The International Space Station

The story

From enemies to neighbours

For many years the United States and the Soviet Union were rivals in space. But after the end of the Cold War, in 1991, things changed: the two countries began to cooperate. In 1995 the first American shuttle docked with the Russian space station Mir, and astronauts and cosmonauts lived together in space. It was a dress rehearsal for an even bigger station, built by many countries: the International Space Station, abbreviated ISS.

The project brought together five space agencies: America's NASA, Russia's Roscosmos, Europe's ESA, Japan's JAXA and the Canadian Space Agency. Each built parts at home, and all the parts had to fit together perfectly in orbit, 400 kilometres up, without anyone being able to test them together first on Earth.

A puzzle in space

The first brick, a Russian module called Zarya, “Dawn”, was launched on 20 November 1998 from Baikonur. A few weeks later, in December, the shuttle Endeavour brought Unity, the first American module, and the astronauts connected it to Zarya with a manoeuvre using the robotic arm. Since then, over more than twenty-five years and with more than forty assembly flights, the station has grown piece by piece, with new laboratories, solar panels, pipes, nodes and windows.

On 2 November 2000 the first three residents arrived, the American Bill Shepherd and the Russians Yuri Gidzenko and Sergei Krikalev, who lived on board for more than four months. Since then the station has been inhabited without a break. Today there is usually a crew of seven, who change about every six months and travel on the Russian Soyuz craft and the American capsules.

What it is like

Fully assembled, the station is about 109 metres long and 73 wide, roughly the size of a football pitch, and weighs over 400 tonnes. It is the biggest human-made object in space. It travels at about 28,000 kilometres an hour and goes round the Earth in 92 minutes: the astronauts see the Sun rise and set sixteen times a day. There are laboratories for experiments, a gym, where every day the astronauts exercise for two hours so as not to lose muscle and bone, sleeping quarters, a toilet and a dome with seven windows for looking at the Earth.

Europe and Italy played an important part: many modules, including the nodes Harmony and Tranquility, and the Cupola, the panoramic window, were made in Turin, at a Thales Alenia Space plant. The European laboratory is called Columbus and has been in orbit since 2008.

A day on board follows Greenwich time: the astronauts wake up, have breakfast, take part in a short meeting with the control centres in Houston and Moscow, and then spend the hours on experiments, repairs and maintenance of the systems, because such a complicated machine always needs care. In the evening there is time to phone home and watch the Earth gliding by under their feet through the windows.

Life without weight

On board the station everything floats: the astronauts sleep in sleeping bags tied to the walls, eat special food with straws and drink water from pouches. They use machines that recycle water, even from breath and sweat. They carry out experiments that would be impossible on Earth, because without weight materials, flames, cells and plants behave differently. Among the Italian astronauts who have lived on board are Umberto Guidoni, Paolo Nespoli, Luca Parmitano and Samantha Cristoforetti, who in 2022 became the first European woman to command the station.