Talk:Experimental setup

Experimental setup assumptions for greenhouse heating

The assumptions for the experiment are not best related to what is needed for an economic greenhouse on Mars. Plants do not need 20 C constantly to survive and produce a crop. If they go down to 2 C many plants just slow down. In my household garden I did not worry about plants dying unless there was a frost. Since some plants can grow at 12000 feet altitude, they should be able to get by with only 63% of atmospheric pressure. People can operate at a little less than one half an atmosphere on the side of Mount Everest if they have oxygen enrichment, but no plants or animals live at 0.15psi pressure as found on Mars. Heating from sunlight is exactly what would be needed for an economical greenhouse on Mars. There should be flat windows level with the ground for a soil sheltered Martian greenhouse. The windows should be triple or quadruple paned glass for good insulation. About 8 feet wide and 400 foot long windows of multiple 8 inch square panes in a steel frame could hold the pressure and allow considerable heating by real greenhouse effect (as opposed to the atmospheric heating of planets that is only similar to the heating in greenhouses). Numerous windows with the corresponding greenhouses beneath them could be separated by enough space for long flat mirrors to direct a double dose of sunlight into one greenhouse row without shading the next if that is found to be necessary. I suspect that instead there will be a need for radiators to provide sufficient cooling.

At 0.63 atmospheres pressure, there would be 39 tons of upward force on each 8 foot square section of greenhouse roof. That could be reasonably anchored to the dirt with structural steel. Plants are very adaptable and could be bred to get along with less intense than usual Earth level sunlight, as indeed many plants on Earth now are adapted to growing in shady areas. Growing food would be more expensive on Mars than on Earth, at least at first, but if there is an economic product on Mars that can pay for the greenhouses, they are not impossible.--Farred 01:56, 30 November 2009 (UTC)

My intention is to reduce the experimental setup effort by defining a constant temperature, only for the experiment. Yes, you are right, the real greenhouse temperature will not be constant due to the fact that plants live in cycles as much as almost every living thing is. Plants can, however, not transform light energy to chemical energy at low temperatures very efficiently. We have to find an optimum, because light energy is a valuable resource on Mars. So it won't help us to slow down the metabolism of the plants. -- Rfc 19:43, 1 December 2009 (UTC)