The U.S. space shuttle Endeavour has undocked from the International Space Station, heading back to Earth following a mission that included a series of spacewalks to improve and expand the space station.

Endeavour left the orbiting outpost Tuesday, beginning the long journey home that will end with a landing Friday at the Kennedy Space Center in the southeastern U.S. state of Florida.

Endeavour's 11-day mission at the space station included five spacewalks during which shuttle astronauts installed an external platform on the station's Japanese lab, known as Kibo, which means "hope". The platform will allow scientists to conduct experiments in the vacuum of space.

The shuttle astronauts also conducted maintenance work on the station.

Japan's Koichi Wakata is returning to Earth with Endeavour's six other astronauts after spending more than four months on the space station. U.S. astronaut Tim Kopra replaced Wakata at the station, joining its five other occupants.

Endeavour lifted off on its current mission on July 15. The U.S. space agency NASA's next shuttle flight to the station is scheduled for August.

Some information for this report was provided by AFP, AP and Reuters.