CanSat is a competition ran by the European Space Agency (ESA). It consists of a simulation of a real satellite, integrated within the volume and shape of a soda can. The challenge for the students is to fit all the major subsystems found in a satellite, such as power, sensors and a communication system, into this minimal volume. The CanSat is then launched by a rocket up to an altitude of approximately 1 km, or dropped from a platform, drone, or captive balloon. Then its mission begins. This involves carrying out a scientific experiment and/or a technology demonstration, achieving a safe landing, and analyzing the mandatory the data collected (pressure and temperature).
In this regard, team’s standout not only by the technical aspect, but by the scientific potential and innovation of their project. For CanACork, we highlighted the importance of the need for sustainable and cost-effective improvements to current satellites.
To achieve this, our secondary mission involved the use of a case made of cork and a thermoelectric generator (TEG). Why? The focus revolved around the CanSat’s thermal management. Usually, the heat flows originated by electronic components are discarded into space to prevent the system from overheating. So, our interest lied on the potential use of this residual heat as a way of generating electrical power to feed in the main power system. On one hand, cork acts as an excellent thermal insulator. This would allow the satellites internal heat to be kept in the system. Next, the TEG would convert that heat into potential energy. Hence, our scientific mission was to see how much energy we could produce.
Because of our ideas, CanACork participated in the final of CanSat Portugal 2023, among other 14 selected teams. The winner represents Portugal in the European Competition.
The satellite has 4 floors which all together amount to 115 mm. The lid has a diameter of 66 mm and our cylindrical case, made of cork, has a thickness of 2 mm. CanACork features a cylindrical case made of cork, aiming to simultaneously meet the resistance, aesthetic and accessibility aims defined by the team. We chose to make it out of cork since it is a material that is extremely cheap, resistant, environmentally friendly and is also a good thermal insulator. All the electronic components are assembled in a one-piece only structure, which has 4 floors. The first contains a switch and a battery; the second contains an Arduino Nano Every; the third contains a BMP280 sensor, as well as a INA219 voltameter; finally, the last one contains an antenna APC220 and a BMP280 sensor. Every floor is accessible as they can be easily unattached and attached to each other. Next to the second floor is the thermoelectric generator to make sure it has contact with the heat from our components and with the cold from its exterior. The last floor is open to make sure the BMP280 reads accurate values: considering we are going to maintain the heat inside our CanSat, the other BMP280 sensor might have read false values if it were in a different location. The lid was designed to have an easy access to the components, and it is made from PetG as it needs to resist to a force of 500 N.
Additionally, a recovery system was also planned. The recovery of the CanSat is assured with a parachute, specifically a fluorescent one for a better tracking of the descent trajectory of the satellite. The material used for the parachute consists of a ripstop fabric, designed in a hemispherical shape, due to its increased resistance to tearing and ripping in comparison to other fabrics. By making a circle with a radius of 20.58 centimeters, the parachute provides enough drag to achieve a terminal speed of 8 m/s. It comes with ropes of nylon, strong enough to provide a secure landing for the satellite.
In terms of data transmission, we planned for radio communication through two antennas, one responsible for sending the signal and the other for receiving it. The first one (APC220) we incorporated in the satellite, so it needs to be isotropic, which means, capable of transmitting the same amount of energy in all directions. The second one was located in the ground station, purposefully pointed towards the CanSat, during its movement, in order to collect the data to be transmitted to the computer, followed necessary graphing. Therefore, our group built a Yagi Uda antenna for being directional, receiving waves mainly from one direction and allowing interference to be minimized. However, for safety, we decided to buy an antenna as a backup plan, in order to ensure an effective data collection.
The project was promoted mainly via social media, such as our Instagram page and YouTube channel This made our ideas more accessible to young people in our school community and allowed us to track our progress. In addition, we created a website where all of the main information is neatly outlined. Our Instagram was especially active during the final, providing imaging on the rocket launch to well over 100 accounts. In summary, we reached over 600 accounts in 30 days having an impressive 586% of growth. Our project was also promoted by Pavilhão do Conhecimento and our team made an appearance in Portuguese national news program, SIC Notícias and CMTV.
This competition was an excellent learning opportunity. Our team had to work under constant pressure and deal with unexpected complications. With all of this, we saw our efforts being rewarded with the arrival of the long-awaited final in Ponte de Sor. Five days of dedication and focus on our project that gave us a unique experience.
On the first day, after settling in and making some adjustments to our satellite, we were able to try it out in a test launch, in which it was lifted by a drone until it reached a kilometer in altitude and then dropped until it hit the ground. Every small step was an achievement, and this successful first launch was no exception.
The second day started with the initial presentation, where our team had to present its idea in front of the juries. We used the rest of the day to finalize our cansat, which involved a lot of testing and tweaking, with special attention to the jury's comments that raised some challenges, making the complexity of the project even more apparent.
The next day was the final launch, which, due to technical failures, did not meet our expectations. Just before our cansat reached its peak, our antenna stopped receiving data, which compromised the completion of both missions. However, the competition was not yet over, and the final presentation was still missing. Back at the workplace, we set out not to give up and to overcome the situation together, challenging our ability to work as a team. We started by recovering our cansat and, seeing that it was intact, we looked for a possible cause of the occurred. In fact, our satellite had been on for more than twenty minutes, heating up progressively, waiting to be launched, which caused the processor to overheat and made it impossible for the sensors to read data.
That being said, based on some tests, we tried to do science proving the ineffectiveness of our idea. In the final presentation, we exposed the results and conclusions we reached, relying on data obtained by another team. On the fourth day, once the stages of our project were concluded, we were able to get to know some people better, interacting with other participants.
Finally, on the fifth and last day, the awards were given to the winning team, as well as to others for their highlight in certain components. Although we did not receive any awards, we felt happy to be there and satisfied with our journey.
It was, without a doubt, an enriching experience that allowed us all to develop technical skills and learn important lessons about resilience, leadership, and perseverance. Participating in this extracurricular project showed us how a challenge can be turned into a real opportunity of growth.
