STEM education is a new interdisciplinary concept that fuses the learning objectives of sciences, technology, engineering and mathematics. After concluding that many undergraduate students are not interested in STEM disciplines and taking into account the admiration for space, a series of educational activities have been developed to increase their engagement in this field. The proposed project-based workshops are diverse: designing and launching High Altitude Balloons; building water rockets; protecting an egg from the impact with the ground after being dropped from a drone; designing and building paper gliders; 3D printing customzied quadcopters, etc. One of the most impressive activities consisted of designing, manufacturing and launching a low-cost high-altitude balloon to take photographs of the stratosphere. To do so, a kit was developed and validated: this contains a GPS tracker, a camera, an EPS box, a parachute and a helium balloon. The selection of the components was done trying to minimize the operational cost and maximizing the reliability of the design; the final High Altitude balloon weights 350g and has reached altitudes around 27.000 - 30.000 m. The educational activity is a 3 to 4 days workshop in which the students go through the process of building their own HAB, launching it and eventually recovering it to obtain the photographs. The activities have been implemented in multiple schools and high schools in Catalonia, and all of them have shown excellent results. After evaluating the reasons why the workshops were well-received, it was concluded that students were more implicated than in standard lectures because they went from a passive to an active mindset. Moreover, the workshops were designed to make them become curious and increase their eagerness to learn, while forcing them to think and to take important decisions that ultimately influence the final result, rather than observing and admiring somebody else’s work
