Hab Consumable Masses in Mars Direct
This is the page for estimating the masses of consumables in Mars Direct as part of the Tsiolkovsky Compendium Project. On page 92 of his book The Case For Mars, Zubrin estimates them to be as follows:
- Consumables: 7.0 Tonnes consisting of (TCFM page 92):
- Oxygen: 160 kg total (1 kg/man*day at 80% reuse)
- Dry Food: 1600 kg total (.5 kg/man*day at 0% reuse)
- Whole Food: 3200 kg total (1 kg/man*day at 0% reuse)
- Potable Water: 0 kg total [?] (4 kg/man*day at 80% reuse)
- Wash Water: 2080 kg total (26 kg/man*day at 90% reuse)
On the space shuttle, Oxygen is used at a rate of .8 kg per person*day . Zubrin's 1 kg per day seems reasonable, especially considering that astronauts will be using this Oxygen at a high rate. This reference suggests that under a high metabolic load, such as that will probably exist for astronauts doing work on Mars, .96 kg per day is more reasonable. 1 kg per day is a good starting point considering margin necessities and losses.
Based on technologies pioneered on the ISS, 90-95% closure for oxygen seems reasonable . Assuming the lower number, that is 0.1 kg per day of oxygen. Over 600 says with 4 people, that is 240 kg. With 95% closure, that is 120 kg of oxygen. An intermediate value falls at 180 kg, right near Zubrin's 160 kg.
Total Mass for 600 day Mission
Based on the above, a figure of 180 kg of Oxygen is a reasonable estimate.