Tardigrades on board of the STS-134 space flight

The joint ASI-AM DAMA mission supported a set of scientific experiments executed in short-duration microgravity on board the Space Shuttle docked to the International Space Station. BIOKIS payload (by Kayser Italia) took advantage of the last STS-134 Endeavour mission lasted 16 days. It hosted a multidisciplinary set of experiments in the field of biology and dosimetry. Among them, the TARDIKISS project investigated the responses of live desiccated tardigrades, multicellular heterotrophic organisms, under space stresses. In particular, specimens of Paramacrobiotus richtersi and Ramazzottius oberhaeuseri have been used. The experimental flight units were hosted into the Biokon, a standard transportable container. In addition, a Laboratory Control sample was maintained in Modena laboratory for the duration of the flight, while a post-flight Temperature Control sample was exposed to the temperature profile experienced by tardigrades during the mission. For both species, the Flight animals did not show differences in survival with regard to Laboratory and Temperature control animals. Only in R. oberhaeuseri differences have been recorded between Flight and Temperature Control samples. Specimens of P. richtersi from Flight, Laboratory and Temperature control samples have been reared in lab. Flight females laid eggs with normal shape; several eggs have been able to hatch, and newborns exhibited, when adult, normal capability to reproduce. The comparative analysis of the antioxidant metabolism between Flight and Temperature control samples did not evidenced significantly differences between the two groups. These data confirm that tardigrades represent a useful animal tool for space research. The authors thanks the Italian Space agency, Italian Air Force and Kayser Italia S.r.l.