The Italian cosmonaut who flew with space tourist Mark Shuttleworth last month is completing an experiment that could have major implications for the way we treat osteoporosis sufferers. Flight engineer Roberto Vittori is back at Star City near Moscow this week attempting to shake the strength back into his bones using a simple vibrating plate which he stands on to exercise. Bone wastage is a big problem for anyone who spends even just a short time in orbit – and would certainly blight any manned trip to Mars unless researchers can find a way to counteract it.