A compact body mass measuring device for space flight applications.

During spaceflights, it is important to measure an astronaut's body mass ('weight'), both for investigating the influence of the space environment on the human body and for monitoring the physical (health) condition of the astronaut. This paper reports the development of a mass measuring device that is compact, user friendly, and has an absolute measuring accuracy better than 60 gram. The measurement accuracy turns out to be restricted by the way a human body is configured by nature and not by the instrument itself, that has an accuracy much better than required.     

Protozoa as model systems for the study of cellular responses to altered gravity conditions.

The orientation behavior of Paramecium changed in a similar way after transition to conditions of free-fall in a sounding rocket and after transition to conditions of simulated weightlessness on a fast rotating clinostat. After a period of residual orientation, Paramecium cells distributed themselves randomly 80 s (120 s) after onset of free-fall (simulated weightlessness). Swimming velocity increased significantly; however, the increase was transient and subsided after 3 min in the rocket experiments, while the velocity remained enhanced even during 2 h of rotation on a fast clinostat. Trichocysts were present and without morphological changes in Paramecium cells which had been exposed to a rocket flight, as well as to fast or slow rotation on a clinostat. Regeneration of the oral apparatus of Stentor and morphogenesis of Eufolliculina proceeded normally on the clinostat. The results demonstrate that the clinostat is a useful tool to simulate the conditions of weightlessness on earth and to detect gravisensitive cellular functions.