Offenburg Students Send Measuring Devices into the Stratosphere Once Again

During the flight, the interdisciplinary team of ten students from various degree programs led by Prof. Dr. Dragos Saracsan plans to conduct various measurements and experiments, just as the previous groups did in 2019 and 2020. To this end, a padded capsule weighing no more than 2.3 kilograms and equipped with a data logger will be attached to the latex balloon, which is filled with approximately 5,900 liters of helium. The data logger records GPS data, external and internal temperature, humidity, altitude, speed (speed over ground), and pressure. Cameras mounted on the capsule will record the flight from various angles. However, the “main passengers” are “Bacillus spizizenii” (DSM618 Bacillus spizizenii subgroup B subtilis wild type), yeast (a microorganism), and mung bean sprouts (a more complex, higher-order organism).

In an experiment, the students aim to use the well-studied bacterium “Bacillus spizizenii”—which can form highly resilient spores—to determine which factors enable microorganisms to survive under extreme, Mars-like conditions. This is important for space exploration because surviving Earth-based microorganisms could contaminate other planets, such as Mars, and lead to false positives in the search for extraterrestrial life. The study will test the effects of UV radiation, cold, and pressure on living and dying cells in comparison to surviving spores. As part of a bachelor's thesis, the focus is on how yeast (a microorganism) and mung bean sprouts (a more complex, higher-order organism) react to extreme negative pressure. Since conditions in the stratosphere resemble those that might prevail in future space stations or transport rockets, this research could yield a tangible engineering advantage: If life support systems or cargo compartments in space could be operated at a lower internal pressure—for example, 15 mbar instead of the usual Earth pressure of approximately 1,000 mbar—the mechanical stress on their outer shells would decrease dramatically. This, in turn, could lead to massive savings in materials, weight, and costs. To test this, the samples will be flown into the stratosphere in a capsule attached to a balloon. After landing, the morphological (structural and external) changes in the yeast and the sprouts will be analyzed and compared with a control group that remained on Earth under normal ambient pressure.

The students will track the balloon’s flight using a GPS module and follow the position data displayed on a map with two vehicles in order to recover the capsule as quickly as possible after landing. They currently estimate a flight time of approximately three hours and a distance traveled of about 67 kilometers.