Design

Let’s discover together all the technical aspects of our experiment

A lot to discover!

The aim of our experiment is the study of air pollutants of anthropogenic and natural origin through an economic and easily reproducible device that can quickly intervene in the study of restricted areas. 

The necessity of being and feel ourselves protagonists of the changes and the recent and dramatic events, led us to think about a system that can improve, maybe in a small part, the study and the thought of intervention on the environmental situation.

The first step of our experiment consists in collecting, at different altitudes, the atmospheric air, trapping, with a system of filters, the solid particles and different gaseous substances including pollutants, such as brominated compounds. 

After the flight of the balloon, we will be able to analyze the samples and, thanks to the values of temperature and pressure, in addition to those of altitude, we will characterize not only the composition of the air at each altitude, but we will be able to build dispersion curves and models for each analyte. Another objective of our experiment is the knowledge of the percentages of ozone and UV radiation in the quotas of interest. This would allow us to predict possible reactions in situ and to think of solutions for intervention or prevention. 


To date many of the compounds called Freons have already reached high atmospheric stages, the heaviest, the brominated compounds, have a slower rise, in anticipation of this, our experiment also aims to theorize models to know the rise and predict harmful impacts on the ozone ecosystem.

The experiment consists in a dynamic sampling system with subsequent analysis of the collected samples. 

An in situ analysis would entail higher costs with the risk of placing equipment unsuitable for the atmospheric environment under investigation

The system is composed of a physical/chemical collection part and a real time sampling part (through sensors). The collection system is divided into a system of filters that are opened according to altitude and a bag that accumulates air (canister) during the floating phase. 

The air is directed inside the device by a suction pump. It is positioned after the filters so that the compounds are forcibly adsorbed into the filters. The outlet of the pump discharges the air to the outside or, thanks to a system of valves, drains the air to the canister to fill it. 

When the canister is filled, an “empty” filter is selected upstream of the pneumatic system so that the bag can be filled with unaltered air. 

The totality of the sensors is distributed as follows: 

-The thermal sensors are located in various areas inside and outside the box and monitor the temperature for scientific purposes and for the safety of the entire system. Temperature sensors affect an active thermal control system that allows the necessary temperature ranges to be maintained.

-The arrangement of sensors that are measuring technical and scientific data are divided between internal and external. The external ones are not significantly affected by the environmental conditions while the internal ones are arranged in a small box.

The internal sensor box is kept under pressure by a diaphragm pump that sucks air from the outside to the inside so as to maintain the pressure required for optimal data reading. 

The experiment will host three devices that will work independently and remotely: a revolver mechanism will contain the filters, a box will host the canister and another one will contain the sensors. Four pumps will be installed (two of them for redundancy) which will allow the air flow to pass through the filters and then fill the canister and the third and the fourth one (diaphragm pumps) will be dedicated to maintaining a continuous flow inside the box containing the sensors.

The environmental sensors will operate continuously throughout the flight (except during descent phase) and will measure concentrations of pollutants such as NOx, SOx, VOC, CO2. In addition sensors will monitor temperature, humidity and pressure inside the device. The filters will rotate according to the altitude reached during the experiment. In particular: the first filter will be used from 5 km to 15 km, the second from 15 km to 25 km, the third from 25 km up to the maximum altitude. Then the balloon will reach the floating phase and there will be used the fourth and fifth filters.


ESA-BEXUS