Artificial Gravity

Seems to me that it would havebeen anyone's wild guess that muscles need gravity to work againstto remain strong. Why didn'tplanning fora rotating modulego into the ISS? To expand upon the idea that external tanks couldhave beenstockpiled on orbit forretro-fittinginto pressurized work labs, twotanksjoinedat thenose could be spun together for different gravities on different floors with, say,1-G at the bottom floors. Four such tanks joined at the nose with flat solar panels along their backs could resemble a giant ceiling fan, but I digress. I ratherenjoy my ceiling fan here in FL. SSI is founded by the man who knew by numbers and intuition that spheres, toruses, and cylinders that rotate are thebest places for an expanding technological civilization, not the wrong gravities of other planets and certainly not zero-gee environments.