Washington  - The space shuttle Discovery was nearing the International Space Station for a planned docking later Tuesday.

The Discovery is to deliver the fourth and final solar panel to the International Space Station on a construction mission that will enable it to double the size of its crew to six astronauts. Three spacewalks are planned to install the solar panels and conduct other construction projects.

The mission will also deliver Japanese astronaut Koichi Wakata, who is slated to join the permanent crew on the orbiting space station.

In recognition of the Japanese crew member, the first permanent ISS resident from that country, Discovery astronauts awoke on Tuesday morning to Radio Exercise, a song used by Japanese schoolchildren to exercise, and performed by the Tokyo Broadcast Children's Choir.

Discovery was approaching the ISS at a rate of 965 kilometres per 90-minute orbit for the planned 5:12 pm (2113 GMT) docking.

The shuttle launched Sunday after weeks of delays caused by concerns about hydrogen fuel valves and a later leak in a fuel vent.