• sounding balloons
• near space environment
• low-cost spacecraft testing
• high altitude balloons
• weather balloons

The aerospace industry is currently growing at a fast pace. Differently from what happened in the recent past, space is increasingly seen as a business in which to invest. This has meant that more and more private companies became interested in taking part into this market. Despite this, the space sector still requires big investments. For these reasons, in recent years the interest in cheaper solutions has considerably increased. Following this principle, the main goal of the work here reported was to create a low-cost near-space platform for experimenting and testing on space hardware. The idea is to use the most common type of high-altitude balloon, i.e. sounding balloons, which are nowadays available at very low cost from commercial vendors and freely operable. This because they represent a simple, quick and economical way to launch a payload in a near space environment.
The work reported in this thesis is a summary of the results and the knowledge about high-altitude balloons derived from both a launch campaign composed of 5 launches, the ISM-HAB project, carried out between September and November 2018 and another launch performed in July 2019, denominated AIS-HAB. The ISM-HAB activity is the result of a collaboration between Eutelsat SA, the Italian company MBI Srl, the Department of Aerospace Engineering and the Department of Information engineering, both from the University of Pisa. The AIS-HAB experiment was carried out again by MBI and the University of Pisa, this time in collaboration with the Italian space agency (ASI).
The ISM-HAB project aimed to collect RF power measurements assessing the levels of interference in the ISM bands, while the AIS-HAB launch purpose was to test the reception capabilities of the AIS signal, which is used for maritime surveillance, on board of stratospheric balloons. The balloons reached a maximum altitude of 32 km. At such altitude, the signal was collected from sources scattered over a very large portion of Earth, thus emulating what would be experienced by a LEO satellite. Along with the primary objective of RF measurements, the project offered an excellent opportunity to perform the characterization of the dynamic environment of the HAB platform, in view of the future use of such system for space hardware testing.
The design phase of the missions, along with the composition of the platform and the integration of the payload are fully described. Because it is not possible to have real-time data during the flight, it is essential to recover the payload for the mission success. Thanks to careful planning it was possible to conduct a total of six flights without ever losing the payload. The operational phase is reported starting from the organization of the missions, based on the flight predictions. A flight model and a trajectory simulator has been developed to predict the trajectory of the flight and choose the launch site. The launch operations are described, starting from the inflation of the balloon, up to the recovery operations. RF measurements and data relative to the payload dynamics obtained during the flights are reported and commented. In particular, it is described how the temperatures and the dynamics of the platform vary along the flight trajectory and how these data could be used to design a payload stabilization system for the high-altitude portion of the flight.