What are we going to do?

The stratosphere is a potential habitat for exotic life forms of relevance to industry and human health. We aim to analyse these life forms in situ, with the long term goal of bioprospecting for novel ways of coping in extreme habitats. The air and clouds contain bacteria and fungi. When these fall to earth they are suspected carriers of disease. Craig Venter for instance is undertaking a massive effort sequencing genomes of airborne life. But how far up does this go? Ultrahigh altitude clouds are still ice crystals condensed around dust, like “normal” clouds: An Astrobiologist would tell you this is an excellent hiding place for life! As long ago as 1935, the Explorer 2 Balloon found fungi and bacterial spores above 35,000ft; similar experiments have been performed since then (rev Griffin Aerobiologia (2008) 24:19–25). However, samples are snatched blindly and analysed on the ground, hours or days later. After such journeys, can researchers be sure they have not just contaminated samples terrestrially? And are they truly representative of high altitude life after enduring rapid temperature and pressure changes during descent? By contrast, we will perform active molecular biology experiments to study life in situ at high altitude. This has never been done before.