MOSCOW (AFP) - How do you calculate the weight of a gigantic man-made object floating around in the supposed "weightlessness" of space? With a big rocket and a little brainpower, Russian scientists said Saturday, as they announced plans to use their Progress space resupply ship to measure the mass of the orbiting International Space Station (news - web sites) (ISS). "We do not know the mass of the ISS precisely enough," Vladimir Solovyov, chief of the Russian mission control team supervising the current Progress mission to the ISS said. "The station is refueled from time to time, something new is...