This is a digital artist's concept of the International Space Station. It is to be powered by an acre of solar panels and weigh almost 500 tons. The pressurized volume of the station will be equivalent to the space inside two jumbo jets.  Station modules are being provided by the U.S., Russia, Europe and Japan.  Canada is providing a mechanical arm and "Canada hand."  16 countries are co-operating to provide a state-of-the-art complex of laboratories in the weightless environment of Earth orbit. The first piece of the station was launched in June 1998. (Courtesy of NASA)