The US space shuttle Endeavour docked on schedule on Wednesday with the orbiting International Space Station, NASA announced.

At 5.06am GMT Endeavour Commander George Zamka backed the space shuttle "into pressurised mating adapter number 2 on the International Space Station's Harmony node," NASA said in a statement.

"The two spacecraft were flying 225 miles (362 kilometres) up and off the northern coast of Spain at the time they docked."

The manoeuvre was broadcast live on NASA TV.

The shuttle and station crews are scheduled to open hatches and hold the traditional welcome ceremony at 7.04am GMT.

Endeavour astronauts on Tuesday finished routine inspection of the thermal protection system on the orbiter's wing leading edges and nose, NASA said.

The Endeavour and its crew of six astronauts blasted off on Monday carrying a seven-windowed dome observation deck for the ISS.

Built for NASA by the European group Thales Alenia Space in their Turin factory, the cupola will provide unparalleled panoramic views of Earth and space.

A long, difficult job

Six windows arrayed along its sides and another on top ? all protected against the impact of tiny meteorites ? will provide an unprecedented, wide-ranging view for those onboard and help crew members monitor spacewalks and docking operations.

The cupola can accommodate two crew members at a time, and is equipped with portable workstations that can control station and robotic activities.

Installing the Tranquility module amounts to a major construction job, requiring a team of two astronauts to undertake three spacewalks lasting six and a half hours each, the National Aeronautics and Space Administration said.

Once the room is in place, the space station will be 90 percent complete.

The mission, one of five scheduled for NASA's three shuttles before the programme ends later this year after a 29-year run, comes as the US space agency re-evaluates its future after President Barack Obama effectively abandoned its plan to send astronauts back to the moon by 2020.

The Constellation programme was intended to develop a successor spacecraft to the shuttle, which could carry astronauts to the moon. They could then use a lunar base to launch manned missions to Mars.

Constrained by soaring deficits, Obama submitted a budget to Congress that encourages NASA to focus instead on developing commercial transport alternatives to ferry astronauts to the ISS after the shuttle programme ends.

The ISS, a joint project involving 16 countries, has cost around $100-billion, mostly funded by the United States.

Under Obama's new budget, the floating research station could see its life extended by five years until 2020.