How to get the Mars space ship's centrifuge (diameter: ~20 meters) on LEO with Ares V? The radiation shield (liquid water) between centrifuge's hollow walls has mass of 160 metric tonns, so probably the centrifuge has to be shoot on LEO without the water. Ares V's payload is "only" 130 metric tons. Maybe it's possible to use only 130 metric tons of water so that one Ares V is enough for the radiation shield. There should be 8 "bed rooms" with doors for 8 people, showers and toilets in the centrifuge, because the centrifuge is the place where the astronauts/cosmonauts will be almost whole the flight time. But how many Ares V vehicles is needed for the centrifure (diameter: ~20 meters, width: ~4.5 meters, volume: ~1414 m[tex]^3[/tex])? How much energy is needed to spin this centrigure 6 RPM? Is this centrifuge beyond our engineering capabilities? Thanks!