The potential (radio-)biological impact of launch vibration

The differences observed between microgravity exposed samples and 1×g control samples on ground in a typical cell biological space experiment may be explained by unwanted side-effects like cosmic rays, launch vibrations or acceleration effects. This study investigated the impact of vibrational stress accompanying a typical launch in the field of radiobiology. Cultures of primary bone marrow cells were hard-mounted on a vibration table in a direction parallel (launch direction) and perpendicular to the cell culture's substrate. The cell cultures were then vibrated according to the qualification tests of Biobox space hardware. The g-levels in those separate directions measured 11.3×g and 4.5×g rms, respectively. Expression levels of six genes controlling apoptosis or genome damage/repair (c-Fos, Gadd45a, p21, Mdm2, Bax and Hspa4) were quantified with real-time PCR based on a panel of stable genes. A significant change in gene expression was seen in the launch direction. Considering the one-shot philosophy of space experimentation, simultaneous vibration of ground samples at launch of experiments should be mandatory for biological experiments.