GreenHab Report – December 21st

Today began the transplantation of lettuce plants into the Greenhab!
We chose our heartiest crop as the test cultivar for GreenHab
conditions.  Temperatures have seemed to normalize but today was
completely cloud-covered and therefore hostile conditions may return
with the sun.  We are leveraging differences in soil and hydroponic
systems in order to compare which growing systems may have advantages
in an analog Martian habitat. Conveyor plant stages were setup for Red
Oak Lettuce today.  Eight developmental stages will be present by the
end of the mission. Six were carefully separated from the Rockwool in
order to minimize root damage and planted into equal volumes of wet
soil.  The hydroponic setup involved creating a hydroponic solution
suitable for the broad range of plant life stages present in the
conveyor experiment.  This involved starting with tap water and first
adding a nutrient solution to get the electrical conductivity (EC) to
an appropriate level.  This brought the EC to about 1.9 mS/cm.  The
next step was to lower the pH to a slightly basic value.  After
calibrating the sensor, the pH was reading 6.06 which was well within
the acceptable range.  If all goes well, Green Oak Lettuce and other
cultivars will be transplanted tomorrow.