Do we know the chemical makeup of water on Mars and the Moon? H2O itself doesn't do much good if it doesn't have the minerals and organic material plants need to grow.
There could be many toxins in the water for all we know, then they'd also need a filtration system.
Same goes for trying to use it as drinking water of course.
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Though, isn't growing crops part of the latter development of a colony? aside from a small science experiment of course. Thats why the Moon can be useful in the first steps, less costly to send resources. The Apollo sites also offer a lot of information on how man-made stuff decays on other planets. If they were to go near one, a lot of tests can be done.
Materials
One of the primary objectives in looking at the artifacts is to gauge the effect of the
lunar environment on different materials. Conditions on the lunar surface vary in temperature
from +250° F to -300° F and include exposure to ultraviolet and other forms of radiation, so
material surfaces after 40 years of exposure to this environment could be discolored, faded,
dulled, flaked, rumpled, pitted, mud-cracked, scratched, and/or covered with dust.
The LRV in particular should be considered a priority because it contains a wide variety of different
materials
There was also biological material left on the Moon, this is an other point of intrest.
Structural/mechanical
The temperature extremes may have caused some artifacts to exhibit
thermal effects, and the 500-plus day-night thermal cycles may have caused thermal fatigue
damage or deformation due to dissimilar metals being in contact with each other. In addition,
micrometeoroid impacts may have produced craters whose number, size, and appearance may
be useful in updating current models. Radially symmetric objects with several impacts may be
able to give some rough directional information as well.
Thermal
Most of the Apollo hardware received some form of thermal protection. This
included multilayer insulation (MLI), radiators/reflectors, and/or thermal paint. There is interest
is seeing how these different systems may have degraded.
Dust
Much has been documented on the characteristics of lunar dust and the deleterious
effect it has on equipment. There is also interest in dust transportation and d eposition from
human activities and natural processes. Flat surfaces (especially horizontal) and artifacts that
appear pristine in Apollo photographs would be optimum targets to look for dust deposition.
Blast Effects
Observations of how blast effects from nearby rocket engines vary as a function of
distance may be possible by looking at some affected artifacts.