Mars Astrobiology: Recent Status and Progress - Planetary Exploration and Science: Recent Results and Advances - page 222

technical and operational data by astronauts on how to accomplish these on Mars
(de Morais 2004 ).
So, my proposals have two objectives - first, to suggest this gravity simulation
in facilities on board the ISS, the only available place on Earth for a Mars gravity
simulation, and second, to suggest the construction of a simple greenhouse facility
on Mars for the growing of microbes and plants to produce oxygen and liquid water
within it, for a possible future terraforming of that planet (de Morais 2004 ).
Regarding those facilities on board the ISS, there are already data and results
available. These two suggestions are for the future, based on ground studies.
Possibly, this initial international manned Martian exploration will give place to a
future complex exploration and transformation of Martian characteristics for human
use, a Mars terraforming (de Morais 2004 ).
As mentioned above, for Mars terraforming, there is the possibility of future
introduction of some very resistant species of plants on Mars for the beginning of
a future long (several decades), gradual change of the Martian environment (e.g.,
Martian soil and atmospheric temperature profiles close to the ground), increasing
in some degrees the air and soil's temperatures for the transformation of sites
with permafrost into liquid water and the release of oxygen molecules into the
atmosphere, for future human use. To do this, we need first to understand how the
production of oxygen is on Earth, since it can be somewhat analogous to a future
terraforming of Mars (de Morais 2004 ).
Studies on the net production of oxygen by the phytoplankton on Earth's oceans
show that the oceans contribute 2/3 of the oxygen content in Earth's atmosphere
(Melillo et al. 1993 ), with a total oceanic primary production of 47.5 Pg C/year, with
the global seasonal variation production data, March-May, 10.9 Pg C/year; June-
August, 13.0 Pg C/year; September-November, 12.3 Pg C/year; and December-
February: 11.3 Pg C/year (Behrenfeld and Falkowski 1997 ).
Then, with the knowledge of which photosynthetic microbes and plants for
generating molecular free oxygen are resistant to present-day Mars, we will be
able to begin studies on how to gradually change Mars to a developed state (liquid
water and thicker oxygen atmosphere) capable of sustaining future human life. Good
initial candidates for very resistant organisms can be cyanobacteria, microscopic
algae, lichen, and cacti seeds (CAM-type plants, e.g., flowering plant species which
utilize crassulacean acid metabolism for the fixation of CO 2 )(deMorais 2004 ).
NASA-Ames Research Center has some studies on the two types of microscopic
algae, which grow in sand in hard conditions, Microcalens sp . and Escillatoria sp . ,
and their productivity are 100 mm CO 2 /m 2 /day. Equations (1) and (2) below (Benz
et al. 1997 ) give the influence of radiation on photosynthesis - the influence of
radiation on the photosynthetic partial rate assimilation process ( r Q ) is described by
a saturation function between the photocompensation point ( Q MIN ), which depends
on the ontogenetical (the genetic behavior of the organism during its life cycle) stage
of the cultivation, and the saturation point ( Q MAX ) of photosynthetic active radiation
( Q P ); the influence of temperature on photosynthesis partial rate ( r T ) depends on
ontogenesis and equals to 1 if the value of phototemperature is at the optimum
temperature ( T OPT )(deMorais 2004 ).