FIG. 9.

Biostack experiment, a method to study the biological effects of single heavy ions of cosmic radiation. (A) The complete Biostack experiment package (about 10 × 10 × 10 cm in size) accommodated in a hermetically sealed aluminum container was stowed inside the spacecraft during several space missions (Apollo and Spacelab) and exposed to cosmic radiation. (B) The Biostack consists of a sandwich of monolayers of biological objects in a resting state (in this example, B. subtilis spores) mounted on a particle track detector. After irradiation and processing of the track detector, the biological effect on individual spores was investigated and correlated to impact parameter, i.e., the distance from the particle's trajectory (C) (17). CN, cellulose nitrate; PC, polycarbonate; PVA, polyvinyl alcohol.