Four hundred kilometres above the Earth, a remarkable structure is taking shape. From a distance it looks like some kind of sci-fi mechanical insect with several sets of shiny rectangular wings attached to a cylindrical, segmented body.

This is the International Space Station, a vast orbiting laboratory whose construction has been hailed as the most ambitious feat of engineering in human history. The space stations ‘wings’ are huge solar panels for generating electricity and the body consists of several ‘modules’ providing living quarters for astronauts and laboratories for a range of experiments and space observation studies.

The space station, a collaboration between 15 countries, is being assembled piece by piece. More than 50 missions, mostly by the shuttle, will be needed to transport and assemble all the components. When it is complete the final structure will be longer than a soccer pitch at 108m, will weigh 450 tonnes and will have more than 1200 cubic metres of pressurised space. It will support a permanent crew of seven astronauts.

The International Space Station is the latest and most sophisticated effort to keep human beings in space for extended periods of time. In the 1970s the Soviet Union launched a series of small space stations in their Salyut programme. The US launched Skylab in 1973, and it remained in orbit until 1979 before eventually falling back to Earth, with debris being scattered across parts of western Australia.

The Russian space station Mir was highly successful, beginning life in 1986 with the launch of its first module. It was gradually expanded and remained almost fully occupied for 13 years before returning to Earth in 2001 after more than 86,000 orbits.