Radiation and microgravity effects observed in the insect system Carausius morosus

Abstract

Among the biological problems that arise in long duration space- flights weightlessness and ionizing radiation appear to be the main risk factors. A precise differentiation between the effects of eitherenergy deposition by heavy ions or microgravity alone and their com- bined action has succeeded for the first time with the experiment on Carausius morosus embryos flown in BIORACK during the D1 mission. It was clearly demonstrated that microgravity reduces the hatching rate and amplifies the effect of heavy ions with respect to the frequency of body anomalies. In the meantime, Carausius morosus eggs were exposed during two further spaceflights, Cosmos 1887 and 2044. The studies in these experiments were done with emphasis on the mor- phological differentiation during embryogenesis. First results of theCosmos 2044 flight on hatching rate, growth kinetics, vitality and frequency of anomalies are presented and compared with those of the previous flights. These data indicate that in radiation protection an additional problem will be posed by a potential modification of radiobiological effects by microgravity.