Cosmic-Ray Tracks in Plastics: The Apollo Helmet Dosimetry Experiment

Abstract
Counts of tracks from heavy cosmic-ray nuclei in helmets from Apollo missions 8 and 12 show variations caused by solar modulation of the galactic cosmic-ray flux. Specific estimates of the biological damage to certain nonreplaceable cells by track-forming particles during these space missions indicate that the fraction of deactivated cells could range from a lower limit of 3 × 10 -7 to an upper limit of 1.4 × 10 -4 .