Space Shuttle Endeavour has been given the green light for takeoff tomorrow on a crucial mission that will double the size of the International Space Station (ISS) crew.

The cargo will form the basis of Nasa's plans to have a permanent crew of six in orbit to increase the amount of useful scientific data that the Space Station can create.

This mission takes up new sleeping quarters, vital recycling facilities, the first refrigerator and an extra toilet, which will be useful considering a series of malfunctions earlier this year.

"When the fourth Space Shuttle mission of the year is complete, the ISS will have all of the key systems needed to turn what is now a three-bedroom, one-bathroom home for three, into a five-bedroom, two-bath residence for six," said Nasa.

The 15-day mission will also see essential maintenance on the solar arrays that power the station, and allow one of the crew members to return home.