Reconciling Martian and Terran environmental needs

[gjc8]

Originally Posted by vicky_molokh

Correct, but the little dragons were assembled differently, and modifying them isn't exactly feasible (at the moment, anyway).

Well, that was specifically addressing the fact that the dragons have no problem with CO2 levels well-below Mars-normal. Since they're something different, it wouldn't necessarily be so. But since THS biotech is clearly up to producing parahumans than can deal with both Earth-normal and Mars-normal levels of CO2, there's no reason to be surprised that the dragons are also capable of handling both Earth-normal and Mars-normal CO2 levels.

Originally Posted by vicky_molokh

Thanks, this is exactly the sort of thing I was wondering about. Is there a way to measure the level of this fire hazard based on oxygen content? (I'm assuming you mean specifically the %, since partial pressure is no higher than normal.)

Originally Posted by MEDICAL AND PHYSIOLOGICAL CONSIDERATIONS FOR A HIGH-ALTITUDE MMA SITE

As a general rule, fire hazard decreases as the partial pressure of oxygen decreases, because of the reduced amount of oxygen available for combustion, and increases as the partial pressure of nitrogen decreases, because of decreased nitrogen quenching. Whether or not a particular atmosphere provides increased or decreased fire hazard depends on which of these effects dominate and on the particular material considered for combustion. The NFPA (1993) defines an oxygen enriched atmosphere to have increased fire hazard, in the sense that it will support increased burning rates of materials, if the percentage concentration of oxygen is greater than 23.45/(TPatmos)^0.5...A commonly used atmosphere in the Space Shuttle and Space Station is 527 Torr (10.2 psi, 0.69 atmos.) barometric pressure, 30 % oxygen, which is used to promote nitrogen washout prior to entering the low pressure (4 psi) spacesuit atmosphere for extravehicular activity. Burning rates for a number of common materials have been measured (NASA, 1992) at the NASA White Sands Test Facility in New Mexico in this 0.69 atmos, 30% oxygen atmosphere. It is reassuring that NASA considers the risk associated with this oxygen enriched atmosphere, which has a significantly higher partial pressure of oxygen than the MMA oxygen enriched atmosphere, to be acceptable, even for a permanently manned spacecraft such as the Space Station....
The discussion in the previous paragraph was concerned principally with the fire hazard of solid materials. Common sense requires that flammable gases and liquids must not be used in an oxygen enriched atmosphere....Volatile liquids require careful handling even without oxygen enrichment. Olsen (1995b) has found that volatile liquids ignite more easily on top of Mauna Kea and their vapors spread more readily than at sea-level. This is due in part to the fact that the flash point of volatile liquids decreases as barometric pressure is reduced. The flash points of typical volatile liquids such as benzene and ethanol are about 8°C lower at 5000 m altitude than at sea-level (NFPB, Fig 3-5D, 1992).

Emphasis added.
MEDICAL AND PHYSIOLOGICAL CONSIDERATIONS FOR A HIGH-ALTITUDE MMA SITE

.6 bar and 30% oxygen is right on the border of the definition of an oxygen enriched atmosphere provided by that formula.