High-Altitude Ballooning Student Research with Yeast and Plant Seeds

Weather balloon flights provide affordable access to a space-like environment for student research. Typical flights last for 2.0-2.5 hours and reach altitudes of approximately 30 km. Payloads are exposed to intense cosmic and ultraviolet radiation, temperatures below -60° C, and atmospheric pressures of approximately 0.01 atmospheres. We report on simple laboratory procedures intended primarily for high school and middle school students in studying the effects of high-altitude balloon flights on yeast and plant seeds. Saccharomyces cerevisiae, Raphanus sativus, and Brassica rapa were flown on two weather balloons inside and outside of payload containers to an altitude of approximately 27.5 km. After the flights the yeast cells were plated on YED media and incubated to assess survival and mutation rates. The seeds were planted to assess survival and variation in quantitative traits. We also discuss connections to disciplinary core ideas in the Next Generation Science Standards (NGSS) (NGSS Lead States, 2013) and provide an overview of further laboratory investigations designed to enhance students’ understanding of the effects of radiation on living organisms.