More than 80 flights will be necessary to complete the International Space Station. Most crew members and supplies will travel to the station on American space shuttles or Russian rockets, mainly Soyuz and Proton. The ESA and Japan plan to develop supply vehicles to be launched on the ESA's Ariane 5 and Japan's H-2 booster rockets. The space station's crew will measure the effects of space conditions, such as apparent weightlessness, on biological specimens, including themselves. They will also check the effects of space on the production of materials such as semiconductor wafers and glass crystals.
Semiconductor wafers are the starting materials for computer chips.
The space station will function as an observatory, laboratory, and workshop. Its instruments will examine detailed features on earth's surface and in earth's atmosphere. The instruments will also observe the sun and other astronomical objects without the veiling interference of the atmosphere. The major value of having a space station is that all the equipment needs to be carried into space only once. Also, the station can be used again and again by visiting astronauts and cosmonauts.