astronauts during their weeks long flights. These portions contain energy.

http://spacefeelings.com/images/pict...ace-food-7.jpg
http://i.kinja-img.com/gawker-media/...90lqkt0jpg.jpg

The amount is what was consumed on those flights on a daily basis. The basal metabolic rate is the primary driver of food consumption. This is a product of Lindeman's 10% law. While there may be momentary exertions that are 50% or 100% greater than baseline, it is not sustained for very long periods, so even someone who does daily exercise or daily exertions, overall averages are not much different than for these. These values are also at the upper quintile. 80% of the people eat less than this. So, in a sizeable crew, providing for this amount provides for more than is likely to be needed under all circumstances.


Type 1
Stored oxygen, water & food --- waste discharge Mercurcy, Gemini, Apollo, Soyuz, Vostock,

Type 2
Recycled oxygen, stored water & food -- CO2 recycled, other waste discharged, ISS

Type 3
Recycled oxygen & water, stored dehydrated food -- CO2 & H2O recycled, other waste reduced to C.

Type 4
All recycled foods -- CO2, H2O and biowastes recycled, Stanford Torus

4a: Farm system - farm recycling, Stanford Torus
4b: Cell cultures - cell culture recycling
4c: Direct synthesis - chemical recycling