Buoyancy "downward" direction. The center of buoyancy of an object is the centroid of the displaced volume of fluid. Archimedes' principle is named after Archimedes of Syracuse, who first discovered this law in 212 B.C. For objects, floating and sunken, and in gases as well as liquids (i.e. a fluid), Archimedes' principle may be stated thus in terms of forces: — with the clarifications that for a sunken object the volume of displaced fluid is the volume of the object, and for a floating object on a liquid, the weight of the displaced liquid is the weight of the object. More
Neutral buoyancy simulation as a training aid returned to McDonogh to perform a post-mission evaluation of the EVA. The post-mission evaluation verified the value of using neutral buoyancy simulation training before attempting all of the EVA tasks while wearing a pressure suit and working in the hostile environment of space. Aldrin himself recognized some minor flaws of neutral buoyancy training, but described the method to have a "considerable advantage" over Keplerian trajectory aircraft. After the successful EVAs in the Gemini XII mission, NASA constructed tanks for neutral buoyancy simulation: The Water Immersion Facility at the Manned Spacecraft Center and the Neutral Buoyancy Simulator at Marshall Space Flight