Our second mission will orbit around acid rain and is divided into two fronts: gas measurements and remote sensing.
What is acid rain?
When the pH reaches lower values than 5,6, the rain gets the designation of acid rain. What really lowers the pH to these levels are nitric (HNO3), sulfuric (H2SO4) and sulfur (HSO3) acids. These are formed when there is contact between rainwater and SO2 gases (sulfur dioxide), SO3 (sulfur trioxide) and NOx (nitrogen oxides) by the following equations:
SO2 (g) + ½ O2 (g) → SO3 (g),
SO3 (g) + H2O (l) → H2SO4 (aq)
2NO2 (g) + H2O (l) → HNO2 (aq) + HNO3 (aq).
Because our station's top priority is to measure the propensity of the environment for the phenomenon of acid rain, all our measurement revolves around these gases. Just like in the first mission, the use of sensors is crucial.
The second part of our project relies on image analysis.
Radiation vs Plants
The plants need sunlight to live because it's with this energy supply they perform photosynthesis. The absorption of this energy is performed by photosynthetic pigments present on their surfaces, to which were tested the wavelengths that were best absorbed (Engelmann experiment). The radiation best absorbed by these pigments was in the spectrum of infrared, for exactly the same reason, it would be the wavelength least reflected by the plant. There are performed researches that indicate how the vegetation absorbs, reflects and emits radiation. In this way, and considering that there are reflected radiation spectrum to which the vegetation is healthy and others for which the vegetation is not healthy, is possible to us to differentiate diseased vegetation from healthy one.
This being the theoretical foundation, with the image taken by our cansat, we intend to relate the spectrum of radiation mentioned above and the vegetation zones. According to its intensity, we will relate to the plants health which will be compared to the quality of the atmosphere (previously collected by the said sensors).