The TOADY project is concerned with the development and use of a weather balloon probe. It was created in collaboration with the DHBW Ravensburg, which offers the association the opportunity to develop its own electronic components for the balloon probe as part of several balloon launches. The aim is to carry out acoustic experiments at high altitudes in addition to classic atmospheric measurements.

But why is a student space club involved with weather balloon probes? The answer is simple: a balloon probe has a lot in common with a satellite! Both have to function autonomously under extreme environmental conditions (for their respective altitudes) and can at most exchange data with ground personnel via a radio link. The launch experience is also comparable: Once launched, there is no turning back, even with a weather balloon, and manual intervention is impossible - everything depends on the quality of the autonomous systems on board the probe!

TOADY's weather balloon will reach an altitude of around 36,000 meters before the envelope bursts and the probe descends to the ground on a parachute. The ascent goes through the troposphere with an ambient temperature of approx. -50° C into the stratosphere, where the UV radiation is considerably higher than even in the high mountains. During the flight, weather and radiation data are therefore recorded, movement parameters are determined to reconstruct the flight path without GNSS and sound measurements are also carried out. 

After the first successful flight in May 2025, further missions with optimized electronics are planned in order to refine the current experiments and carry out more precise measurements. In the long term, the project aims to provide a platform for students and young researchers to explore autonomous measurement systems and experimental atmospheric research.

The data obtained will serve as the basis for various future experiments.

On the one hand, the intention is to reconstruct the balloon's flight path based solely on the data from its motion and environmental sensors. The calculated route will then be compared with the recordings from the GNSS receivers. If there is a good match, the trajectory will be calculated on board the balloon probe in future missions and transmitted to the ground by radio.

The second exciting idea for future experiments is the investigation of possible SOFAR (SOund Fixing And Ranging) effects in the atmosphere. This is originally a physical phenomenon of sound transmission in different layers of water, which is known from oceanography. However, current theories and research from the USA indicate that similar effects can also occur in certain layers of air.