One particular experiment that I remember from a visit to a Science Center is the one involving a revolving platform and a gyroscope. The user spins the gyroscope - a heavy wheel on an axle and stands on the platform which is free to rotate about its vertical axis. As I distinctly remember, suddenly moving the gyroscope, rotating it while holding the ends of the axles, caused me, the gyroscope and the platform to rotate left or right. If an astronaut on a spacewalk holds a spinning gyroscope twists it right or left or in any direction, will it not cause him to rotate? Could such a device be used to orient the astronaut without using external jets or rockets?