sentences:  The skills of astronautical hygiene are already being applied for example, to characterise moon dust and design the measures to mitigate exposure during lunar exploration, to develop accurate chemical monitoring techniques and use the results in the setting SMACs.Of particular interest from a biological perspective are the effects of reduced gravitational force felt by inhabitants of spacecraft.Often referred to as "microgravity", the lack of sedimentation, buoyancy, or convective flows in fluids results in a more quiescent cellular and intercellular environment primarily driven by chemical gradients.