With a team of PhD and undergraduate students of physics and biology from different German Universities I participated in a student competition (BEXUS) of the German Space Agency, DLR, and the European Space Agency, ESA. After 9 months of part-time preparations, our team named “DOLS” (Diversity and Origin of Life in the Stratosphere) participated in the balloon launch campaign at Esrange near Kiruna, Sweden. Physics students had prepared an air-sampling device and the necessary electronics while I took care of the biological part (air filters, analysis of results, sterilization, planning of DNA sequencing, scientific collaborations etc.). A code-sharing platform (bitbucket.org) proved useful and a blog was created to document the project.
The balloon launch was successful and we collected a number of air samples from different altitudes (up to 26.000 m), but finally different contamination problems and the extremely low DNA concentrations proved to be too challenging. So we were not successful in identifying microorganisms from the stratosphere, but cannot rule out the possibility that they exist (and possibly were below our detection threshold).