A space station is constructed in the shape of a wheel 15 m in diameter, with essentially all of its 4.0105 kg mass at the rim.

A space station is constructed in the shape of a wheel 15 m in diameter, with essentially all of its 4.0×105 kg mass at the rim. Once the station is completed, it is set rotating at a rate that requires an object at the rim to have radial acceleration g , thereby simulating Earth's surface gravity. This is accomplished using two small rockets, each with 150 N thrust, that are mounted on the rim of the station.